Annual/Termination Reports:

[02/01/2010] [02/22/2011] [02/23/2012] [01/10/2013] [12/19/2013] [10/02/2014]

Report Information

Participants

Starr, J. L. (j-starr@tamu.edu) - Texas AgriLife Research; Davis, Richard (richard.davis@ars.usda.gov) - ARS, Tifton, GA; McGawley, E. C. (emagawley@agctr.lsu.edu)- Louisiana State University; Agudelo, Paula (pagudelo@clemson.edu)- Clemson University; Robbins, R. T. (rrobin@Uark.edu) - University of Arkansas; Stetina, Sally (sally.stetina@ars.usda.gov) - ARS, Stoneville, MS; Eisenback, J. D. (jon@vt.edu) - Virginia Tech University; Timper, Patricia (patty.timper@ars.usda.gov)- ARS, Tifton, GA; Lacewell, R. D. (rdlacewell@ag.tamu.edu) -Texas AgriLife Research (Administrative Advisor).

Brief Summary of Minutes

The regular meeting of the S-1046 was called to order at 8:40 am on Jan. 8, 2010 in New Orleans, LA by James Starr.
Present: Jim Star, Richard Davis, Ed McGawley, Paula Agudelo, Bob Robbins, Sally Stetina, Jon Eisenback, Patricia Timper, and Ron Lacewell (Administrative Advisor).

A. Approval of Agenda - The agenda was unanimously approved as distributed.

B. Approval of Minutes - The minutes of the previous meeting were unanimously approved as distributed.

C. Open Issues - starr welcomed the group to New Orleans. He mentioned that several people who planned to be at the meeting could not be here due to the frigid temperatures back home (Kathy Lawrence, Gary Lawrence, and Charles Overstreet).

Lacewell expressed concern about the lack of participation and encouraged the group to apply for grant proposals.

Starr queried the group about meeting times: should we continue the rotation among the member states (TX, FL, GA, LA, MS, TN, AL, AR) or attach the meeting to another conference like we did this year? Although most of the people in attendance were satisfied with S-1046 being held in conjunction with the Beltwide Cotton Conferences, it was agreed that all members should be polled via e-mail. If we continue with the normal rotation, the next meeting will be in either Arkansas or Louisiana.

McGawley proposed that we perform some cooperative project as we had done in years past (but not done recently). One of the problems was that many of these projects were never published. We should indentify a common project that we can also publish.

Starr said that in the Business meeting, he was planning on appointing project coordinators who might facilitate initiation and completion of one or more common projects. One idea was that we conduct a survey to identify the root-knot species associated with major crops in each participating state.

D. State Reports (final year of S-1015)
Arkansas. Bob Robbins presented a project involving rotating soybean cultivars containing different resistance genes. Soybean cyst populations have been kept at low levels for 7 years. He has also been screening soybean lines from all over for resistance to the reniform nematode.

ARS Georgia. Richard Davis developed a new cotton line (GA120R1B3) with a high level of resistance to Meloidogyne incognita and improved yield and fiber quality. This was achieved through backcrossing and single seed descent. A germplasm release should be completed very soon. Patty Timper discussed two projects with Pasteuria. In one project, endospore densities increased to higher levels in a rotation with eggplant, corn, and peanut than in other crop rotations. The other project involved the effect of soil texture and nematicide treatment on a Pasteuria infecting reniform nematode.

ARS Mississippi. Sally Stetina presented several project dealing with reniform nematode in cotton. She is looking for new sources of resistance from hirsutum and other Gossypium species and evaluating molecular variability in the reniform nematode (microsatellite and SSR). She has found no link between variation and virulence or pathogenicity.

Louisiana. Ed McGawley is testing Agri-Terra and sister products on strawberry as an alternative to methyl bromide. The product controls both M. hapla and ring nematode. He has also been testing a chemical called Oraphyte and Pasteuria in turf.

Virginia. Jon Eisenback presented the findings of surveys of nematodes in soybean (mostly SCN) and corn (stunt, stubby root, lesion, and root-knot nematodes). He has also found a new root-knot in turf  M. lamicainae. This nematode has subsequently been found in other mid-Atlantic states. Damage threshold  40/100 cm3.

South Carolina. Paula Agudelo has an interest in intraspecific diversity of nematodes (mainly root-knot and reniform nematodes) and how this diversity influences management. She presented research on the effect of temperature on embryogenesis of the reniform nematode. She also has a study looking at the effect of crop rotation on the population structure (utilizing 7 microsatellite markers) of the reniform nematode. Corn has the greatest impact on the population structure, perhaps by selecting for survival of different genotypes.

Texas. Jim Starr is attempting to identify difference sources of resistance to M. incognita in cotton. He has conducted a half diallel analysis with 5 resistant cotton accessions from Mexico and identified at least 2 unique resistance alleles. He is also trying to develop cotton germplasm with resistance to both root-knot and reniform nematodes. In the near future, he plans to release a high O/L peanut cultivar with good resistance to root-knot nematodes, Tomato Spotted Wilt, and Sclerotinia blight.

E. Business meeting
Bob Robbins (Arkansas) was unanimously approved to be the next Chair of S-1046. Ed McGawley was unanimously approved to be the next Secretary. As a general rule, the secretary will be selected from the rotation 1 year out from the Chair.
Starr asked for volunteers to coordinate each of the three objectives. These coordinators would organize the common projects and develop uniform protocols. Stetina volunteered to coordinate Obj. 2 and Agudelo and Eisenback volunteered to coordinate the reniform and root-knot projects, respectively, for Obj. 3. No one was selected for Obj. 1 (Management) because the group did not think this objective was amenable to a common project.

Stetina suggested that we use SharePoint for sharing files and information over the internet. This program would be particularly useful once we establish common projects.

Adjournment:Meeting was adjourned at 3:45 pm by Jim Star.
Minutes submitted by: Patricia Timper

Accomplishments

As this is a new project there are no research accomplishments to report at this time. Participants have completed their initial organization into interest groups and individuals have been selected to coordinate regional collaborative efforts under objectives 2 and 3.

Publications

Impact Statements

1. No impact statements available due to the project having received approval for initiation in only December 2009.

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Report Information

Participants

Agudelo, Paula (pagudel@clemson.edu) Clemson University
Davis, Richard (rfdavis@tifton.usda.gov) USDA-ARS-Georgia
Dickson, Donald (dwd@ufl.edu) University of Florida
Eisenback, Jonathan (jon@vt.edu) Virginia Tech
Koenning, Stephen (stephen_koenning@ncsu.edu)
Lawrence, Gary (glawrence@entomology.msstate.edu) Mississippi State University
Lawrence, Katheryn (lawrekk@auburn.edu) Auburn University
McGawley, Edward (emcgawley@agctr.lsu.edu) Louisiana State University
Nguyen, Henry (NguyenHenry@missouri.edu) University of Missouri
Robbins, Robert (rrobbin@uark.edu) University of Arkansas
Starr, Jim (j-starr@tamu.edu) Texas A&M University
Stetina, Sally (Sally.Stetina@ars.usda.gov) Mississippi State University
Timper, Patricia (ptimper@tifton.usda.gov) USDA-ARS-Georgia
Lacewell, Ron (r-lacewell@tamu.edu) Texas A&M AgriLife

Brief Summary of Minutes

(Improved management of plant-parasitic nematodes through modern diagnostic tools and increased use of host resistance)

The meeting was convened at 1:00 PM in the Marriott Marquis Hotel in Atlanta, GA on January 7, 2011. Scientists in attendance (and their state designation) were: Agudelo (SC), Davis (GA), Dickson (FL), Eisenbach (VA), Koenning (NCSU), Lawrence (MS), Lawrence (AL), McGawley (LA), Nguyen (MO), Robbins (AR), Starr (TX), Stetina (MS), Timper (GA), Lacewell (Administrative Advisor, TX). Chen (MN) was absent.
The reading of the minutes from the previous were dispensed with and approved as distributed via email to members. Members gave oral state reports. With the impending arrival of bad weather in the Atlanta area, the meeting continued until 6:40 PM in order to include the business meeting. At the business meeting Stetina lead a discussion of cooperative activities for 2011 with reniform nematode. Members will collect specimens of reniform nematode from infested fields in their states. Single mature females will be dissected from root systems and quick frozen at -80 C in 1 M NaCl. Since these samples will contain dead nematodes there will be no need need for an APHIS permit from the USDA. Stetina and colleagues in Stoneville, MS where will extract and amplify DNA from these samples for molecular analysis. Eisenbach and Agudelo also indicated their intentions to cooperate on improving methods for identification of root knot nematode species. In other discussion, McGawley was elected a chairman for the 2011 meeting.
Lacewell then made comments from his standpoint as the administrative advisor to the group. First, he congratulated the members related to getting enthusiasm back into the team. The research members are actively working together to solve issues for agriculture including the horticulture industry.
The group met briefy for breakfast on January 8 and then departed to avoid the adverse weather.

Accomplishments

Objective 1: Integrate resistant cultivars with other nematode management tactics to reduce selection pressure on nematode populations and communities. <br /> (AR) I tested 161 soybean varieties new to the Arkansas Soybean Variety Testing program and 64 breeding lines and varieties from Southern Public Soybean Breeders for resistance to the reniform nematode (Rotylenchulus reniformis) in soybean (6 from Arkansas; 20 from Clemson; 20 from Missouri; 2 from USDA, Jackson, TN; 16 from Virginia Tech). All 296 soybean varieties in the 2010 Arkansas Soybean Variety Testing were also tested for Root-knot (Meloidogyne incognita) and Soybean Cyst Nematode races 2, 3, 5, and 14 (the most prevalent races in Arkansas). The results of this testing can be accessed at the following: http://www.arkansasvarietytesting.com/crop/data/5 administered by Terry Kirkpatrick.<br /> In a study I initiated in 2003 on the study of the effects of rotation of soybeans with 3 different soybean resistance sources (mode of resistance) to the soybean cyst nematode in St. Francis (Pine Tree Station) county, I have completed the eight year of the rotation in cooperation with Terry Kirkpatrick. When all rotations are compared the yield is best and the nematode numbers are least when Anand is the variety planted. A similar study rotating 3 Roundup Ready varieties with different resistance reactions has completed its fifth year at Pine Tree also. It became obvious during 2009 and became more pronounced in 2010 that some bio-control agent has become prevalent in this test as most of the plots at harvest had no detectable nematodes.<br /> <br /> (FL) The root-knot nematode tomato cultivar, Crista was tested for marketable yield and galling on roots in two spring and two autumn trials. Evaluations included fumigated and nonfumigated treatments and all trials included a root-knot nematode susceptible cultivar. In three of these trials fruit yield with nonfumigated Crista ranged from 33% to 113% greater than that of the nonfumigated susceptible cultivars, whereas in one trial fruit yield of Crista was 17% less than that of the susceptible cultivar. In three of the four trials when plots of Crista were treated with various fumigants (chloropicrin, potassium metam, 1,3-D, 1,3-D+chloropicrin) yield was increased from 7 to 42% over nonfumigated plots of Crista. In one trial, however, yield of Crista was decreased 21% when fumigated compared with nonfumigated Crista. Galling indices on nonfumigated Crista ranged from 0 to 2%, whereas galling on nonfumigated susceptible cultivars ranged from 29 to 53%. The low percentage galling of Crista vs. susceptible cultivars suggest that the root-knot nematode resistant Mi-1 gene in Crista was maintained and not broken by soil temperature.<br /> (AL) The reniform nematode, Rotylenchulus reniformis, is a leading economic pest in cotton in Alabama. Six soil types common to Alabama were evaluated for their effects on the reproduction of R. reniformis under irrigated and non-irrigated conditions. The test was conducted in microplots placed in a factorial within a RCBD replicated five times. The soil types evaluated were a Dothan sandy loam (S-S-C = 57-28-15), a Decatur silt loam (S-S-C = 23-49-28), a Hartsells fine sandy loam (S-S-C = 51-38-11), a Ruston very fine sandy loam (S-S-C = 59-33-8), a Lloyd loam (S-S-C = 52-23-25), and a Vaiden clay (S-S-C = 5-42-53). Significant interactions between soil type and irrigation occurred for nematode reproduction and yield. At harvest, R. reniformis populations were significantly higher (P <0.10) in the Decatur silt loam over the Hartsells fine sandy loam, the Ruston very fine sandy loam, and the Pacolet sandy loam. The Decatur silt loam also had higher populations than the Vaiden clay and the Dothan sandy loam by an average of 3,785 and 5,647 vermiform/150cc soil respectively. Soil types with greater than 50% silt + clay (Decatur silt loam and Vaiden clay) had an average of 83% more R. reniformis than those without. Rotylenchulus reniformis populations were higher in the irrigated plots by an average of 54% at mid-season and an average of 30% at harvest. The Vaiden clay yielded significantly higher (P <0.10) than all other soil types, while the Ruston very fine sandy loam yielded significantly lower (P <0.10) than all other soil types. Yields were significantly higher (P <0.10) in the non-irrigated plots. The combination of soil type and irrigation is directly related to R. reniformis reproduction and can potentially be used with other factors to predict cotton yield loss. <br /> (GA) Pasteuria species are bacterial parasites of nematodes. In a field study in Georgia, fewer Pasteuria spores were observed in the sandiest areas of the field and in locations treated with Telone than in the other locations. Similar numbers of spores were observed in the Temik treatment and the control. It is likely that there was greater leaching of spores below the sampling zone in the sandier areas. Telone reduced populations of the reniform nematode, thereby reducing the number of available hosts for reproduction of Pasteuria sp. There was a negative correlation between numbers of reniform nematodes and Pasteuria sp.: as the proportion of nematodes with attached spores increased, the numbers of reniform per volume of soil decreased, indicating that the bacterium may be suppressing the nematode population.<br /> (MS) A four year rotation system was developed and planted in 2009 using corn, cotton, soybean and peanut as alternate and non-hosts. All crops were grown to maturity and yields collected. Yields for continuous crops were lower in year two. <br /> <br /> (NC-Koenning) Soybean lines and cultivars with potential resistance derived from PI437564 were evaluated for yield and resistance to cyst nematode field trials located in three counties. Resistance to Races 1, 3, 9 and 14 were ineffective against SCN at these locations and lines with race 2 resistance had much greater yields. <br /> A soybean cultivar with resistance to races 1,2,3,5,9 and 14 was developed with resistance derived from Anand (Hartwig x Holiday) and will be released in 2011.<br /> <br /> (MN) Two field sites were established in Waseca and Lamberton, Minnesota, in 2003 and 2008, respectively, to determine the effect of different sequences of SCN-resistance sources (PI 887888, Peking, and PI437654) on dynamics of SCN population densities and their virulence phenotypes (races or HG Types). Waseca site was infested with initial population of SCN race 3, and the main aim of the experiment at this site was to determine how the cultivar sequences influence the changes of the SCN population from avirulent to virulent type on cultivars carrying certain resistance genes. At Lamberton site, the initial SCN population was race 1 that can overcome PI88788 resistance, and the main aim of the experiment at this site was to determine whether any cultivar sequence can change the population from virulent type to avirulent type or change to other HG Types so that the PI88788-source cultivars can be used. SCN population densities differed following different sequence of soybean cultivars, and susceptible soybean resulted in higher egg population density than resistant cultivars. Among the three SCN-resistant cultivars, the cultivar carrying PI88788 resistance supported highest SCN egg population density, the cultivar carrying Peking resistance intermediate, and cultivar carrying PI437654 resistance supported lowest SCN egg population density. Based on the data of HG Type analysis of the populations collected in 2007, 2008, and 2009, SCN populations selected by cultivar with PI 88788 source of resistance could overcome the resistance of PI 88788, and Peking-selected SCN population can overcome the resistance in Peking, not each other. In contrast, PI 437654 selected SCN population that could overcome both Peking and PI 88788 sources of resistance, although the population still had low reproduction potential on PI 437654.<br /> <br /> (SC) We finished a rotation study in which we followed the changes in genetic structure of a field population of reniform nematode. The rotations included: 1) cotton, corn, cotton, corn; 2) susceptible soybean, corn, susceptible soybean, corn; 3) resistant soybean, cotton, resistant soybean, cotton; 4) corn, cotton, corn, cotton; 5) continuous susceptible soybean; and 6) continuous cotton. Each crop was grown for a cycle of 120 days (total of 4 cycles for each rotation scheme) and DNA was extracted from 1,000 individuals for AFLP analysis after each cycle. The host plant exerted clear selection pressure and altered the predominant genotype. The most distinct effects were observed when resistant or susceptible soybean was used in a rotation scheme. Continuous cotton appeared to maintain the diversity of the genotype, but allowed for genetic drift from the original field genotype. Continuous soybean maintained the original field genotype for a longer period of time. These results suggest that the use of susceptible soybean as a host may be more useful for maintaining field genotype when culturing reniform nematodes in a greenhouse. <br /> <br /> (TX) Integrate resistant cultivars into management system. Have determined that temperature sensitive Mi gene resistance in tomato can be used successfully in west Africa if the nematode population is M arenaria, M. incognita, or M. javanica. RK- resistant peppers have limited use due to poor yield potential.<br /> <br /> (VA) A field survey of root-knot nematodes in tobacco has been initiated to evaluate the long-term effect of the RK1 gene on nematode species and race structure. We anticipate that the prolonged use of this gene to manage root-knot has caused a shift in the species and races from Meloidogyne incognita race 1 to M. incognita races 2 and 4 and to M. arenaria and M. javanica.<br /> <br /> <br /> Objective 2: Identify and incorporate new sources of resistance into elite germplams lines and cultivars. <br /> <br /> (AR) I am collaborating with Drs. Grover Shannon (Soybean Breeder) and Tri D. Vuong (Soybean Biotechnologist) on developing reniform molecular markers for reniform nematode resistance in soybean. We tested 190 lines in 2010 (5 reps each). I am conducting proprietary contract studies with Phytogen Seed Company looking for reniform resistance in cotton.<br /> <br /> <br /> (AL) Rotylenchulus reniformis (reniform nematode) can be a yield-limiting factor for upland cotton (Gossypium hirsutum L.). Resistance was discovered in a wild cotton relative, transferred to an upland background and released as the germplasm LONREN. We tested F2:4 lines from the cross LONREN-1 × Fibermax 966 in two fields, one infested with reniform nematode and one not infested. Twenty resistant lines and 20 susceptible lines were tested, with the objective of determining the effect of the LONREN resistance gene on yield, agronomic traits, and fiber quality in a nematode-infested and nematode-free environment. Lines with the LONREN resistance gene were stunted during early season growth and yielded less than their susceptible counterparts in the nematode-infested field. Nematode populations were reduced in plots where lines carrying the LONREN resistance gene were planted. There were no yield differences in the nematode-free field. Fiber quality was largely unaffected by the LONREN resistance gene, except that lines carrying the gene tended to have greater fiber strength.<br /> <br /> (GA) GA 120R1B3 is a non-commercial breeding line of cotton (Gossypium hirsutum L.) jointly released by the USDA Agricultural Research Service and the Agricultural Experiment Station at the University of Georgia in 2010. Greenhouse and field evaluations confirmed that GA 120R1B3 has a high level of resistance to Meloidogyne incognita (the southern root-knot nematode) and has high yield and excellent fiber quality characteristics. Field evaluations for yield and fiber quality were conducted both in fields infested with M. incognita and in fields without M. incognita. In the presence of the nematode, the resistance in GA 120R1B3 significantly reduces yield loss. The source of resistance in GA 120R1B3 was M-120 RNR. GA 120R1B3 has a level of resistance to M. incognita that is equivalent to that in M-120 RNR, but GA120R1B3 has significantly better lint percentage and fiber quality than M-120 RNR. GA 120R1B3 has yield and fiber quality generally comparable to commercial cultivars, and a lint percentage that was often greater than the commercial standards. GA 120R1B3 had good yield and excellent fiber quality in both the presence and absence of M. incognita.<br /> <br /> (MN) Several soybean lines carrying SCN-resistance different from the sources PI 88788 and Peking were used for breeding SCN-resistance cultivars. Crosses were made in 2009 and 2010 and the progenies of the crosses will be evaluated for SCN resistance.<br /> <br /> (MS) Twenty soybean varieties were evaluated for resistance to the root-knot nematode. Fourteen varieties were resistant and six moderately susceptible to the root-knot nematode. One hundred and twenty varieties were screened for resistance to the reniform nematode. Ten varieties were resistant, thirty-two varieties were moderately susceptible, seventeen varieties were susceptible and sixty-one varieties were highly susceptible.<br /> <br /> <br /> (NC-Davis) The roots of transgenic soybean plants engineered to express RNAi against three parasitism genes of soybean cyst nematode were analyzed for production of small RNAs to compare the actual transgene expression with observed levels of SCN resistance. Extremely low expression of RNAi constructs complementary to SCN parasitism genes that encode a mimic of plant CLE-like protein, an effector protein that interacts with plant spermidine synthase, and a novel SCN parasitism protein was observed in all transgenic soybean lines. Modifications of the RNAi vector used in soybean are currently in progress to improve transgene expression and resistance to SCN in soybean.<br /> <br /> (MS-Stetina) Efforts to incorporate useful levels of resistance to reniform nematode (Rotylenchulus reniformis) into upland cotton (Gossypium hirsutum) continued. Moderate levels of resistance from less-adapted day-neutral Texas race stock lines have been identified, and select lines will be tested in replicated trials in 2011 pending receipt of sufficient seed from the winter nursery in Tecoman, Mexico. In this project, we also are working to transfer high levels of reniform nematode resistance from five unique relatives of upland cotton (G. aridum, G. arboreum, G. longicalyx, G. barbadense, and G. herbaceum), and marker assisted selection is being used as appropriate to facilitate this effort. Molecular marker analysis indicated that we have BC4F2 plants with resistance from G. aridum, G. arboreum, or both sources combined. Continued testing and selection for desirable agronomic traits is anticipated for 2011 and 2012, with possible germplasm release(s) from this population in 2013. Collaborative work with cotton breeders at Mississippi State University resulted in F3 and F4 progeny with confirmed resistance from G. longicalyx (Lonren 1 and Lonren 2 sources of resistance) that show acceptable to excellent yield potential and fiber quality, including some that combine reniform nematode resistance with the nectariless trait. The Lonren 1 and Lonren 2 sources used as the resistance donors are being evaluated for suspected sensitivity to the herbicide fluometuron, though results to date indicate that neither is more sensitive than the commercial G. hirsutum cultivar used as a control. Evaluation of F2 progeny from a cross between plants with resistance from G. longicalyx (Lonren 2) and G. aridum (selected BC2F1 plants selected from a G. arboreum//G. hirsutum/G. aridum population) demonstrated that the resistance genes are not allelic and in some cases work together to result in greater suppression of the reniform nematode population. Resistance from G. barbadense accession GB 713 transferred to a G. hirsutum background by Dr. Forest Robinson (retired USDA, ARS, College Station, TX) has been crossed to materials adapted for Mississippi and the midsouthern U.S., including several nectariless lines, with progeny currently at the F3 generation. Accessions of G. herbaceum are being screened to identify novel sources of resistance for future germplasm development.<br /> <br /> Identification of reniform nematode resistance in advanced breeding lines and accessions from the soybean (Glycine max) germplasm collection was initiated. A total of 60 entries were screened to date based on female development on roots, and eight of these were selected for further testing to evaluate effects of nematode reproduction and confirm the resistant reaction. USDA ARS breeding line Glycine max DS-880 was released and has a moderate level of reniform nematode resistance. One parent of an existing population of 273 recombinant inbred lines was demonstrated to have a moderate level of resistance to reniform nematode in initial screenings, so an extensive phenotypic evaluation of the population was initiated to identify markers associated with resistance.<br /> <br /> (TX) New Sources of resistance. Have released two cotton breeding lines (Tam RKRNR 9 and Tam RKRNR 12) that have a high level of resistance to M. incognita and moderate resistance to R. reniformis, Have confirmed that five primitive G. hirsutum genotypes from Mexico represent unique sources of resistance to M. incognita and have initiated a backcross breeding program to introgress this resistance into modern cotton germplasm.<br /> <br /> <br /> Objective 3: Facilitate and improve identification of nematode species and races. <br /> (AR) My current student Marco Cordero and I are involved in the morphological and molecular taxonomy of the Criconemoidea, a widespread and often damaging nematode group of over a dozen genera. Included will be photographic records of all species studied and descriptions of several new species we have identified as there are several species we are in the process of describing that are new to science. I have been cooperating with a student at the University of Tabriz in Iran (Majid Pedram) on the identification and publication of new species in the virus vectoring genera Longidorus and Xiphinema and the description of new species in several other dorylime genera.<br /> (LA) The comparative reproduction and pathogenicity of isolates of Rotylenchulus reniformis from Alabama, Arkansas, Hawaii, Louisiana, Mississippi and Texas on cotton was evaluated in microplot trials. Prior to initiation of microplot trials, ten clonal populations of each geographic isolate were derived from single egg masses. Reproduction of the clonal populations of each geographic isolate were evaluated in greenhouse studies with Stoneville LA887 cotton by assessing the numbers of vermiform stages in soil and eggs per gram of root tissue 60 days after inoculation. On the basis of these trials, each repeated once, one clonal population of each of the six isolates was selected for use in microplot trials. Averaged over the two trials, clonal population designations selected for use in microplot trials and their respective reproduction values (R, where R=Pf/Pi) and numbers of eggs per gram of root were: AL-8 (R=14.9, eggs=202); AR-3 (R=30.4, eggs=525); HI-9 (R=20.2, eggs=183); LA-3 (R=18.2, eggs=517.); MS-7 (R=25.7, eggs=602) and TX-10 (R=42.8, eggs=938). Data from full-season (147 days) microplot trials, averaged over 2 years, showed significant differences (Tukeys HSD test (P< 0.05%)) among isolates of reniform nematode in both reproduction and pathogenicity. Dry plant weight at harvest averaged 370.6 g for the non-inoculated control. All isolates except the one from HI produced root weights at harvest that were reduced significantly below that of the control. Harvest weights for plants inoculated with LA-3 and MS-7 were significantly lower than those from the other four geographic regions.<br /> The comparative reproduction and pathogenicity of isolates of Rotylenchulus reniformis from Alabama, Arkansas, Hawaii, Louisiana, Mississippi and Texas on soybean was evaluated in microplot trials. Prior to initiation of microplot trials, ten clonal populations of each geographic isolate were derived from single egg masses. Reproduction of the clonal populations of each geographic isolate were evaluated in greenhouse studies with Deltapine 4331 soybean by assessing the numbers of vermiform stages in soil and eggs per gram of root tissue 60 days after inoculation. On the basis of these trials, each repeated once, one clonal population of each of the six isolates was selected for use in microplot trials. Averaged over the two trials, clonal population designations selected for use in microplot trials and their respective reproduction values (R, where R=Pf/Pi) and numbers of eggs per gram of root were: AL-7 (R=3.5, eggs=1,082); AR-4 (R=26.7, eggs=2,186); HI-1 (R=30.2, eggs=1,624); LA-3 (R=30.2, eggs=1,656); MS-2 (R=43.9, eggs=5,215) and TX-5 (R=55.4, eggs=4,329). <br /> Data from full-season (126 day) microplot trials, averaged over 2 years, showed significant differences (Tukeys HSD test (P< 0.05%)) among isolates of reniform nematode in both reproduction and pathogenicity. Dry plant weight at harvest averaged 273.3 g for the non-inoculated control. All isolates except the ones from HI and TX produced root weights at harvest that were reduced significantly below that of the control. With the exception of the MS-2 isolate, harvest weights for plants inoculated with AR-4 were significantly lower than those from the other four geographic regions. Relative to the control, numbers and dry weights of pods per plant at harvest were reduced significantly by all reniform iolates except those from AL and HI. <br /> <br /> (MS) A species specific primer pair (RrITS1) showed specificity to R. reniformis. RrITS1 generated amplicons on the 4 different populations of R. reniformis tested. The species-specific primer pair showed specificity in both the glasshouse and field populations. A positive diagnoses for a single vermiform reniform nematode could be detected from soil when using generating Ct values below 37. Two developmental phases of the syncytium were determined during soybean cyst parasitism. Syncytia undergoing resistant and susceptible reactions appear the same during early development. The resistance response is complete by 9 dpi. Using microdissection of the syncytia and neighboring cells identifed genes that characterize the resistance phase. The most highly induced pathways include jasmonic acid biosynthesis, 13-lipoxygenase pathway, S-adenosyl methionine pathway, phenylpropanoid biosynthesis, suberin biosynthesis, adenosylmethionine biosynthesis, ethylene biosynthesis from methionine, flavonoid biosynthesis and the methionine salvage pathway. These pathways, along with coumarin biosynthesis, cellulose biosynthesis and homogalacturonan degradation are induced. Custom pathway analyses implicate the jasmonic acid defense pathway as a factor involved in the resistant reaction of G. max.<br /> <br /> (SC) We developed 10 microsatellite loci appropriate to study the genetic diversity of reniform nematode. We included individuals from 15 geogrpahic locations and report data that supports a high inbreeding coefficient for this species. Interestingly, this high frequency of inbreeding resulting in a high frequency of homozygosity, occurs even with high level of genetic variation. The combination of high homozygosity and relatively high genetic variation suggest that studies examining the rates and patterns of shared versus fixed alleles between populations will be possible. Thus, these loci will be useful for studying reniform nematode population genetics<br /> <br /> (TX) Have adopted the PCR-based protocol of Adam et al. (2006) for the identification of M. marylandi.<br /> <br /> (VA) A new technique that uses an annular ring in the stage condenser produces images with increased resolution and enhanced surface morphology that are look like images produced with a scanning electron microscope. Annular rings increase resolution by making the illumination coherent (light waves that vibrate with constant phase relationships). The initial picture appears similar to a photographic negative, but is inverted into a positive with image processing software and a computer. This new technique of illumination increases the value of the observation of perineal patterns for identification of Meloidogyne species by increasing resolution and enhancing surface morphology.<br />

Publications

(ALABAMA) <br /> Castillo, J. D., Lawrence, K. S., Kloepper, J. W., and Van Santen, E. 2010. Evaluation of Drechslerella dactyloides, Drechslerella brochopaga, and Paecilomyces lilacinus for the biocontrol of Rotylenchulus reniformis. Nematropica 40:71-85.<br /> Sekora, N. S., K. S. Lawrence, P. Agudelo, E. van Santen, and J. A. McInroy. 2010. Differentiation of Meloidogyne species with FAME analysis. Nematropica 40:163-175.<br /> Castillo, J. D., Lawrence, K.S., Kloepper, J.W., and Van Santen, E. 2010. Evaluation of Drechslerella dactyloides, Drechslerella brochopaga, and Paecilomyces lilacinus for the biocontrol of Rotylenchulus reniformis. Nematropica 40:71-85.<br /> Moore, S. R., K. S. Lawrence, F. J. Arriaga, C. H. Burmester, E. van Santen. 2010. Natural movement of Rotylenchulus reniformis upon introduction into a no-till cotton system. Journal of Nematology 42: (Accepted Sept. 24, 2010).<br /> Castillo, J. D., Lawrence, K, Scott, T., and K. Glass. 2010. Isolation and molecular identification of Fusarium oxysporum isolates from cotton crops in Alabama. Proceedings of the Beltwide Cotton Conferences: 273-277.<br /> Castillo, J.D., Lawrence, K.S., Cruz, L.F., and K.M. Glass. 2010. Isolation and molecular identification of Fusarium oxysporum f. sp. vasinfectum race 2 present in Alabama cotton. Phytopathology 100:S21. American Phytopathological Society Meeting. Charlotte, NC. August 2010.<br /> Moore, S. R., W. S. Gazaway, K. S. Lawrence, B. Goodman, R. Akridge. 2010. Value of rotational crops for profit increase and reniform nematode suppression with and without a nematicide in Alabama. Proceedings of the Beltwide Cotton Conference, Vol. 1, 260 - 268. National Cotton Council of America, Memphis, TN. www.cotton.org/beltwide/proceedings.<br /> Moore, S. R., K. S. Lawrence, B. V. Ortiz, J. N. Shaw, J. Fulton. 2010. Evaluation of nematicides for the management of Rotylenchulus reniformis across management zones created using soil electrical conductivity. Phytopathology 100:S86.<br /> <br /> (ARKANSAS)<br /> Robbins, R.T., P. Chen, L. E. Jackson, E. E. Gbur, D. G. Dombek, E. Shipe, P. Arelli, G. Shannon, and C. Overstreet. 2010. Reniform Nematode Reproduction on Soybean Cultivars and Breeding Lines in 2009. New Orleans, LA 2010. Proceedings of the Beltwide Cotton Conferences Pgs. 190-199.<br /> Ye, Weimin and R.T Robbins. 2010. Morphology and Taxonomy of Xiphinema (Nematoda: Longidoridae) Occurring in Arkansas, USA. Acta Agriculturae Universitatis Jianxiensis 32:928-945.<br /> Pedram M., G. Niknam, M. T. Vinciguerra, W. Ye and R. T. Robbins. 2010. Morphological and molecular characterisation of Paractinolaimus sahandi n. sp. (Nematoda: Actinolaimidae)from Sahand Mountains in Iran. Journal of Helminthology doi:10.1017/ S0022149X10000556 First view article<br /> Pedram, M., G.Niknam, R. T. Robbins, W. Decraemer, W. Ye and Y. Qing . 2010. First record of Trichodorus primitivus (de Man, 1880) Micoletzky, 1922 and morphological and molecular identification of Longidorus elongatus (de Man, 1876) Micoletzky, 1922 from Canada. Plant Disease (Disease notes) 94:782<br /> Pourjam, E,. M. Pedram, M. T. Vinciguerra, and R. T. Robbins. 2010. 2010.Enchodelus decraemerae n. sp and Enchodorus dolichurus Vinciguerra, 1976 (Dorylaimida: Nordiidae), two rare species from Iran. Russian Journal of Nematology (In Press)<br /> Niknam,G., M. Pedram, E. G. Nejad, W. Ye, R. T. Robbins and Z.T. Maafi. 2010. Morphological and molecular characterization of Longidorus tabrizicus n. sp. and L. sturhani Rubtsova, Subbotin, Brown and Moens, 2001 (Nematoda: Longidoridae) from north-western Iran. Russian Journal of Nematology (In Press).<br /> (GEORGIA)<br /> Timper, P., R.F. Davis, T.M. Webster, T.B. Brenneman, S.L.F Meyer, I.A. Zasada, C.P. Rice. 2010. Response of root-knot nematodes and Palmer amaranth to tillage and rye green manure. Agronomy Journal. Accepted.<br /> Nagy, E.D., Y. Chu, Y. Guo, S. Khanal, S. Tang, Y. Li, W.B. Dong, P. Timper, C. Taylor, P. Ozias-Akins, C.C. Holbrook Jr, V. Beilinson, N.C. Nielsen, H. Stalker, S.J. Knapp. 2010. Recombination is suppressed in an alien introgression on chromosome 5A of peanut harboring Rma, a dominant root-knot nematode resistance gene. Molecular Breeding 26:357-370.<br /> Timper, P. 2009. Population dynamics of Meloidogyne arenaria and Pasteuria penetrans in a long-term crop rotation study. Journal of Nematology 41:291-299.<br /> Timper, P., D. Koné, J. Yin, P. Ji, and B.B. McSpadden Gardener. 2009. Evaluation of an antibiotic-producing strain of Pseudomonas fluorescens for suppression of plant-parasitic nematodes. Journal of Nematology 41:234-240.<br /> Davis, R. F., and R. C. Kemerait. 2009. The multi-year effects of repeatedly growing cotton with moderate resistance to Meloidogyne incognita. Journal of Nematology 41:140-145.<br /> Lu, P., R. F. Davis, and R. C. Kemerait. 2010. Effect of mowing cotton stalks and preventing plant re-growth on post-harvest reproduction of Meloidogyne incognita. Journal of Nematology (in press). <br /> Shen, X.,Y. He, E. L. Lubbers, R. F. Davis, R. L. Nichols, and P. W. Chee. 2010. Fine mapping QMi-C11 a major QTL controlling root-knot nematodes resistance in Upland cotton. Theoretical and Applied Genetics (in press).<br /> Davis, R. F., P. W. Chee, E. L. Lubbers, and O. L. May. 2010. Registration of GA 120R1B3 germplasm line of cotton. Journal of Plant Registrations (in press).<br /> (LOUISIANA) <br /> Navas, A., P. Flores-Romero, S. Sanchez-Moreno, J.A. Camargo and E.C. McGawley. 2010. Effects of Heavy Metal Soil Pollution on Nematode Communities After the Aznalcollar Mining Spill. Nematropica 40(1):13-30.<br /> McGawley, E. C., M. J. Pontif, and C. Overstreet. 2010. Variation in reproduction and pathogenicity of geographic Isolates of Rotylenchulus reniformis on cotton. Nematropica 40: 275-288.<br /> <br /> McGawley, E. C., C. Overstreet, and M. J. Pontif. 2010. Variation in reproduction and pathogenicity of geographic Isolates of Rotylenchulus reniformis on soybean. Nematropica: 41(1): accepted. in press.<br /> McGawley, E.C. and C. Overstreet. 2010 Reniform Nematode, In: Compendium of Soybean Diseases. American Phytopathological Society. (In press). <br /> McGawley, E. C., M. J. Pontif, and C. Overstreet. 2010. Introduction to Nematodes: a Multimedia Presentation. <http://www.ontaweb.org/><br /> Overstreet, C, E.C. McGawley, C. Hollier, D. Ferrin and S.Raghuwinder. Current Strategies for Sampling Plant Parasitic Nematodes in Field Crops. Louisiana Plant Pathology Disease Identification and Management Series.<br /> (MISSISSIPPI, USDA) <br /> Stetina, S. R., Molin, W. T., and Pettigrew, W. T. 2010. Effects of varying planting dates and tillage systems on reniform nematode and browntop millet populations in cotton. Online. Plant Health Progress doi:10.1094/PHP-2010-1227-01-RS.<br /> Hewlett, T. E., Stetina, S. R., and Schmidt, L.M. 2010. Rate of germination and growth of in vitro produced Pasteuria spp. parasitizing Rotylenchulus reniformis. Journal of Nematology (Abstr.) (in press)<br /> Smith, J. R., Arelli, P. R., Gillen, A., Young, L. D., Stetina, S. R., Mengistu, A., Ray, J. D., and Koenning, S. 2010. Notice of release of soybean germplasm line DS-880 with resistance to multiple races of soybean cyst nematode and high yield potential. USDA ARS Docket Number P.0021.10.<br /> Arias de Ares, R. S., Stetina, S. R., Tonos, J. L., Scheffler, J. A., and Scheffler, B.E. 2010. Microsatellites reveal genetic diversity in reniform nematode populations. P. 204 in Proceedings of the Beltwide Cotton Conferences, New Orleans, LA, January 4-7, 2010. (Abstr.)<br /> (MISSISSIPPI) <br /> Klink V.P., P.D. Matsye, and G.W. Lawrence. 2010. Developmental genomics of the resistant reaction of soybean to the soybean cyst nematode. Modern Concepts in Functional Genomics Chapter 10, Pgs. 249  270. Plant Tissue Culture and Applied Plant Biotechnology.<br /> Doshi, R. A., King, R. L., and Lawrence, G. W. 2010. Classification of Rotylenchulus reniformis numbers in cotton using remotely sensed hyperspectral data on self-organized maps. Journal of Nematology : (accepted) <br /> T V.P. Klink, G.W. Lawrence, P.D. Matsye , and K.C. Showmaker . 2010. The application of a developmental genomics approach to study the resistance reaction of soybean to the soybean cyst nematode. Nematropica 40: 1-11.<br /> <br /> (MINNESOTA)<br /> Chen, S., Potter, B., and Orf, J. 2010. Virulence of the soybean cyst nematode has increased over years in Minnesota. Journal of Nematology 42:in press. (Abstr.)<br /> <br /> (NORTH CAROLINA) <br /> Wang, J., Lee, C., Replogle, A., Joshi, S., Korkin, D., Hussey, R. S., Baum, T.J., Davis, E.L., Wang, X., and Mitchum, M.G. 2010. Dual roles for the variable domain in protein trafficking and host-specific recognition of Heterodera glycines CLE effector proteins. New Phytologist 187:1003-1017.<br /> Hewezi, T., P. Howe, T.R. Maier, R.S. Hussey, M.G. Mitchum, E.L. Davis, and T.J. Baum. 2010. Arabidopsis spermidine synthase is targeted by an effector protein of the cyst nematode Heterodera schachtii. Plant Physiology 152:968-984.<br /> Wang, J., Replogle, A., Hussey, R. S., Baum, T.J., Wang, X., Davis, E.L., and Mitchum. M.G. 2010. Identification of potential host plant mimics of CLV3/ESR (CLE)-like peptides from the plant parasitic nematode Heteroders schachtii. Molecular Plant Pathology: DOI: 10.1111/J.13643703.2010.00660.X<br /> Koenning, S. R., and Wrather, J. A. 2010. Suppression of soybean yield potential in the Continental United States by plant diseases from 2006 to 2009. Plant Health Progress doi:10.1094-2010-1122-01-RS.<br /> <br /> (SOUTH CAROLINA) <br /> Leach, M., P. Agudelo, A.L. Lawton-Rauh. 2010. Ten Polymorphic Microsatellites for Reniform Nematode, Rotylenchulus reniformis. Molecular Ecology Resources (doi: 10.1111/j.1755-0998.2010.02970.x)<br /> <br /> (VIRGINIA) <br /> Eisenback, J. D. 2010. A new technique for photographing perineal patterns of root-knot nematodes. Journal of Nematology 42:33-34.<br /> J. M. Charchar, M. E. N. Fonseca, J. B. Pinheiro L. S. Boiteux, and J. D. Eisenback. 2010. Epidemics of Meloidogyne brasilensis in Central Brazil on processing tomato hybrids that have the root-knot nematode Mi resistance gene. Plant Disease 94:781.<br /> Venkatesan Parkunan, Charles S. Johnson, and Jon D. Eisenback. 2010. Effects of Php Gene-Associated versus Induced Resistance to Tobacco Cyst Nematode in Flue-Cured Tobacco. Journal of Nematology 42:261-266<br /> Venkatesan Parkunan, Charles S. Johnson, and Leach, M., P. Agudelo, A.L. Lawton-Rauh. 2010. Ten Polymorphic Microsatellites for Reniform Nematode, Rotylenchulus reniformis. Molecular Ecology Resources (doi: 10.1111/j.1755-0998.2010.02970.x). 2009. Biological and Chemical Induction of Resistance to the Tobacco Cyst Nematode in Oriental and Flue-Cured Tobacco. Journal of Nematology 41:203-210. <br /> João M. Charchar, Jonathan D. Eisenback, Jairo V. Vieira, Maria Esther de N. Foncesca-Boiteux, and Leonardo S. Boiteux. 2009. Meloidogyne polycephannulata n. sp. (Nematoda: Meloidogynidae), a root-knot nematode parasitizing carrot in Brazil. Journal of Nematology 41:174-186.<br />

Impact Statements

1. Developed 10 microsatellite loci appropriate to study the genetic diversity of reniform nematode.
2. Custom pathway analyses implicate the jasmonic acid defense pathway as a factor involved in the resistant reaction of Glycine max to Heterodera glycines.
3. First in U.S.A. to demonstrate reproductive and pathological differences in geographic populations of Rotylenchulus reniformis on soybean and cotton.
4. Modifications of the RNAi vector used in soybean are currently in progress to improve transgene expression and resistance to SCN in soybean.
5. A soybean cultivar with resistance to races 1,2,3,5,9 and 14 was developed with resistance derived from Anand (Hartwig x Holiday) and will be released in 2011.
6. A field survey of root-knot nematodes in tobacco has been initiated to evaluate the long-term effect of the RK1 gene on nematode species and race structure. We anticipate that the prolonged use of this gene to manage root-knot has caused a shift in the species and races from Meloidogyne incognita race 1 to M. incognita races 2 and 4 and to M. arenaria and M. javanica.
7. Released two cotton breeding lines (Tam RKRNR 9 and Tam RKRNR 12) that have a high level of resistance to M. incognita and moderate resistance to R. reniformis

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Report Information

Participants

P. Agudelo (SC)
S. Chen (MN)
R. Davis (GA)
D. Dickson (FL)
K. Lawrence (AL)
G. Lawrence (MS)
E. McGawley (LA)
C. Overstreet (LA)
R. Robbins (AR)
J. Starr (TX)
R. Lacewell (Administrative Advisor, TX).

Visiting Students: Claudia Holguin (SC), Addison Plaisance (LA), Deborah Xavier (LA)

Brief Summary of Minutes

The S-1046 meeting was convened at 9:00 AM in the Orlando World Center Marriott in Orlando, FL on January 7, 2011. Scientists in attendance (and their state designation) were: P. Agudelo (SC), S. Chen (MN) R. Davis (GA), D. Dickson (FL), K. Lawrence (AL), G. Lawrence (MS), E. McGawley (LA), C. Overstreet (LA), R. Robbins (AR) and J. Starr (TX). R. Lacewell (Administrative Advisor, TX).
S. Stetina (MS) absent but report provided.
Students present and their study directors:
Claudia Holguin (SC  P. Agudelo)
Addison Plaisance (LA  E. McGawley)
Deborah Xavier (_LA  C. Overstreet)

Each member was asked to introduce themselves for all members and tell their affiliations with their respective universities or USDA-ARS employment. Afterward budget and departmental updates were discussed amongst the members present.
The minutes from the 2010 meeting were accepted and approved. Starr (TX) provided the motion to accept the minutes and received a second by K. Lawrence (AL). Ron Lacewell (Administrative Advisor, TX) provided the committee information on our project status and made comments from his standpoint as the administrative advisor to the group. Dr. Lacewell congratulated the members related to getting enthusiasm back into the team. The research members are actively working together to solve issues for agriculture including the horticulture industry.
It was emphasized to include new members and check with previous members that have not attended to determine if they were going to continue with the project. Several scientists were mentioned to contact for future attendance. Funding and budget concerns were discussed.
Members present then provided oral state reports.
At the business meeting it was stressed to provide bullet points and accomplishments to the secretary (G. Lawrence, MS) as soon as possible in order to get the final report complete and approved. It was proposed by K. Lawrence (AL) that we meet with members of the W-2186 Multi-State group in 2011. After a brief discussion, Starr (TX) provide the motion to accept this meeting and was seconded by McGawley (LA). The motion passed and K. Lawrence (AL) chair of W-2186 and G. Lawrence (MS) chair of S-1046 will work out the details to have a combined meeting in 2012. Meeting locations were discussed and possible meeting dates. It was proposed to meet in November similar to meeting dates that were held previously. Dickson (FL) will check for the meeting date of the Methyl Bromide conference so there would be no conflicts.
In other discussions G. Lawrence (MS) will serve as chair the 2012 annual meeting and P. Agudelo (SC) will serve as secretary.
The group then planned to meet at 6:00 for a group dinner
The 2011 annual meeting of the S-1046 Multistate Research Project was adjourned at 4:05 pm.

Accomplishments

Objective 1: Integrate resistant cultivars with other nematode management tactics to reduce selection pressure on nematode populations and communities. <br /> Soybean: (AR) One hundred forty seven soybean varieties new to the Arkansas Soybean Variety Testing program and 134 breeding lines and varieties from Southern Public Soybean Breeders for examined for resistance to the reniform nematode (Rotylenchulus reniformis) in soybean (68 from Arkansas; 21 from Clemson; 16 from Missouri; 4 from USDA, Jackson, TN; 1 from Virginia Tech and 24 from Southern Illinois - Carbondale). Progeny 5191, Delta Grow DG5252R3Y, JTN-5203 were similar to the resistant checks Forrest, Anand and Hartwig. These may be useful in a cotton-soybean rotation to reduce numbers of reniform nematode and allow cotton to be grown economically.<br /> In 2003 on the effects of rotation of soybeans with 3 different soybean resistance sources (mode of resistance) to the soybean cyst nematode at the Pine Tree Experiment Station, St. Francis county. The ninth year of the rotation is completed. When rotations are compared the nematode numbers are least when Anand is the variety planted. A study rotating 3 Roundup Ready varieties with different resistance reactions has completed its sixth year at Pine Tree. A bio-control agent has become prevalent in this test and has been converted to a biocontrol of soybean cyst nematode study.<br /> (LA) Comparative reproduction and pathogenicity of isolates of Rotylenchulus reniformis from Alabama, Arkansas, Hawaii, Louisiana, Mississippi and Texas on soybean was evaluated in microplot trials. Prior to initiation of microplot trials, ten populations of each geographic isolate were derived. Reproduction of the single egg-mass (SEM) populations of each geographic isolate were evaluated in greenhouse studies with Deltapine 4331 soybean by assessing the numbers of vermiform stages in soil and eggs per gram of root tissue 60 days after inoculation. On the basis of these trials, each repeated once, one SEM population of each of the six isolates was selected for use in microplot trials. Averaged over the two trials, SEM populations selected for use in microplot trials and their respective reproduction values (R, where R = Pf/Pi) and numbers of eggs per gram of root were: AL-7 (R = 3.5, eggs = 1,082); AR-4 (R = 26.7, eggs = 2,186); HI-1 (R = 30.2, eggs = 1,624); LA-3 (R = 30.2, eggs = 1,656); MS-2 (R = 43.9, eggs = 5,215) and TX-5 (R = 55.4, eggs = 4,329). Data from full-season (126 day) microplot trials, averaged over 2 years, showed significant differences (Tukeys HSD test (P d 0.05%)) among isolates of reniform nematode in both reproduction and pathogenicity.<br /> (MN) A long-term field plot studies in Minnesota demonstrated that that SCN populations selected by cultivar with PI 88788 source of resistance can only overcome the resistance of PI 88788 not the Peking and PI 437654; Peking-selected SCN populations can overcome the resistance in Peking, not PI 88788 and PI 437654; and PI 437654 can select SCN populations to overcome both sources of resistance PI 88788 and Peking. <br /> <br /> (MS) Statina Identification of reniform nematode resistance in advanced breeding lines and accessions from the soybean (Glycine max) germplasm collection continued. Lines not previously reported as being resistant that were identified as moderately resistant or resistant in our initial screenings were advanced to longer trials in which reniform nematode reproduction is measured. The final run of this experiment to confirm the phenotype and provide additional insight into the level of resistance in each line is in progress. A full report on this work is tentatively scheduled for presentation at the Southern Soybean Disease Workers annual meeting in March 2012. One parent of an existing population of 273 recombinant inbred lines was demonstrated to have a moderate level of resistance to reniform nematode in initial screenings, so an extensive phenotypic evaluation of the population is underway to identify markers associated with resistance.<br /> <br /> Cotton: (AL) A trial to reduce the risk of damage to cotton by Rotylenchulus reniformis was conducted in a 26 ha field in south Alabama in 2009 - 2011. The field was delineated into three management zones using soil electrical conductivity (EC) and elevation, the nematicides 1, 3-dichloropropene, aldicarb, oxamyl and abamectin were applied alone and in various combinations within each zone with an untreated control. Population densities of R. reniformis prior to nematicide treatment were 535, 1096 and 71 vermiform life stages/150cm3 of soil for zones 1, 2 and 3, respectively. Zones 1, 2 and 3 averaged increasing volumetric water content (P < 0.1) of 0.138, 0.150 and 0.184/cm3, throughout the season. Evaluation of the interaction of R. reniformis population and soil moisture on cotton yields indicate that the driest zone, Zone 1, was at the highest risk of yield loss and benefitted with yield gains (P< 0.1) from higher rates of nematicides. Although Zone 1 supported only half the initial R. reniformis population compared with Zone 2, the combination of soil moisture and nematode stress in Zone 1 resulted in a larger yield increase over the untreated control. Zone 2 with the highest initial nematode populations and adequate soils moisture did not benefit from the nematicide with a yield increase as neither did Zone 3 with low nematode numbers and good soil moisture. The factor of water availability throughout the growing season should be considered in risk assessment when creating site-specific management zones for Rotylenchulus reniformis.<br /> <br /> Cotton cultivars occupying the largest acreage of Alabama were examined for susceptibility to Fusarium wilt (FW); subsequently fungal isolates were collected to confirm Fusarium oxysporum f. sp. vasinfectum (FOV) presence. Symptoms of FW were initially observed in mid-June and increased in severity through July and August. FW incidence culminated with 16% of the Rowden and < 1% of the resistant control M-315 plants dying, respectively. FOV was isolated on APDA from hypocotyls regions of all cotton cultivars except PHY367WRF, ST5458B2RF, and M-315. The numbers of root-knot nematodes increase in all the cotton varieties. The standard susceptible cotton, Rowden, averaged 2149 root-knot eggs per gram of root while the M-315 resistant cotton supported only 88 eggs per gram of root. All cotton cultivars supported higher populations of root-knot (P > 0.001) as compared to M-315 except PHY 367 WRF. This PHY 367 WRF was also the only cultivar less susceptible to the nematode as compared to the Rowden susceptible control. Seed cotton yield varied from a low of 1151 lb/A in the susceptible Rowden to a high of 4467 lb/A in the PHY 367 WRF plots. The PHY 367 WRF, PHY 565 WRF, ST 4288 B2RF, and ST 5458 B2RF cultivars all produced more cotton (P > 0.05) as compared to Rowden. All of the cotton cultivars produced yields similar to the resistant cotton M-315 except Deltapine DP 0949 B2RF. Genetic analysis of each FOV isolate, by cotton variety, was characterized by partial sequences of the translational elongation factor (EF-1±) gene, indicating very diverse clades of genotypes within this Alabama field. Combined analysis conducted in AL and in CA (Rebecca Bennett) identified genotype races 1, 4, 8, and several undefined genotypes to be present. Results of this field test indicate resistance to FW does exist in our commercial cotton cultivars, and FOV in Alabama appears to be extremely diverse genetically. Further greenhouse tests to confirm isolate pathogenicity found none of the races produced root necrosis without the nematode present.<br /> <br /> (GA) Timper  Davis Nematodes are among the leading cause of yield loss in cotton in the US. In greenhouse studies in Georgia, infection of cotton by the cotton root-knot nematode (Meloidogyne incognita) or the reniform nematode (Rotylenchulus reniformis) induced a plant defense response known as systemic acquired resistance (SAR). Increased levels of P-peroxidase, G-peroxidase, and catalase are associated with the induction of SAR, and the levels of these enzymes were significantly increased compared to untreated plants. Application of a chemical analog of salicylic acid known to induce SAR in some plants caused the greatest increases. SAR induced by R. reniformis reduced the root galling caused by subsequent infection with M. incognita by 33 to 36% and reproduction of M. incognita by 35 to 45%. SAR induced by M. incognita infection reduced reproduction of R. reniformis by 18 to 26%.<br /> <br /> Winter cover crops increase organic matter in soil. Some fungal pathogens of nematodes may be able to utilize this organic matter as an alternative food source. We hypothesized that NemOut (Paecilomyces lilacinus) would provide greater control of Meloidogyne incognita in cotton when a winter cover crop has been grown compared to winter fallow. In a greenhouse experiment, we showed that growing a rye cover crop and leaving the residue on the soil surface resulted in greater percentage suppression of the nematode by P. lilacinus in the succeeding cotton crop than leaving the soil fallow (62% with rye vs 36% with fallow).<br /> <br /> (MS) Stetina Efforts to incorporate useful levels of resistance to reniform nematode (Rotylenchulus reniformis) into upland cotton (Gossypium hirsutum) continued. Moderate levels of resistance from less-adapted day-neutral Texas race stock lines were tested in replicated trials in 2011; three lines were selected for advanced testing in 2012. In this project, we also are working to transfer high levels of reniform nematode resistance from five unique relatives of upland cotton (G. aridum, G. arboreum, G. longicalyx, G. barbadense, and G. herbaceum), and marker assisted selection is being used as appropriate to facilitate this effort. Molecular marker analysis indicated that we have BC4F3 plants with resistance from G. aridum, G. arboreum, or both sources combined. Continued testing and selection for desirable agronomic traits is anticipated for 2012, with possible germplasm release(s) from this population in 2013. Collaborative work with cotton breeders at Mississippi State University resulted in F4 and F5 progeny with confirmed resistance from G. longicalyx (Lonren 1 and Lonren 2 sources of resistance) that show acceptable to excellent yield potential and fiber quality, including some that combine reniform nematode resistance with the nectariless trait. The Lonren 1 and Lonren 2 sources used as the resistance donors were found to be no more sensitive to the herbicide fluometuron than commercial G. hirsutum cultivars. Seed increases of advanced generation materials with moderate resistance from G. hirsutum or resistance from G. barbadense were completed in 2011 in anticipation of replicated plot tests in 2012. Resistance from G. barbadense accession GB 713 transferred to a G. hirsutum background by Dr. Forest Robinson (retired USDA, ARS, College Station, TX) has been crossed to materials adapted for Mississippi and the midsouthern U.S., including several nectariless lines, with several populations currently at the F4 and F5 generations. Approximately 1,500 accessions of G. arboreum and 90 accessions of G. herbaceum were planted in the field in 2011, and single plants were agronomically characterized and self pollinated to represent each accession in subsequent resistance screening and associated germplasm development research. We considered this a necessary first step in identifying novel sources of resistance for future germplasm development, as many of the accessions showed considerable segregation for agronomic traits such as leaf shape, plant height, and flowering.<br /> <br /> (MS) Lawrence A four year rotation system was developed and planted in 2009 using corn, cotton, soybean and peanut as alternate and non-hosts. All crops were grown to maturity and yields collected. Yields for some of the rotation crops were low in 2009 due to delays in harvest from inclement weather. In 2010 crops yields were good. In the plots that were planted with the same crop in consecutive years, yields were lower. The data analysis of harvest for year four 2011produced similar results.<br /> <br /> (MS) Lawrence Nematode Detection Service - A web service is currently being developed in which the end user can upload ground or sub-orbital hyperspectral reflectances of their fields and see the results of the prediction models in an easy to use interface which is graphically appealing. The inclusion of a web service to this project increases the commerciality of this project<br /> <br /> Vegetables: (FL) Tomato cultivars with the Mi-1 gene are under investigation as an alternative to using fumigant nematicides. Evaluations of Amelia, Crista, and Red Bounty included fumigated and nonfumigated treatments and in both spring and autumn trials compared with a root-knot nematode susceptible tomato cultivar. <br /> <br /> Objective 2: Identify and incorporate new sources of resistance into elite germplams lines and cultivars. <br /> Soybean: (AR) In collaborating with Drs. Grover Shannon (Soybean Breeder) and Tri D. Vuong (Soybean Biotechnologist) on developing reniform molecular markers for reniform nematode resistance in soybean, 190 lines in 2010 (5 reps each). Also proprietary contract studies with Phytogen Seed Company looking for reniform resistance in cotton are in progress.<br /> (MN) Soybean germplasms with resistance different from the common sources of resistance PI 88788 and Peking were identified, and a few lines were used in breeding SCN-resistant cultivars. Four SCN-resistance QTLs in the soybean line PI 567516C were determined, including two significant QTLs and two suggestive QTLs in PI 567516C. The two significant QTLs were detected on chromosome 10 and chromosome 19, and the SNP markers associated with the two QTLs may be useful in marker-assisted selection. <br /> <br /> (MS) Lawrence Soybean Cyst Nematode Race 15 or now 2? Soybean varieties submitted for inclusion in the Mississippi variety evaluation trials are examined in the greenhouse for possible resistance to the root-knot, reniform and soybean cyst nematodes. Testing for 2011 has started with the soybean cyst nematode host race 15. One hundred soybean varieties have currently been examined and sixty additional varieties have been inoculated are in progress in the greenhouse. All varieties have been susceptible to this Mississippi SCN population.<br /> <br /> Corn: (MS) Lawrence Eighty-two corn hybrids were examined in the greenhouse for root-knot nematode resistance. All hybrids were susceptible with a reproductive factor ranging from Rf 10.4  149.9. <br /> <br /> Cotton: (AL) In 2011, we tested F2:4 lines from the cross LONREN-1 × Fibermax 966 in two adjacent cotton fields of the same soil type, one was infested with reniform nematode and one was not infested. Twenty resistant lines and 20 susceptible lines were tested, with the objective of determining the effect of the LONREN resistance gene on yield, agronomic traits, and fiber quality in a nematode-infested and nematode-free environment. Cotton lines with the LONREN resistance gene were severely stunted and yielded less than their susceptible counterparts in the nematode-infested field. Nematode populations were reduced in plots where lines carrying the LONREN resistance gene were planted. There were no yield differences in the nematode-free field. Fiber quality was largely unaffected by the LONREN resistance gene, except that lines carrying the gene tended to have greater fiber strength.<br /> <br /> (MS) Stetina Members of this regional project agreed to initiate a coordinated testing effort to identify host plant resistance to reniform nematode (Rotylenchulus reniformis) in cotton (Gossypium hirsutum) and soybean (Glycine max). The first step in this process is to select genetically unique populations of reniform nematode for coordinated testing. During 2011, members of this project team and cooperators in Hawaii sent 10 individual adult female reniform nematodes from their respective research collections to Dr. Stetinas lab in Stoneville, MS. Research collections from Mississippi (S. Stetina and G. Lawrence), Alabama (K. Lawrence), Georgia (R. Davis), South Carolina (P. Agudelo), and Hawaii (B. Sipes) are represented. DNA extraction and amplification from most of these samples is complete, with the last set of materials to be processed by the end of January 2012. During spring 2012, molecular markers developed in a previous study will be applied to the samples to assess the genetic diversity among these research collections. By summer of 2012, we should be able to select diverse populations for use in screening cotton and soybean germplasm for reaction to reniform nematode. Coordinated testing of advanced germplasm could begin as soon as fall 2012.<br /> <br /> <br /> <br /> <br /> (TX) Have collaborated with USDA researchers in the development of BARBREN-713, an upland cotton genotype with resistance to root-knot and reniform nematodes. This material will be officially released in 2012. <br /> Have advance three breeding lines with unique sources of reistance to root-knot nematodes to the BC2F2 generation<br /> <br /> Objective 3: Facilitate and improve identification of nematode species and races. <br /> (AR) With Marco Cordero, we are investigating the morphological and molecular taxonomy of the Criconemoidea, a widespread and often damaging nematode group of over a dozen genera. Included will be photographic records of all species studied and descriptions of several new species we have identified as there are several species we are in the process of describing that are new to science. The first of 5 chapters has been submitted for publication and 2 more chapters are almost ready for submission. During 2011 a species of Cyst nematode, Heterodera urticae previously found only in Europe was found and reported.<br /> <br /> (MS) G. Lawrence/ Klink/K. Lawrence Molecular diagnostic tests have been developed and utilized to diagnose and to confirm Rotylenchulus sp. in Mississippi soils. DNA primers and probes were developed for a TaqMan probe quantitative PCR (qPCR)-based assay. The qPCR procedure could accurately detect the presence of Rotylenchulus sp. with a strong correlation (R² = 0.9924) between the morphologically (visually) observed number of number of soil extracted R. reniformis and the qPCR estimated number of nematodes from metagenomic DNA isolated from the same soil sample.<br /> <br /> (SC) Research includes studying the distribution and population density of Hoplolaimus species in soybean and cotton fields in South Carolina. Our objective is also to identify ecological and management factors potentially correlated to the presence of specific species of lance nematodes, and to develop molecular diagnostic methods to identify the main species of lance<br /> nematodes. <br /> <br /> (TX) Have adopted the PCR-based protocol of Adam et al. (2006) for the identification of M. marylandi.<br />

Publications

(Alabama)<br /> Book Chapters:<br /> Lawrence, K. S. and G. W. Lawrence. 2011. Chapter 14: Pest Management: Nematodes.In Conservation Tillage Systems: Production, Profitability and Stewardship. eds Bergtold, J. , Raper, R. , Hawkins, G., and Iversen, K. CRC Press LLC. (in review). <br /> <br /> Journal Articles:<br /> Moore, S. R., K. S. Lawrence, F. J. Arriaga, E. van Santen, C. H. Burmester. 2011. Influence of water infiltration and root growth on the downward dispersion of Rotylenchulus reniformis. Nematropica 42:1 73-79.<br /> <br /> Sikkens, R. B., D. B. Weaver, K. S. Lawrence, S. R. Moore, and E. van Santen. 2011. LONREN upland cotton germplasm response to Rotylenchulus reniformis inoculation level. Nematropica 41:66-72.<br /> <br /> Castillo, J. D., and Lawrence, K. S. 2011. First report of Catenaria auxiliaris parasitizing the reniform nematode Rotylenchulus reniformis on cotton in Alabama. Plant Disease 95(4):490 (http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-07-10-0524?journalCode=pdis).<br /> <br /> Moore, S. R., K. S. Lawrence, F. J. Arriaga, C. H. Burmester, E. van Santen. 2010. Natural movement of Rotylenchulus reniformis upon introduction into a no-till cotton system. Journal of Nematology 42:4 307-312.<br /> <br /> Castillo, J. D., K. S. Lawrence, J. W. Kloepper, and E. V. Santen. 2010. Evaluation of Drechslerella dactyloides, Drechslerella brochopaga, and Paecilomyces lilacinus for biocontrol of Rotylenchulus reniformis. Nematripica 40:71-85.<br /> <br /> Castillo, J. D., K. S. Lawrence, G. Morgan-Jones, C. A. Ramirez. 2010. Identification of fungi associated with Rotylenchulus reniformis. Journal of Nematology 42:313-318.<br /> <br /> Peer reviewed:<br /> Moore, S. R., K. S. Lawrence, S. Nightengale. 2011. Evaluation of cotton seed treatments for the control of root-knot nematode and Fusarium wilt on cotton, 2010.Report No. 5:N011 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Moore, S. R., K. S. Lawrence, B. E. Norris. 2011. Evaluation of experimental nematicides for the control of reniform nematodes on cotton in north Alabama, 2010. Report No. 5:N010 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Moore, S. R., K. S. Lawrence, J. R. Akridge. 2011. Evaluation of experimental nematicides for the control of reniform nematodes on cotton in south Alabama, 2010. Report No. 5:N009 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Moore, S. R., K. S. Lawrence, B. E. Norris. 2011. Evaluation of experimental nematicides for the control of reniform nematode on soybean in north Alabama, 2010.Report No. 5:N008 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Moore, S. R., K. S. Lawrence, B. E. Norris. 2011. Evaluation of seed treatment fungicides for the control of seedling disease on cotton in north Alabama, 2010. Report No. 5:ST020 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence, K. S., S. R. Moore, W. S. Gazaway, G. W. Lawrence, J. R. Akridge. 2011. Evaluation of cotton varieties with TeloneII for reniform management in cotton in south Alabama, 2010.Report No. 5:N006 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence, K. S., S. R. Moore, G. W. Lawrence, C. H. Burmester, C. Norris. 2011. Evaluation of seed treatments and seed quality in cotton seedling disease management in Alabama, 2010. Report No. 5:ST022 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence, K. S., S. R. Moore, G. W. Lawrence, C. H. Burmester, C. Norris. 2011. Evaluation of experimental seed treatments in cotton seedling disease management in Alabama, 2010.Report No. 5:ST021 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Scott,Tamara Z., K. S. Lawrence, K. Glass. 2010. Cotton resistance to Root-knot and Fusarium wilt in Alabama, 2010. Report No. 4:ST014 DOI: 10.1094/PDMR04. The American Phytopathological Society, St. Paul, MN<br /> <br /> Abstracts:<br /> Lawrence, K. S., G. W. Lawrence, V. Klink, and S. Moore. 2011. Host status of soybean differential genotypes to Rotylenchulus reniformis and Meloidogyne incognita race 3. Phytopathology 101:S99.<br /> <br /> Moore, S. R., K. S. Lawrence, B. Ortiz, J. Shaw, J. Fulton. 2011. Evaluation of the effects of soil moisture on the damage potential of Rotylenchulus reniformis on cotton. Phytopathology 101:S123<br /> <br /> Schrimsher, D. W., K. S. Lawrence, J. Castillo, S. R. Moore, J. W. Kloepper. 2011. Effects of Bacillus firmus GB-126 on the soybean cyst nematode mobility in vitro. Phytopathology 101:S161. <br /> <br /> Castillo, J. D., Lawrence, K. S.,and J. W. Kloepper. 2011. Evaluation of Bacillus firmus seed treatment for the biocontrol of reniform nematode Rotylenchulus reniformis on cotton plants. Phytopathology 101:S29. <br /> <br /> Proceedings: <br /> Moore, S. R., K. S. Lawrence. 2011. Effects of soil type on the reproductive potential of Rotylenchulus reniformis on cotton. Proceedings of the Beltwide Cotton Conference, Vol. 1, 235 - 240.National Cotton Council of America, Memphis, TN.www.cotton.org/beltwide/proceedings.<br /> <br /> Sikkens, R. B., S. R. Moore, K. S. Lawrence, T. Wu, D. B. Weaver. 2011. LONREN germplasm response to nematode inoculation level. Proceedings of the Beltwide Cotton Conference, Vol. 1, 728 - 736.National Cotton Council of America, Memphis, TN.www.cotton.org/beltwide/proceedings.<br /> <br /> Weaver, D. B., R. B. Sikkens, S. R. Moore, K. S. Lawrence, R. Sharpe. 2011. LONREN x FM966 progeny evaluation in a field infested with reniform nematode. Proceedings of the Beltwide Cotton Conference, Vol. 1, 737 - 741.National Cotton Council of America, Memphis, TN.www.cotton.org/beltwide/proceedings.<br /> <br /> Scott, Tamara Z., K.S. Lawrence, K. Glass, J.D. Castillo. 2011. Fusarium wilt Identification and Root-Knot Nematode Effects on Commercial Cotton Cultivars in 2010. Proceedings of the Beltwide Cotton Conference, Vol. 1, 224  229. National Cotton Council of America, Atlanta, GA. www.cotton.org/beltwide/proceedings.<br /> <br /> Castillo, J.D., Lawrence, K.S.,and J.W. Kloepper. 2011. Evaluation of Bacillus firmus (Votivo®) Paecilomyces lilacinus strain 251 for the biocontrol of reniform nematode Rotylenchulus reniformis. Proceedings of the Beltwide Cotton Conference, Vol. 1, 242 - 246.National Cotton Council of America, Memphis, TN.www.cotton.org/beltwide/proceedings.<br /> <br /> Ballard, B. B. K. S. Lawrence, E. J. Sikora, and J. F. Murphy. Initial response of soybean mosaic virus, bean pod mottle virus and Rotylenchulus reniformis on soybean.Proceedings of the Beltwide Cotton Conference, Vol. 1, 219 - 223. National Cotton Council of America, Memphis, TN.www.cotton.org/beltwide/proceedings.<br /> <br /> Lawrence, G.W. K.S. Lawrence and B. Haygood. 2011. Efficacy of Dow AgroSciences seed treatment fungicide STP 20143 for the management of the seedling disease complex of cotton. Proceedings of the National Beltwide Cotton Conference, Vol. 1, National cotton Council, Memphis TN. Online: www.cotton.org/beltwide/proceedings. <br /> <br /> Bennett, R.S., A.L. Bell, J.E. Woodward, K.S. Lawrence, C.S. Rothrock, T.L. Kirkpatrick, G.W. Lawrence, P.D. Colyer, and R.M. Davis. 2011. Report progress on a contemporary survey of the Fusarium wilt fungus in the United States. Proceedings of the National Beltwide Cotton Conference, Vol. 1, National cotton Council, Memphis TN. Online: www.cotton.org/beltwide/proceedings.<br /> <br /> <br /> (Arkansas)<br /> Journal Articles:<br /> Chen, P., T. Ishibashi, C. H. Sneller, J. C. Rupe, D. G. Dombek, R. T. Robbins, and R. D. Riggs. 2011. Registration of UA 4910 Soybean. Journal of Plant Registrations, Vol. 5, No. 1, January 2011. <br /> <br /> Chen, P., T. Ishibashi, C. H. Sneller, J. C. Rupe, D. G. Dombek, and R. T. Robbins. 2011. Registration of R991613F, R012731F, and R013474F Soybean Germplasm Lines with Diverse Pedigrees. Journal of Plant Registrations, Vol. 5, No. 2, May 2011.<br /> <br /> Robbins, R. T., E. Shipe, P. Arelli, P. Chen, G. Shannon, K. M. Rainey, L. E. Jackson, E. E. Gbur, D. G. Dombek, & J. T. Velie. 2011. Reniform nematode reproduction on soybean cultivars and breeding lines in 2010. Proceeding of the 2011 Beltwide Cotton Conferences, Atlanta, Georgia, January 4-7, 2011, Pgs. 167-174.<br /> <br /> <br /> Abstracts:<br /> J.G. Shannon, J. A. Wrather, M.A. Woolard, S.L. Smothers, S.M. Pathan, H.T. Nguyen, and R.T. Robbins. 2011. 805-11482- a high yielding soybean with resistance to multiple diseases and nematode species. Proceeding of the Southern Soybean Disease Workers. Fort Walton Beach FL.<br /> <br /> Robbins, R. T., and L. E. Jackson. 2011. Soybean Varieties and Breeding Lines Shown With Resistance to Reniform Nematode in Greenhouse Tests, 1998-2010. Proceeding of the Southern Soybean Disease Workers. Fort Walton Beach FL.<br /> <br /> Robbins, R. T., E. Shipe, P. Arelli, P. Chen, G. Shannon, K. M. Rainey, L. E. Jackson, E. E. Gbur, D. G. Dombek, and J. T. Velie. 2011. Reniform Nematode Reproduction on Soybean Cultivars and Breeding Lines in 2010. Proceedings of the Beltwide Cotton Conferences, Atlanta.<br /> <br /> Robbins, Robert T., and W. Ye. 2011. Heterodera urticae, Cooper 1955, a Heterodera goettingiana-group cyst nematode found in Arkansas. <br /> <br /> Cordero, M., R. T. Robbins, and A. L. Szalanski. 2011. Phylogenetic relathionships among nematodes of the suborder criconematina using ITS-1 rdna region. <br /> <br /> (Georgia)<br /> Aryal, S. K., R. F. Davis, K. L. Stevenson, P. Timper, and P. Ji. 2011. Induction of systemic acquired resistance by Rotylenchulus reniformis and Meloidogyne incognita in cotton following separate and concomitant inoculations. Journal of Nematology: 43: (in press)<br /> <br /> Aryal, S. K., R. F. Davis, K. L. Stevenson, P. Timper, and P. Ji. 2011. Influence of infection of cotton by Rotylenchulus reniformis and Meloidogyne incognita on the production of enzymes involved in systemic acquired resistance. Journal of Nematology: 43: (in press)<br /> <br /> <br /> (Louisiana) <br /> McGawley, E.C.; C. Overstreet, and M.J. Pontif. 2011. Variation in reproduction and pathogenicity of geographic isolates of Rotylenchulus reniformis on soybean. Nematropica: 41: 12-22. <br /> <br /> (Minnesota)<br /> Zheng, J. W., and S. Y. Chen. 2011. Estimation of virulence type and level of soybean cyst nematode field populations in response to resistant cultivars. Journal of Entomology and Nematology 3:37-43. <br /> <br /> Lian, L., F. Wang, R. Denny, P. Schaus, N. Young, J. Orf, and S. Chen. 2011. Identifying novel sources of resistance to the soybean cyst nematod. Abstracts of 1st Annual National Association of Plant Breeders Meeting. Http://www.plantbreeding.org/napb/Meetings/2011/Abstracts11e05dsSJ.pd: 28.<br /> <br /> (Mississippi) Statina <br /> Schmidt, L. M., Hewlett, T. E., Green, A., Simmons, L. J., Kelley, K., Doroh, M., and Stetina, S. R. 2010. Molecular and morphological characterization and biological control capabilities of a Pasteuria ssp. parasitizing Rotylenchulus reniformis, the reniform nematode. Journal of Nematology 42:207-217.<br /> <br /> Fang, D. D. and Stetina, S. R. 2011. Improving cotton (Gossypium hirsutum L.) plant resistance to reniform nematodes by pyramiding Ren1 and Ren2. Plant Breeding 130:673-678.<br /> <br /> Arias, R. S., Stetina, S. R., and Scheffler, B. E. 2011. Comparison of whole-genome amplications for microsatellite genotyping of Rotylenchulus reniformis. Electronic Journal of Biotechnology. DOI: 10.2225/vol14-issue3-fulltext-13.<br /> <br /> (Mississippi) Lawrence<br /> Book Chapters:<br /> Lawrence, K. S. and G. W. Lawrence. 2009. Chapter 14: Pest Management: Nematodes.In Conservation Tillage Systems: Production, Profitability and Stewardship. eds Bergtold, J. , Raper, R. , Hawkins, G., and Iversen, K. CRC Press LLC. (in review). <br /> <br /> Klink V.P., P.D. Matsye, and G.W. Lawrence. 2010. Cell-specific studies of soybean resistance to its major pathogen, the soybean cyst nematode as revealed by laser capture micro-dissection, gene pathway analyses and functional studies. Soybean. Intech Publishers. Pp 1-32.<br /> <br /> Journal Articles:<br /> Doshi, R. A., King, R. L., and Lawrence, G. W. 2011. Classification of Rotylenchulus reniformis numbers in cotton using remotely sensed hyperspectral data on self-organized maps. Journal of Nematology 42 179-193. <br /> <br /> Kurt Showmaker, Gary W. Lawrence, Shien Lu, Clarissa Balbaian and Vincent P. Klink. 2011. Quantitative field testing Rotylenchulus reniformis DNA from metagenomic samples isolated directly from soil. PLoS ONE 6(12) e28954. Doi:10.1371/journal.pone.0028954. <br /> <br /> Proceedings:<br /> <br /> Lawrence, G.W. K.S. Lawrence and B Haygood. 2011. Efficacy of Dow AgroSciences seed treatment fungicide STP 20143 for the management of the seedling disease complex of cotton. Proceedings of the National Beltwide Cotton Conference, Vol. 1, National cotton Council, Memphis TN. Online: www.cotton.org/beltwide/proceedings. <br /> <br /> Lawrence, K.S., G.W. Lawrence and S.R. Moore. 2011. New nematicide potentials in cotton in the southeast and mid south. Proceedings of the National Beltwide Cotton Conference, Vol. 1, National cotton Council, Memphis TN. Online: www.cotton.org/beltwide/proceedings. <br /> <br /> Bennett, R.S., A.L. Bell, J.E. Woodward, K.S. Lawrence, C.S. Rothrock, T.L. Kirkpatrick, G.W. Lawrence, P.D. Colyer, and R.M. Davis. 2011. Report progress on a contemporary survey of the Fusarium wilt fungus in the United States. Proceedings of the National Beltwide Cotton Conference, Vol. 1, National cotton Council, Memphis TN. Online: www.cotton.org/beltwide/proceedings. <br /> <br /> Abstracts & Others:<br /> Lawrence, K. S., G. W. Lawrence, V. Klink, and S. Moore. 2011. Host<br /> status of soybean differential genotypes to Rotylenchulus reniformis and<br /> Meloidogyne incognita race 3. Phytopathology 101:S99.<br /> <br /> Lawrence, K. S., S. R. Moore, W. S. Gazaway, G. W. Lawrence, J. R.<br /> Akridge. 2011. Evaluation of cotton varieties with TeloneII for reniform<br /> management in cotton in south Alabama, 2010.Report No. 5:N006 DOI:<br /> 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence, K. S., S. R. Moore, G. W. Lawrence, C. H. Burmester, C.<br /> Norris. 2011. Evaluation of seed treatments and seed quality in cotton<br /> seedling disease management in Alabama, 2010. Report No. 5:ST022 DOI:<br /> 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence, K. S., S. R. Moore, G. W. Lawrence, C. H. Burmester, C.<br /> Norris. 2011. Evaluation of experimental seed treatments in cotton<br /> seedling disease management in Alabama, 2010.Report No. 5:ST021 DOI:<br /> 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN<br /> <br /> (South Carolina)<br /> Leach, M.M., P. Agudelo, A.L. Lawton-Rauh. 2011. Genetic Variability of Rotylenchulus reniformis. Plant Disease 96:24-29. <br /> <br /> Ma, X., P. Agudelo, J.D. Mueller, and H.T. Knap. 2011. Molecular Characterization and Phylogenetic Analysis of Hoplolaimus stephanus. Journal of Nematology 43:25-34.<br /> <br /> Leach, M.M., P. Agudelo, A.L. Lawton-Rauh. 2011. Effect of Crop Rotations on Population Structure of Reniform Nematode, Rotylenchulus reniformis. Plant Disease 96:30-36. <br /> <br /> Agudelo, P., S.A. Lewis, B.A. Fortnum. 2011. Validation of a Real-time PCR Assay for the Identification of Meloidogyne arenaria. Plant Disease 95: 835-838.<br /> <br />

Impact Statements

1. Soybean-cotton rotations will continue to be the most economical means of nematode control until resistance is found in cotton.
2. Rotations have an environmental advantage over chemical nematicides by having no long lasting effect on the field or crop and is environmentally safe to use.
3. We identified cotton varieties resistance to Meloidogyne incognita are available to our growers. Resistant varieties also a less susceptible to Fusarium wilt.
4. Precision nematicide application can enhance cotton yield when the field is infested with Rotylenchulus reniformis.
5. Moisture stress potential is as important as initial nematode populations when selecting and applying nematicides.
6. There is a lack of consistence in fruit yield of the resistant cultivars when grown in nonfumigated soil even though galling indicies were consistent very low.
7. The low percentage galling of resistant tomato cultivars vs. susceptible cultivars indicates that the root-knot nematode resistant Mi-1 gene in tomato was not broken by soil temperature under polyethylene films.
8. Root- systemic acquired resistance (SAR) against nematodes in cotton could be induced by applying a chemical analog of salicylic acid. SAR may contribute significantly to reducing the damage in cotton caused by nematodes.
9. Research at LSU during this period was the first in the U.S. to document variation in reproduction and pathogenicity among geographic isolates of the reniform nematode, Rotylenchulus reniformis on soybean.
10. In 2010, research from the LSU AgCenter was also the first to document similar reproductive and pathogenic variation in reniform populations on cotton.
11. The host response of the crops used in our studies for resistance or susceptibility to plant-parasitic nematodes demonstrates the importance of continual variety examinations. There is a lack of resistance to the root-knot nematodes in corn hybrids currently available. With soybean there are indications that the introduction or shift of a SCN race will upset the resistance available to this specific race. We recovered a population of SCN identified as SCN race 15. In earlier studies after screening over 300 varieties found none to be resistant to this population. In examining recently developed varieties, resistance appears to be lacking.
12. Rotations with non-host crops will continue to be a major role in nematode management even with resistant varieties.
13. Nematode Detection Service - a web based service for nematode detection will allow the end-user to upload from ground data and see their results graphically.
14. A molecular diagnostic technique for the reniform nematode will increase the accuracy of detecting the presence and quantification of this pest in the soil.
15. Soil samples are processed from South Carolina planted with soybean, cotton, and turf. We have identified Hoplolaimus galeatus and H. stephanus associated with turf and H. columbus associated with soybean and cotton. We have validated molecular methods for their identification.
16. In South Carolina, the Columbia Lance Nematode is found in 21% of soybean samples (124/600) and 59% of cotton samples (237/400), with densities ranging from 10 to 330 nematodes per 100 cc of soil.
17. In North Carolina, lance nematodes are found in only 10% of soybean fields, specifically in samples from Robeson, Scotland, Bertie, Camden, Pasquotank, Tyrell, Washington and Beaufort counties. The densities ranged from 10 to 70 nematodes per 100 cc of soil. Interestingly, none of these were identified as Columbia Lance Nematode. All of the species found were H.galeatus-like.
18. Additional samples from other southeastern states are included and have found Hoplolaimus magnistylus in Arkansas and Tennessee.
19. Collaborated with USDA researchers in the development of BARBREN-713, an upland cotton genotype with resistance to root-knot and reniform nematodes will be officially released in 2012.
20. dvance three breeding lines with unique sources of resistance to root-knot nematodes to the BC2F2 generation

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Report Information

Participants

Agudelo, Paula (pagudel@clemson.edu) - Clemson South Carolina;
Chen, Senyu (chenx099@umn.edu) - U. of Minnesota;
Dickson, Don (dwd@ufl.edu) - U. of Florida;
Eisenback, Jon (Jon@vt.edu) - Virginia Tech;
Robbins, Bob, (Jon@vt.edu) - U. of Arkansas;
Starr, Jim (j-starr@tamu.edu) - Texas A&M AgriLife;
Lacewell, (r-lacewell@tamu.edu) - Texas A&M AgriLife;
Thompson, David (dathomps@nmsu.edu) - New Mexico State;
McGawley, Ed (emcgawley@agcenter.lsu.edu) - LSU;
Lawrence, Kathy (lawrekk@auburn.edu) - Auburn;
Lawrence, Gray (glawrence@entomology.msstate.edu) - Miss. State U.

Brief Summary of Minutes

This was a joint meeting with the Western Regional Research Project (W-2186) group, organized by Kathy Lawrence (AL) and Gary Lawrence (MS).

November 1, 2012:
The meeting was convened at 8:15 a.m. in the Mississippi Coastal Research and Extension Center in Biloxi, MS. Members of the W-2186 group were also in attendance. USDA members were unable to travel to participate in this years meeting.
Started with oral reports by members of W-2186. Ron Lacewell commented on this being a good joint meeting, and warned about potential large cuts in funding for agricultural research. He emphasized the importance of interactions between states for this project and suggested adding more members. David Thompson added that it is important not to overlap objectives between multi-state projects.
Oral reports for S-1046 were presented as follows: Charles Overstreet (LA- reniform nematode on cotton), Don Dickson (FL- root-knot nematodes on tomato and peanut), Ed McGawley (LA-reniform nematode on cotton), Vince Klink (MS- soybean cyst nematode), Jim Starr (TX- root-knot nematodes on peanut and cotton), Jon Eisenback (VA- root-knot nematodes), Paula Agudelo (SC  lance nematodes), Robert Robbins (AR-soybean cyst and reniform nematodes).

November 2, 2012:
Oral reports by members of W-2186 continued. Final S-1046 report was presented: Senyu Chen (Minnesota; SCN population dynamics). Then, graduate students from Auburn University and Mississippi State University gave progress reports on their research (7 presentations).
Business meeting:
Called to order at 11:30 a.m. Jim Starr moved to approve minutes from previous meeting. Steve Thomas seconded and all agreed. Minutes were approved as distributed by e-mail.
The next meeting will be in Clemson, South Carolina in November of 2013. The dates will be decided soon. Paula Agudelo (incoming President) will communicate with members for planning. Graduate student presentations will be encouraged at this meeting.
Jon Eisenback (incoming Secretary) will plan the meeting in 2014 in Williamsburg, Virginia.
Potential new members were discussed. Travis Faske from University and Arkansas and Chuck Johnson from Virginia Tech will be invited to join.
Jim Starr requested that formal thanks for the sailing excursion organized by Kathy and Gary be included in the minutes. All agreed in that this was an extraordinary experience.
Meeting adjourned.

Accomplishments

Objective 1: Integrate resistant cultivars with other nematode management tactics to reduce selection pressure on nematode populations and communities. <br /> Soybean: <br /> (AR) One hundred forty seven soybean varieties new to the Arkansas Soybean Variety Testing program and 134 breeding lines and varieties from Southern Public Soybean Breeders for examined for resistance to the reniform nematode (Rotylenchulus reniformis) in soybean (68 from Arkansas; 21 from Clemson; 16 from Missouri; 4 from USDA, Jackson, TN; 1 from Virginia Tech and 24 from Southern Illinois - Carbondale). Progeny 5191, Delta Grow DG5252R3Y, JTN-5203 were similar to the resistant checks Forrest, Anand and Hartwig. These may be useful in a cotton-soybean rotation to reduce numbers of reniform nematode and allow cotton to be grown economically.<br /> In 2003 on the effects of rotation of soybeans with 3 different soybean resistance sources (mode of resistance) to the soybean cyst nematode at the Pine Tree Experiment Station, St. Francis county. The ninth year of the <br /> rotation is completed. When rotations are compared the nematode numbers are least when Anand is the variety planted. A study rotating 3 Roundup Ready varieties with different resistance reactions has completed its sixth year at Pine Tree. A bio-control agent has become prevalent in this test and has been converted to a biocontrol of soybean cyst nematode study.<br /> <br /> (LA) Comparative reproduction and pathogenicity of isolates of Rotylenchulus reniformis from Alabama, Arkansas, Hawaii, Louisiana, Mississippi and Texas on soybean was evaluated in microplot trials. Prior to initiation of microplot trials, ten populations of each geographic isolate were derived. Reproduction of the single egg-mass (SEM) populations of each geographic isolate were evaluated in greenhouse studies with Deltapine 4331 soybean by assessing the numbers of vermiform stages in soil and eggs per gram of root tissue 60 days after inoculation. On the basis of these trials, each repeated once, one SEM population of each of the six isolates was selected for use in microplot trials. Averaged over the two trials, SEM populations selected for use in microplot trials and their respective reproduction values (R, where R = Pf/Pi) and numbers of eggs per gram of root were: AL-7 (R = 3.5, eggs = 1,082); AR-4 (R = 26.7, eggs = 2,186); HI-1 (R = 30.2, eggs = 1,624); LA-3 (R = 30.2, eggs = 1,656); MS-2 (R = 43.9, eggs = 5,215) and TX-5 (R = 55.4, eggs = 4,329). Data from full-season (126 day) microplot trials, averaged over 2 years, showed significant differences (Tukeys HSD test (P d 0.05%)) among isolates of reniform nematode in both reproduction and pathogenicity.<br /> <br /> (MN) A long-term field plot studies in Minnesota demonstrated that that SCN populations selected by cultivar with PI 88788 source of resistance can only overcome the resistance of PI 88788 not the Peking and PI 437654; Peking-selected SCN populations can overcome the resistance in Peking, not PI 88788 and PI 437654; and PI 437654 can select SCN populations to overcome both sources of resistance PI 88788 and Peking. <br /> <br /> (MS) Statina Identification of reniform nematode resistance in advanced breeding lines and accessions from the soybean (Glycine max) germplasm collection continued. Lines not previously reported as being resistant that were identified as moderately resistant or resistant in our initial screenings were advanced to longer trials in which reniform nematode reproduction is measured. The final run of this experiment to confirm the phenotype and provide additional insight into the level of resistance in each line is in progress. A full report on this work is tentatively scheduled for presentation at the Southern Soybean Disease Workers annual meeting in March 2012. One parent of an existing population of 273 recombinant inbred lines was demonstrated to have a moderate level of resistance to reniform nematode in initial screenings, so an extensive phenotypic evaluation of the population is underway to identify markers associated with resistance.<br /> <br /> Cotton: <br /> (AL) A trial to reduce the risk of damage to cotton by Rotylenchulus reniformis was conducted in a 26 ha field in south Alabama in 2009 - 2011. The field was delineated into three management zones using soil electrical conductivity (EC) and elevation, the nematicides 1, 3-dichloropropene, aldicarb, oxamyl and abamectin were applied alone and in various combinations within each zone with an untreated control. Population densities of R. reniformis prior to nematicide treatment were 535, 1096 and 71 vermiform life stages/150cm3 of soil for zones 1, 2 and 3, respectively. Zones 1, 2 and 3 averaged increasing volumetric water content (P < 0.1) of 0.138, 0.150 and 0.184/cm3, throughout the season. Evaluation of the interaction of R. reniformis population and soil moisture on cotton yields indicate that the driest zone, Zone 1, was at the highest risk of yield loss and benefitted with yield gains (P< 0.1) from higher rates of nematicides. Although Zone 1 supported only half the initial R. reniformis population compared with Zone 2, the combination of soil moisture and nematode stress in Zone 1 resulted in a larger yield increase over the untreated control. Zone 2 with the highest initial nematode populations and adequate soils moisture did not benefit from the nematicide with a yield increase as neither did Zone 3 with low nematode numbers and good soil moisture. The factor of water availability throughout the growing season should be considered in risk assessment when creating site-specific management zones for Rotylenchulus reniformis.<br /> <br /> Cotton cultivars occupying the largest acreage of Alabama were examined for susceptibility to Fusarium wilt (FW); subsequently fungal isolates were collected to confirm Fusarium oxysporum f. sp. vasinfectum (FOV) presence. Symptoms of FW were initially observed in mid-June and increased in severity through July and August. FW incidence culminated with 16% of the Rowden and < 1% of the resistant control M-315 plants dying, respectively. FOV was isolated on APDA from hypocotyls regions of all cotton cultivars except PHY367WRF, ST5458B2RF, and M-315. The numbers of root-knot nematodes increase in all the cotton varieties. The standard susceptible cotton, Rowden, averaged 2149 root-knot eggs per gram of root while the M-315 resistant cotton supported only 88 eggs per gram of root. All cotton cultivars supported higher populations of root-knot (P > 0.001) as compared to M-315 except PHY 367 WRF. This PHY 367 WRF was also the only cultivar less susceptible to the nematode as compared to the Rowden susceptible control. Seed cotton yield varied from a low of 1151 lb/A in the susceptible Rowden to a high of 4467 lb/A in the PHY 367 WRF plots. The PHY 367 WRF, PHY 565 WRF, ST 4288 B2RF, and ST 5458 B2RF cultivars all produced more cotton (P > 0.05) as compared to Rowden. All of the cotton cultivars produced yields similar to the resistant cotton M-315 except Deltapine DP 0949 B2RF. Genetic analysis of each FOV isolate, by cotton variety, was characterized by partial sequences of the translational elongation factor (EF-1±) gene, indicating very diverse clades of genotypes within this Alabama field. Combined analysis conducted in AL and in CA (Rebecca Bennett) identified genotype races 1, 4, 8, and several undefined genotypes to be present. Results of this field test indicate resistance to FW does exist in our commercial cotton cultivars, and FOV in Alabama appears to be extremely diverse genetically. Further greenhouse tests to confirm isolate pathogenicity found none of the races produced root necrosis without the nematode present.<br /> <br /> (GA) Timper  Davis Nematodes are among the leading cause of yield loss in cotton in the US. In greenhouse studies in Georgia, infection of cotton by the cotton root-knot nematode (Meloidogyne incognita) or the reniform nematode (Rotylenchulus reniformis) induced a plant defense response known as systemic acquired resistance (SAR). Increased levels of P-peroxidase, G-peroxidase, and catalase are associated with the induction of SAR, and the levels of these enzymes were significantly increased compared to untreated plants. Application of a chemical analog of salicylic acid known to induce SAR in some plants caused the greatest increases. SAR induced by R. reniformis reduced the root galling caused by subsequent infection with M. incognita by 33 to 36% and reproduction of M. incognita by 35 to 45%. SAR induced by M. incognita infection reduced reproduction of R. reniformis by 18 to 26%.<br /> <br /> Winter cover crops increase organic matter in soil. Some fungal pathogens of nematodes may be able to utilize this organic matter as an alternative food source. We hypothesized that NemOut (Paecilomyces lilacinus) would provide greater control of Meloidogyne incognita in cotton when a winter cover crop has been grown compared to winter fallow. In a greenhouse experiment, we showed that growing a rye cover crop and leaving the residue on the soil surface resulted in greater percentage suppression of the nematode by P. lilacinus in the succeeding cotton crop than leaving the soil fallow (62% with rye vs 36% with fallow).<br /> <br /> (MS) Stetina Efforts to incorporate useful levels of resistance to reniform nematode (Rotylenchulus reniformis) into upland cotton (Gossypium hirsutum) continued. Moderate levels of resistance from less-adapted day-neutral Texas race stock lines were tested in replicated trials in 2011; three lines were selected for advanced testing in 2012. In this project, we also are working to transfer high levels of reniform nematode resistance from five unique relatives of upland cotton (G. aridum, G. arboreum, G. longicalyx, G. barbadense, and G. herbaceum), and marker assisted selection is being used as appropriate to facilitate this effort. Molecular marker analysis indicated that we have BC4F3 plants with resistance from G. aridum, G. arboreum, or both sources combined. Continued testing and selection for desirable agronomic traits is anticipated for 2012, with possible germplasm release(s) from this population in 2013. Collaborative work with cotton breeders at Mississippi State University resulted in F4 and F5 progeny with confirmed resistance from G. longicalyx (Lonren 1 and Lonren 2 sources of resistance) that show acceptable to excellent yield potential and fiber quality, including some that combine reniform nematode resistance with the nectariless trait. The Lonren 1 and Lonren 2 sources used as the resistance donors were found to be no more sensitive to the herbicide fluometuron than commercial G. hirsutum cultivars. Seed increases of advanced generation materials with moderate resistance from G. hirsutum or resistance from G. barbadense were completed in 2011 in anticipation of replicated plot tests in 2012. Resistance from G. barbadense accession GB 713 transferred to a G. hirsutum background by Dr. Forest Robinson (retired USDA, ARS, College Station, TX) has been crossed to materials adapted for Mississippi and the midsouthern U.S., including several nectariless lines, with several populations currently at the F4 and F5 generations. Approximately 1,500 accessions of G. arboreum and 90 accessions of G. herbaceum were planted in the field in 2011, and single plants were agronomically characterized and self pollinated to represent each accession in subsequent resistance screening and associated germplasm development research. We considered this a necessary first step in identifying novel sources of resistance for future germplasm development, as many of the accessions showed considerable segregation for agronomic traits such as leaf shape, plant height, and flowering.<br /> <br /> (MS) Lawrence A four year rotation system was developed and planted in 2009 using corn, cotton, soybean and peanut as alternate and non-hosts. All crops were grown to maturity and yields collected. Yields for some of the rotation crops were low in 2009 due to delays in harvest from inclement weather. In 2010 crops yields were good. In the plots that were planted with the same crop in consecutive years, yields were lower. The data analysis of harvest for year four 2011produced similar results.<br /> <br /> (MS) Lawrence Nematode Detection Service - A web service is currently being developed in which the end user can upload ground or sub-orbital hyperspectral reflectances of their fields and see the results of the prediction models in an easy to use interface which is graphically appealing. The inclusion of a web service to this project increases the commerciality of this project<br /> <br /> Vegetables: <br /> (FL) Tomato cultivars with the Mi-1 gene are under investigation as an alternative to using fumigant nematicides. Evaluations of Amelia, Crista, and Red Bounty included fumigated and nonfumigated treatments and in both spring and autumn trials compared with a root-knot nematode susceptible tomato cultivar. <br /> <br /> Objective 2: Identify and incorporate new sources of resistance into elite germplams lines and cultivars. <br /> Soybean: <br /> (AR) In collaborating with Drs. Grover Shannon (Soybean Breeder) and Tri D. Vuong (Soybean Biotechnologist) on developing reniform molecular markers for reniform nematode resistance in soybean, 190 lines in 2010 (5 reps each). Also proprietary contract studies with Phytogen Seed Company looking for reniform resistance in cotton are in progress.<br /> <br /> (MN) Soybean germplasms with resistance different from the common sources of resistance PI 88788 and Peking were identified, and a few lines were used in breeding SCN-resistant cultivars. Four SCN-resistance QTLs in the soybean line PI 567516C were determined, including two significant QTLs and two suggestive QTLs in PI 567516C. The two significant QTLs were detected on chromosome 10 and chromosome 19, and the SNP markers associated with the two QTLs may be useful in marker-assisted selection. <br /> <br /> (MS) Lawrence Soybean Cyst Nematode Race 15 or now 2? Soybean varieties submitted for inclusion in the Mississippi variety evaluation trials are examined in the greenhouse for possible resistance to the root-knot, reniform and soybean cyst nematodes. Testing for 2011 has started with the soybean cyst nematode host race 15. One hundred soybean varieties have currently been examined and sixty additional varieties have been inoculated are in progress in the greenhouse. All varieties have been susceptible to this Mississippi SCN population.<br /> <br /> Corn: <br /> (MS) Lawrence Eighty-two corn hybrids were examined in the greenhouse for root-knot nematode resistance. All hybrids were susceptible with a reproductive factor ranging from Rf 10.4  149.9. <br /> <br /> Cotton: <br /> (AL) In 2011, we tested F2:4 lines from the cross LONREN-1 × Fibermax 966 in two adjacent cotton fields of the same soil type, one was infested with reniform nematode and one was not infested. Twenty resistant lines and 20 susceptible lines were tested, with the objective of determining the effect of the LONREN resistance gene on yield, agronomic traits, and fiber quality in a nematode-infested and nematode-free environment. Cotton lines with the LONREN resistance gene were severely stunted and yielded less than their susceptible counterparts in the nematode-infested field. Nematode populations were reduced in plots where lines carrying the LONREN resistance gene were planted. There were no yield differences in the nematode-free field. Fiber quality was largely unaffected by the LONREN resistance gene, except that lines carrying the gene tended to have greater fiber strength.<br /> <br /> (MS) Stetina Members of this regional project agreed to initiate a coordinated testing effort to identify host plant resistance to reniform nematode (Rotylenchulus reniformis) in cotton (Gossypium hirsutum) and soybean (Glycine max). The first step in this process is to select genetically unique populations of reniform nematode for coordinated testing. During 2011, members of this project team and cooperators in Hawaii sent 10 individual adult female reniform nematodes from their respective research collections to Dr. Stetinas lab in Stoneville, MS. Research collections from Mississippi (S. Stetina and G. Lawrence), Alabama (K. Lawrence), Georgia (R. Davis), South Carolina (P. Agudelo), and Hawaii (B. Sipes) are represented. DNA extraction and amplification from most of these samples is complete, with the last set of materials to be processed by the end of January 2012. During spring 2012, molecular markers developed in a previous study will be applied to the samples to assess the genetic diversity among these research collections. By summer of 2012, we should be able to select diverse populations for use in screening cotton and soybean germplasm for reaction to reniform nematode. Coordinated testing of advanced germplasm could begin as soon as fall 2012.<br /> <br /> (TX) Have collaborated with USDA researchers in the development of BARBREN-713, an upland cotton genotype with resistance to root-knot and reniform nematodes. This material will be officially released in 2012. <br /> Have advance three breeding lines with unique sources of reistance to root-knot nematodes to the BC2F2 generation<br /> <br /> Objective 3: Facilitate and improve identification of nematode species and races. <br /> (AR) With Marco Cordero, we are investigating the morphological and molecular taxonomy of the Criconemoidea, a widespread and often damaging nematode group of over a dozen genera. Included will be photographic records of all species studied and descriptions of several new species we have identified as there are several species we are in the process of describing that are new to science. The first of 5 chapters has been submitted for publication and 2 more chapters are almost ready for submission. During 2011 a species of Cyst nematode, Heterodera urticae previously found only in Europe was found and reported.<br /> <br /> (MS) G. Lawrence/ Klink/K. Lawrence Molecular diagnostic tests have been developed and utilized to diagnose and to confirm Rotylenchulus sp. in Mississippi soils. DNA primers and probes were developed for a TaqMan probe quantitative PCR (qPCR)-based assay. The qPCR procedure could accurately detect the presence of Rotylenchulus sp. with a strong correlation (R² = 0.9924) between the morphologically (visually) observed number of number of soil extracted R. reniformis and the qPCR estimated number of nematodes from metagenomic DNA isolated from the same soil sample.<br /> <br /> (SC) Research includes studying the distribution and population density of Hoplolaimus species in soybean and cotton fields in South Carolina. Our objective is also to identify ecological and management factors potentially correlated to the presence of specific species of lance nematodes, and to develop molecular diagnostic methods to identify the main species of lance<br /> nematodes. <br /> <br /> (TX) Have adopted the PCR-based protocol of Adam et al. (2006) for the identification of M. marylandi.<br /> <br /> Impact Statements:<br /> (Arkansas) 1. Soybean-cotton rotations will continue to be the most economical means of nematode control until resistance is found in cotton.<br /> 2. Rotations have an environmental advantage over chemical nematicides by having no long lasting effect on the field or crop and is environmentally safe to use.<br /> <br /> (Alabama) 1. We identified cotton varieties resistance to Meloidogyne incognita are available to our growers. Resistant varieties also a less susceptible to Fusarium wilt.<br /> 2. Precision nematicide application can enhance cotton yield when the field is infested with Rotylenchulus reniformis. <br /> 3. Moisture stress potential is as important as initial nematode populations when selecting and applying nematicides.<br /> <br /> (Florida) 1. There is a lack of consistence in fruit yield of the resistant cultivars when grown in nonfumigated soil even though galling indicies were consistent very low.<br /> 2. The low percentage galling of resistant tomato cultivars vs. susceptible cultivars indicates that the root-knot nematode resistant Mi-1 gene in tomato was not broken by soil temperature under polyethylene films.<br /> <br /> (Georgia) 1. Root- systemic acquired resistance (SAR) against nematodes in cotton could be induced by applying a chemical analog of salicylic acid. SAR may contribute significantly to reducing the damage in cotton caused by nematodes. <br /> <br /> (Louisiana) 1. Research at LSU during this period was the first in the U.S. to document variation in reproduction and pathogenicity among geographic isolates of the reniform nematode, Rotylenchulus reniformis on soybean. 2. In 2010, research from the LSU AgCenter was also the first to document similar reproductive and pathogenic variation in reniform populations on cotton. <br /> <br /> (Mississippi) Lawrence 1. The host response of the crops used in our studies for resistance or susceptibility to plant-parasitic nematodes demonstrates the importance of continual variety examinations. There is a lack of resistance to the root-knot nematodes in corn hybrids currently available. With soybean there are indications that the introduction or shift of a SCN race will upset the resistance available to this specific race. We recovered a population of SCN identified as SCN race 15. In earlier studies after screening over 300 varieties found none to be resistant to this population. In examining recently developed varieties, resistance appears to be lacking.<br /> 2. Rotations with non-host crops will continue to be a major role in nematode management even with resistant varieties.<br /> 3. Nematode Detection Service - a web based service for nematode detection will allow the end-user to upload from ground data and see their results graphically.<br /> 4. A molecular diagnostic technique for the reniform nematode will increase the accuracy of detecting the presence and quantification of this pest in the soil.<br /> <br /> (South Carolina) 1. Soil samples are processed from South Carolina planted with soybean, cotton, and turf. We have identified Hoplolaimus galeatus and H. stephanus associated with turf and H. columbus associated with soybean and cotton. We have validated molecular methods for their identification.<br /> 2. In South Carolina, the Columbia Lance Nematode is found in 21% of soybean samples (124/600) and 59% of cotton samples (237/400), with densities ranging from 10 to 330 nematodes per 100 cc of soil. <br /> 3. In North Carolina, lance nematodes are found in only 10% of soybean fields, specifically in samples from Robeson, Scotland, Bertie, Camden, Pasquotank, Tyrell, Washington and Beaufort counties. The densities ranged from 10 to 70 nematodes per 100 cc of soil. Interestingly, none of these were identified as Columbia Lance Nematode. All of the species found were H.galeatus-like. <br /> 4. Additional samples from other southeastern states are included and have found Hoplolaimus magnistylus in Arkansas and Tennessee. <br /> <br /> (Texas) 1. Collaborated with USDA researchers in the development of BARBREN-713, an upland cotton genotype with resistance to root-knot and reniform nematodes will be officially released in 2012. <br /> 2. Advance three breeding lines with unique sources of resistance to root-knot nematodes to the BC2F2 generation<br />

Publications

Lawrence, K. S. and G. W. Lawrence. 2011. Chapter 14: Pest Management: Nematodes.In Conservation Tillage Systems: Production, Profitability and Stewardship. eds Bergtold, J. , Raper, R. , Hawkins, G., and Iversen, K. CRC Press LLC. (in review). <br /> <br /> Journal Articles:<br /> Moore, S. R., K. S. Lawrence, F. J. Arriaga, E. van Santen, C. H. Burmester. 2011. Influence of water infiltration and root growth on the downward dispersion of Rotylenchulus reniformis. Nematropica 42:1 73-79.<br /> <br /> Sikkens, R. B., D. B. Weaver, K. S. Lawrence, S. R. Moore, and E. van Santen. 2011. LONREN upland cotton germplasm response to Rotylenchulus reniformis inoculation level. Nematropica 41:66-72.<br /> <br /> Castillo, J. D., and Lawrence, K. S. 2011. First report of Catenaria auxiliaris parasitizing the reniform nematode Rotylenchulus reniformis on cotton in Alabama. Plant Disease 95(4):490 (http://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-07-10-0524?journalCode=pdis).<br /> <br /> Peer reviewed:<br /> Moore, S. R., K. S. Lawrence, S. Nightengale. 2011. Evaluation of cotton seed treatments for the control of root-knot nematode and Fusarium wilt on cotton, 2010.Report No. 5:N011 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Moore, S. R., K. S. Lawrence, B. E. Norris. 2011. Evaluation of experimental nematicides for the control of reniform nematodes on cotton in north Alabama, 2010. Report No. 5:N010 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Moore, S. R., K. S. Lawrence, J. R. Akridge. 2011. Evaluation of experimental nematicides for the control of reniform nematodes on cotton in south Alabama, 2010. Report No. 5:N009 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Moore, S. R., K. S. Lawrence, B. E. Norris. 2011. Evaluation of experimental nematicides for the control of reniform nematode on soybean in north Alabama, 2010.Report No. 5:N008 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Moore, S. R., K. S. Lawrence, B. E. Norris. 2011. Evaluation of seed treatment fungicides for the control of seedling disease on cotton in north Alabama, 2010. Report No. 5:ST020 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence, K. S., S. R. Moore, W. S. Gazaway, G. W. Lawrence, J. R. Akridge. 2011. Evaluation of cotton varieties with TeloneII for reniform management in cotton in south Alabama, 2010.Report No. 5:N006 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence, K. S., S. R. Moore, G. W. Lawrence, C. H. Burmester, C. Norris. 2011. Evaluation of seed treatments and seed quality in cotton seedling disease management in Alabama, 2010. Report No. 5:ST022 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence, K. S., S. R. Moore, G. W. Lawrence, C. H. Burmester, C. Norris. 2011. Evaluation of experimental seed treatments in cotton seedling disease management in Alabama, 2010.Report No. 5:ST021 DOI: 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Abstracts:<br /> Lawrence, K. S., G. W. Lawrence, V. Klink, and S. Moore. 2011. Host status of soybean differential genotypes to Rotylenchulus reniformis and Meloidogyne incognita race 3. Phytopathology 101:S99.<br /> <br /> Moore, S. R., K. S. Lawrence, B. Ortiz, J. Shaw, J. Fulton. 2011. Evaluation of the effects of soil moisture on the damage potential of Rotylenchulus reniformis on cotton. Phytopathology 101:S123<br /> <br /> Schrimsher, D. W., K. S. Lawrence, J. Castillo, S. R. Moore, J. W. Kloepper. 2011. Effects of Bacillus firmus GB-126 on the soybean cyst nematode mobility in vitro. Phytopathology 101:S161. <br /> <br /> Castillo, J. D., Lawrence, K. S.,and J. W. Kloepper. 2011. Evaluation of Bacillus firmus seed treatment for the biocontrol of reniform nematode Rotylenchulus reniformis on cotton plants. Phytopathology 101:S29. <br /> <br /> Proceedings: <br /> Moore, S. R., K. S. Lawrence. 2011. Effects of soil type on the reproductive potential of Rotylenchulus reniformis on cotton. Proceedings of the Beltwide Cotton Conference, Vol. 1, 235 - 240.National Cotton Council of America, Memphis, TN.www.cotton.org/beltwide/proceedings.<br /> <br /> Sikkens, R. B., S. R. Moore, K. S. Lawrence, T. Wu, D. B. Weaver. 2011. LONREN germplasm response to nematode inoculation level. Proceedings of the Beltwide Cotton Conference, Vol. 1, 728 - 736.National Cotton Council of America, Memphis, TN.www.cotton.org/beltwide/proceedings.<br /> <br /> Weaver, D. B., R. B. Sikkens, S. R. Moore, K. S. Lawrence, R. Sharpe. 2011. LONREN x FM966 progeny evaluation in a field infested with reniform nematode. Proceedings of the Beltwide Cotton Conference, Vol. 1, 737 - 741.National Cotton Council of America, Memphis, TN.www.cotton.org/beltwide/proceedings.<br /> <br /> Scott, Tamara Z., K.S. Lawrence, K. Glass, J.D. Castillo. 2011. Fusarium wilt Identification and Root-Knot Nematode Effects on Commercial Cotton Cultivars in 2010. Proceedings of the Beltwide Cotton Conference, Vol. 1, 224  229. National Cotton Council of America, Atlanta, GA. www.cotton.org/beltwide/proceedings.<br /> <br /> Castillo, J.D., Lawrence, K.S.,and J.W. Kloepper. 2011. Evaluation of Bacillus firmus (Votivo®) Paecilomyces lilacinus strain 251 for the biocontrol of reniform nematode Rotylenchulus reniformis. Proceedings of the Beltwide Cotton Conference, Vol. 1, 242 - 246.National Cotton Council of America, Memphis, TN.www.cotton.org/beltwide/proceedings.<br /> <br /> Ballard, B. B. K. S. Lawrence, E. J. Sikora, and J. F. Murphy. Initial response of soybean mosaic virus, bean pod mottle virus and Rotylenchulus reniformis on soybean. Proceedings of the Beltwide Cotton Conference, Vol. 1, 219 - 223. National Cotton Council of America, Memphis, TN.www.cotton.org/beltwide/proceedings.<br /> <br /> Lawrence, G.W. K.S. Lawrence and B. Haygood. 2011. Efficacy of Dow AgroSciences seed treatment fungicide STP 20143 for the management of the seedling disease complex of cotton. Proceedings of the National Beltwide Cotton Conference, Vol. 1, National cotton Council, Memphis TN. Online: www.cotton.org/beltwide/proceedings. <br /> <br /> Bennett, R.S., A.L. Bell, J.E. Woodward, K.S. Lawrence, C.S. Rothrock, T.L. Kirkpatrick, G.W. Lawrence, P.D. Colyer, and R.M. Davis. 2011. Report progress on a contemporary survey of the Fusarium wilt fungus in the United States. Proceedings of the National Beltwide Cotton Conference, Vol. 1, National cotton Council, Memphis TN. Online: www.cotton.org/beltwide/proceedings.<br /> <br /> <br /> (Arkansas)<br /> Journal Articles:<br /> Chen, P., T. Ishibashi, C. H. Sneller, J. C. Rupe, D. G. Dombek, R. T. Robbins, and R. D. Riggs. 2011. Registration of UA 4910 Soybean. Journal of Plant Registrations, Vol. 5, No. 1, January 2011. <br /> <br /> Chen, P., T. Ishibashi, C. H. Sneller, J. C. Rupe, D. G. Dombek, and R. T. Robbins. 2011. Registration of R991613F, R012731F, and R013474F Soybean Germplasm Lines with Diverse Pedigrees. Journal of Plant Registrations, Vol. 5, No. 2, May 2011.<br /> <br /> Robbins, R. T., E. Shipe, P. Arelli, P. Chen, G. Shannon, K. M. Rainey, L. E. Jackson, E. E. Gbur, D. G. Dombek, & J. T. Velie. 2011. Reniform nematode reproduction on soybean cultivars and breeding lines in 2010. Proceeding of the 2011 Beltwide Cotton Conferences, Atlanta, Georgia, January 4-7, 2011, Pgs. 167-174.<br /> <br /> <br /> Abstracts:<br /> J.G. Shannon, J. A. Wrather, M.A. Woolard, S.L. Smothers, S.M. Pathan, H.T. Nguyen, and R.T. Robbins. 2011. 805-11482- a high yielding soybean with resistance to multiple diseases and nematode species. Proceeding of the Southern Soybean Disease Workers. Fort Walton Beach FL.<br /> <br /> Robbins, R. T., and L. E. Jackson. 2011. Soybean Varieties and Breeding Lines Shown With Resistance to Reniform Nematode in Greenhouse Tests, 1998-2010. Proceeding of the Southern Soybean Disease Workers. Fort Walton Beach FL.<br /> <br /> Robbins, R. T., E. Shipe, P. Arelli, P. Chen, G. Shannon, K. M. Rainey, L. E. Jackson, E. E. Gbur, D. G. Dombek, and J. T. Velie. 2011. Reniform Nematode Reproduction on Soybean Cultivars and Breeding Lines in 2010. Proceedings of the Beltwide Cotton Conferences, Atlanta.<br /> <br /> Robbins, Robert T., and W. Ye. 2011. Heterodera urticae, Cooper 1955, a Heterodera goettingiana-group cyst nematode found in Arkansas. <br /> <br /> Cordero, M., R. T. Robbins, and A. L. Szalanski. 2011. Phylogenetic relathionships among nematodes of the suborder criconematina using ITS-1 rdna region. <br /> <br /> (Georgia)<br /> Aryal, S. K., R. F. Davis, K. L. Stevenson, P. Timper, and P. Ji. 2011. Induction of systemic acquired resistance by Rotylenchulus reniformis and Meloidogyne incognita in cotton following separate and concomitant inoculations. Journal of Nematology: 43: (in press)<br /> <br /> Aryal, S. K., R. F. Davis, K. L. Stevenson, P. Timper, and P. Ji. 2011. Influence of infection of cotton by Rotylenchulus reniformis and Meloidogyne incognita on the production of enzymes involved in systemic acquired resistance. Journal of Nematology: 43: (in press)<br /> <br /> (Louisiana) <br /> McGawley, E.C.; C. Overstreet, and M.J. Pontif. 2011. Variation in reproduction and pathogenicity of geographic isolates of Rotylenchulus reniformis on soybean. Nematropica: 41: 12-22. <br /> <br /> (Minnesota)<br /> Zheng, J. W., and S. Y. Chen. 2011. Estimation of virulence type and level of soybean cyst nematode field populations in response to resistant cultivars. Journal of Entomology and Nematology 3:37-43. <br /> <br /> Lian, L., F. Wang, R. Denny, P. Schaus, N. Young, J. Orf, and S. Chen. 2011. Identifying novel sources of resistance to the soybean cyst nematod. Abstracts of 1st Annual National Association of Plant Breeders Meeting. Http://www.plantbreeding.org/napb/Meetings/2011/Abstracts11e05dsSJ.pd: 28.<br /> <br /> (Mississippi) <br /> Fang, D. D. and Stetina, S. R. 2011. Improving cotton (Gossypium hirsutum L.) plant resistance to reniform nematodes by pyramiding Ren1 and Ren2. Plant Breeding 130:673-678.<br /> <br /> Arias, R. S., Stetina, S. R., and Scheffler, B. E. 2011. Comparison of whole-genome amplications for microsatellite genotyping of Rotylenchulus reniformis. Electronic Journal of Biotechnology. DOI: 10.2225/vol14-issue3-fulltext-13.<br /> <br /> (Mississippi) Lawrence<br /> Book Chapters:<br /> <br /> Journal Articles:<br /> Doshi, R. A., King, R. L., and Lawrence, G. W. 2011. Classification of Rotylenchulus reniformis numbers in cotton using remotely sensed hyperspectral data on self-organized maps. Journal of Nematology 42 179-193. <br /> <br /> Kurt Showmaker, Gary W. Lawrence, Shien Lu, Clarissa Balbaian and Vincent P. Klink. 2011. Quantitative field testing Rotylenchulus reniformis DNA from metagenomic samples isolated directly from soil. PLoS ONE 6(12) e28954. Doi:10.1371/journal.pone.0028954. <br /> <br /> Proceedings:<br /> <br /> Lawrence, G.W. K.S. Lawrence and B Haygood. 2011. Efficacy of Dow AgroSciences seed treatment fungicide STP 20143 for the management of the seedling disease complex of cotton. Proceedings of the National Beltwide Cotton Conference, Vol. 1, National cotton Council, Memphis TN. Online: www.cotton.org/beltwide/proceedings. <br /> <br /> Lawrence, K.S., G.W. Lawrence and S.R. Moore. 2011. New nematicide potentials in cotton in the southeast and mid south. Proceedings of the National Beltwide Cotton Conference, Vol. 1, National cotton Council, Memphis TN. Online: www.cotton.org/beltwide/proceedings. <br /> <br /> Bennett, R.S., A.L. Bell, J.E. Woodward, K.S. Lawrence, C.S. Rothrock, T.L. Kirkpatrick, G.W. Lawrence, P.D. Colyer, and R.M. Davis. 2011. Report progress on a contemporary survey of the Fusarium wilt fungus in the United States. Proceedings of the National Beltwide Cotton Conference, Vol. 1, National cotton Council, Memphis TN. Online: www.cotton.org/beltwide/proceedings. <br /> <br /> Abstracts & Others:<br /> Lawrence, K. S., G. W. Lawrence, V. Klink, and S. Moore. 2011. Host<br /> status of soybean differential genotypes to Rotylenchulus reniformis and<br /> Meloidogyne incognita race 3. Phytopathology 101:S99.<br /> <br /> Lawrence, K. S., S. R. Moore, W. S. Gazaway, G. W. Lawrence, J. R.<br /> Akridge. 2011. Evaluation of cotton varieties with TeloneII for reniform<br /> management in cotton in south Alabama, 2010.Report No. 5:N006 DOI:<br /> 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence, K. S., S. R. Moore, G. W. Lawrence, C. H. Burmester, C.<br /> Norris. 2011. Evaluation of seed treatments and seed quality in cotton<br /> seedling disease management in Alabama, 2010. Report No. 5:ST022 DOI:<br /> 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence, K. S., S. R. Moore, G. W. Lawrence, C. H. Burmester, C.<br /> Norris. 2011. Evaluation of experimental seed treatments in cotton<br /> seedling disease management in Alabama, 2010.Report No. 5:ST021 DOI:<br /> 10.1094/PDMR05. The American Phytopathological Society, St. Paul, MN<br /> <br /> (South Carolina)<br /> Leach, M.M., P. Agudelo, A.L. Lawton-Rauh. 2011. Genetic Variability of Rotylenchulus reniformis. Plant Disease 96:24-29. <br /> <br /> Ma, X., P. Agudelo, J.D. Mueller, and H.T. Knap. 2011. Molecular Characterization and Phylogenetic Analysis of Hoplolaimus stephanus. Journal of Nematology 43:25-34.<br /> <br /> Leach, M.M., P. Agudelo, A.L. Lawton-Rauh. 2011. Effect of Crop Rotations on Population Structure of Reniform Nematode, Rotylenchulus reniformis. Plant Disease 96:30-36. <br /> <br /> Agudelo, P., S.A. Lewis, B.A. Fortnum. 2011. Validation of a Real-time PCR Assay for the Identification of Meloidogyne arenaria. Plant Disease 95: 835-838.<br />

Impact Statements

1. - Cotton germplasm BARBREN-713 was identified as the best genotype to work with to develop reniform nematode resistant cotton lines.
2. - A good rotation, such as corn-cotton, sorghum-cotton or reniform resistant soybean-cotton can restore profitability to fields infested with soybean cyst nematode.
3. - Nematode Detection Service - a web based service for nematode detection allows the end-user to upload from ground data and see their results graphically.
4. - A molecular diagnostic technique for the reniform and soybean cyst nematodes increases the accuracy of detecting the presence and quantification of these pests in the soil.
5. - The release of N7003CN facilitates the use of varieties resistant to root-knot and reniform nematodes. It is the first maturity group VII variety with resistance to race 2 of soybean cyst nematode.
6. - Sorghum hybrids with good field tolerance to root-knot and lance nematoides have been identified
7. - Release of peanut cv Webb, a cultivar with resistance to root-knot nematode, sclerotinia blight, tomato spotted wilt virus and has the high oleic to linoleic fatty acid trait.
8. - Release of BARBREN, a cotton breeding line with resistance to reniform nematode derived from Gossypium barbadense GB713 and resistance to root-knot nematode derived from G. hirsutum M315.
9. - The use of Meloidogyne incognita resistant tobacco over the last 30-40 years has resulted in a dramatic shift of root-knot species to M. arenaria, M. hapla, and M. javanica and various mixtures of two or more of these four species making the resistance to M. incognita less useful for reducing the economic impact of these root-knot nematodes.
10. - A new technique for viewing the perineal pattern of root-knot nematodes greatly improves their value for routine species identifications.
11. - Quantification of the effect of soil texture and irrigation on yield losses caused by reniform nematode on cotton.

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Report Information

Participants

Agudelo, Paula (pagudel@clemson.edu) - (SC)
Dickson, Don (dwd@ufl.edu)- (FL)
Eisenback, Jon (jon@vt.edu) -(VA)
Faske, Travis (tfaske@uaex.edu) - (AR)
Hewezi, Tarek (thewezi@utk.edu) - (TN)
Johnson, Charles (spcdis@vt.edu) - (VA)
Lawrence, Gary (glawrence@entomology.msstate.edu) - (MS)
Lawrence, Kathy lawrekk@auburn.edu) - (AL)
Thies, Judy (jthies@ars.usda.gov) - (SC)
Lacewell, Ron (r-lacewell@tamu.edu) - (TX).

Brief Summary of Minutes

The meeting was convened at 1:00 p.m. at the Hyatt Regency in Greenville, S.C.
Scientists in attendance (and the state they represent) were: Paula Agudelo (SC), Don Dickson (FL), Jon Eisenback (VA), Travis Faske (AR), Tarek Hewezi (TN), Charles Johnson (VA), Gary Lawrence (MS), Kathy Lawrence (AL), Judy Thies (SC), and Ron Lacewell (Administrative Advisor for S-1046, TX).
Ron Lacewell commented on this being a meeting that is the last one before a new program is started. The new project needs to be written by next year.
The committee synthesized the objectives of the new project and assigned working groups to write the new proposal as follows.
Objective 1 Integrate biological and cultural management tactics with the use of resistant cultivars to develop sustainable crop production systems. (Travis Faske and Judy Thies)
Objective 2 Elucidate molecular and physiological mechanisms of plant-nematodes interactions to improve host resistance. (Tarek Hewezi and Vince Klink)
Objective 3 Advance the tools for identification of nematode species and characterization of intraspecific variability. (Paula Agudelo and Jon Eisenback)
Title: Development of more sustainable crop production practices for management of plant-pathogenic nematodes.
Justification, Methods, Literature Review: (Written by Objective chairs)
Chair of writing committee: (Chuck Johnson)
Date timeline: Sept. 1, 2014
Oral reports for S-1046 were presented as follows: Graduate students from Auburn University, Clemson University, Mississippi State University and Virginia Tech gave progress reports on their research (10 presentations).

November 8, 2012: State reports:
Oral reports by graduate students were completed (1presentation)
Members of S-1046 report was presented: Judy Thies (USDA-SC alternative control of root-knot nematode), Kathy Lawrence (AL- RKN and reniform on cotton), Travis Faske (AR - root-knot on soybean), Don Dickson (FL- root-knot nematodes on tomato and peanut), Gary Lawrence (MS-reniform and root-knot) Paula Agudelo (SC - root-knot), Jon Eisenback (VA- root-knot nematodes), Paula Agudelo (SC  root-knot nematodes grain sorgum, lance, lesion, and root-knot, soybean), Tarek Hewezi (TN - root-knot resistance cotton), Charles Johnson (VA - root-knot tobacco), Jon Eisenback (VA - reniform cotton)
Business meeting:
Called to order at 11:40 a.m. Kathy Lawrence moved to approve minutes from previous meeting. Travis Faske seconded and all agreed. Minutes were approved as distributed by e-mail.
Potential new members were discussed. A new member from Texas is needed, North Carolina needs to be more active (Rick Davis)
The next meeting will be in Williamsburg, Virginia in late October or early November of 2014. The dates will be decided soon. Jon Eisenback (new president) will communicate with members for planning. Graduate student presentations will be encouraged at this meeting.
Kathy Lawrence (new secretary) will plan the meeting in 2015 in Alabama.
Chuck Johnson will be the new project chair in charge of writing. He will establish a timeline for the development of the new project. Nov. 2014 was set as the deadline.
All sections are reminded to compare our project with the Western Regional Multistate Project.
Joint meeting with other groups was discussed.
The idea of getting approval for more than five years was discussed.
Graduate student participation was encouraged at the next multistate meeting.
Meeting adjourned at 12:00 noon.

Accomplishments

Objective 1: Integrate resistant cultivars with other nematode management tactics to reduce selection pressure on nematode populations and communities. <br /> (Alabama) Multiple methods, stains, and irritants have been used to determine if plant-parasitic nematodes are alive or dead once exposed to a pesticide or biological compounds. The objective of this research project was to select an optimal technique to rapidly distinguish live and dead second stage juveniles (J2s) of soybean cyst nematode (SCN, Heterodera glycines). In vitro assays were used to select the best irritant of 1N sodium carbonate (Na2CO3), 1N sodium bicarbonate (NaHCO3), or 1N sodium hydroxide (NaOH). Further test evaluated the optimum pH, the application contention, and time of movement. Tests were established in 100µl 96-well plates or in 50 ml conical tubes. Each trial was repeated twice and each treatment had four replications. A growth chamber experiment to confirm the results of the in vitro screening was also conducted. Results indicated statistically, 1µl 1N Na2CO3, 10 µl 1N NaHCO3, and 20µl 1N NaOH at pH=10 were equally (P < 0.05) effective at determining live SCN J2s. The 10 µl 1N NaHCO3 and 20µl 1N NaOH solutions increased movement of the nematodes with the normal lateral undulations. The 1µl 1N Na2CO3 at pH=10 caused SCN J2s to display a rapid twisting movement after a 1 minute exposure which was easy to visually see. Death also occurred after 30 minutes exposure in 20µl 1N Na2CO3, although 20µl 1N NaHCO3 did not terminate the nematodes. Furthermore, live J2s were confirmed alive and infective in a growth chamber test. The 1µl 1N Na2CO3 in100 µl of nematode solution at pH=10 determined that 80% of the SCN J2s were alive and of those, 46.3% entered soybean roots when they were placed near the root zone. The results confirmed that the optimum sodium agitation technique for rapidly distinguishing live and dead SCN J2s, accurately indicated live viable J2s. <br /> <br /> Fusarium wilt (Fusarium oxysporum f. sp. vasinfectum, FOV) is a serious disease of cotton, and is intensified by the presence of root-knot nematodes (Meloidogyne incognita). Twenty total cultivars were tested for Fusarium wilt resistance in addition to susceptible (Rowden) and resistant (M-315) checks in a randomized complete block design located at E. V. Smith Research Center, Plant Breeding Unit, near Tallassee, Alabama. The Fusarium wilt disease pressure was excellent in 2012. FOV races 1 and 3 were the races of the fungus isolated most frequently in 2012. The varieties showing the highest resistance with the lowest levels of disease incidence were DP0912B2RF, PHYPX443314WRF, PHY367WRF, DG2570B2RF, FM1346GLB2 and FM1348GLB2. The cultivars with lowest populations of root knot eggs per gram of root were PHY367WRF, PHYPX443314WRF, and DP1252B2RF. Cultivars with yields statistically similar to and higher than the M-315 resistant check were DG2570B2RF, FM1346GLB2, and FM1348GLB2, producing 3369, 3640, and 3343 lbs/a of seed cotton, respectively. Although these cultivars had comparable high yields, each supported a higher density of root-knot eggs than the resistant M-315 check. Thus these varieties may have some tolerance to rootknot nematode but not resistance. <br /> <br /> (Arkansas) R. T. Robbins: In a field with a high population of race 5 SCN on the Marianna Experiment station a planted for a second year in a 3 year soybean rotation cycle in which susceptible, moderately resistant and very resistant varieties were planted. Yield of the susceptible was 28.9 Lbs in the 2 middle rows of the 90 ft rows, the moderately resistant 32.9 Lbs, and the highly resistant 35.9 Lbs. The susceptible averaged 4,607 eggs per 100 ML soil, the moderately resistant averaged 3,380 eggs and the very resistant averaged 1,223 eggs.<br /> <br /> I tested 142 soybean entries new to the Arkansas Soybean Variety Testing program soybean The following 8 entries: MPG-S-5214NRR, ARMOR X1410, Willcross RY2513N, Leland, ARMOR X47C, Schillinger 4712R2, and Eagle Seed 5650RR from the 142 new varieties were not different than the resistant checks Forrest, Anand and Hartwig. These 8 entries may be useful in a cotton-soybean rotation to reduce numbers <br /> <br /> Also tested were 125 lines from Southern Soybean Breeders (2 from USDA Jackson TN, 41 from Arkansas; 20 from Missouri; and 62 from Southern Illinois - Carbondale) for resistance to the reniform nematode (Rotylenchulus reniformis).<br /> <br /> T. R. Faske: Cotton acreage has decreased in Arkansas and many of those acres have been replaced by corn or soybean. In the northeast corner of the state, peanut production has given producers a profitable crop in rotation with corn and soybean, especially were root-knot was a issue. <br /> <br /> (Minnesota) Impact of cultivar resistance on virulence phenotypes of the soybean cyst nematode: A field plot experiment was established in Lamberton, Minnesota in 2008 to determine the effect of different sequences of SCN-resistance sources (PI 887888, Peking, and PI 437654) on dynamics of SCN population densities and their virulence phenotypes (HG Types or races). The site was initially infested by SCN race 1 (HG Type 2.5.7) that can overcome PI 88788 resistance, the source of resistance of majority commercial resistant cultivars. After three years, only the monoculture of Pioneer 91M90 carrying Peking resistance significantly increased FI on the source of resistance Peking, resulting in change of the SCN population from HG Type 2 to HG Type 1,2 which can overcome the resistance in both Peking and PI 88788.<br /> <br /> (MISSISSIPPI) Emergence of new nematicidal products. Several agricultural chemical companies are in the process of developing products designed for nematode control in row and vegetable crops (Table 1).<br /> <br /> <br /> Table 1. Experimental and Existing Nematicidal Product by Company, Product and <br /> Application Method.<br /> <br /> Company Product Application<br /> <br /> AMVAC Counter 20G In-furrow granular<br /> Bayer L1946 Seed treatment<br /> L1947 Seed treatment<br /> L1999 Seed treatment<br /> BCS-AR83685 Seed treatment<br /> Velum Total In-furrow spray<br /> Aeris seed applied system Seed treatment<br /> Votivo Seed treatment <br /> DuPont Vydate L In-furrow spray<br /> Vydate C-LV Foliar spray<br /> Q8U80 In-furrow spray<br /> Helena HM 0736 In-furrow spray<br /> HM 1303 In-furrow spray<br /> HM 1302 Seed treatment <br /> MANA MCW-2 In-furrow spray<br /> Monsanto Numbers Seed treatment<br /> Marrone MBI 203 Seed treatment<br /> MBI 206 Seed treatment<br /> MBI 302 Seed treatment<br /> Syngenta Avicta Complete Seed treatment<br /> STP 21403 Seed treatment<br /> STP 22411 <br /> <br /> Evaluation of seed treatment and foliar nematicides on the growth and development of upland cotton in soils infested by the reniform nematode. Randy Smith, Ph.D student, Project Directors: Kathy and Gary Lawrence. <br /> <br /> Evaluate the growth and development of upland cotton fruiting patterns relative to the impacts of 1.) heavy nematode infestations and nematicide combinations on long and short season varieties, 2.) nematicidal applied seed treatments and 3.) Potassium (potash) in soils infested with the reniform nematode. <br /> <br /> Effects on plant development are followed by plant mapping. Cotton plants grow and mature in orderly phases. Growth responses to stress produced by nematodes will alter specific phases of plant development. The period of plant development that it occurs can be determined by plant mapping.<br /> <br /> <br /> (North Carolina) Soybean lines and cultivars with potential resistance derived from PI437564 were evaluated for yield and resistance to soybean cyst nematode in a field trial in Chowan County, NC. The same soybean lines were evaluated in Johnston County, NC against Meloidogyne enterolobii (guava root-knot nematode), a species of root knot nematode newly found in North Carolina. <br /> <br /> (South Carolina) The acreage of grain sorghum grown in the Southeastern United States has increased dramatically in the last several years due to increased demand for grain from the swine industry. There are contradicting reports on the host status of Sorghum bicolor to Meloidogyne incognita, no data is available on the host status to Hoplolaimus columbus, and there is very little information on its reaction to lesion nematodes. Host suitability of 10 grain sorghum hybrids, to M. incognita (SRK), H. columbus (CLN) and Pratylenchus spp. (lesion) were evaluated under field conditions at the Edisto REC near Blackville, SC. Ten hybrids were arranged in three strip-blocks with hybrid as the whole plot and treatment with 28 L ha-1 of 1, 3-dichloropropene (1, 3-D) as the strip plot. Each plot consisted of 4 rows 10-m long on 96-cm centers. Two sets of plots were established. The first was in a field infested primarily with SRK and CLN and the second in a field infested primarily with CLN. Both fields were infested with lesion nematodes. Nematode samples were collected from soil at planting, 6-weeks-after planting and near harvest. Roots were collected just prior to harvest for extraction of nematodes in a mist chamber. In the first field, 1, 3-D treatment increased mean yields from 2,887 to 3,703 kg ha-1 over the 10 hybrids. Yields did not differ among the hybrids. Treatment with 1, 3-D reduced recovery of CLN at harvest from 54.3 g-1 to 10.6 g-1 of dry root. The hybrids did not vary in the number of CLN on root at harvest. Recovery of lesion from roots, and CLN, lesion and SRK from soils at harvest were not affected by 1, 3-D treatment or hybrid. The reduction in CLN caused by the 1, 3-D treatment appears to have resulted in a 28% yield increase. In the second field 1, 3-D treatment did not affect mean yield of the grain sorghum hybrids. However, the hybrids yield did vary from 3,055 kg ha-1 to 6,032 kg ha-1. Yield of NK7633 was significantly less than Pioneer 83P17, Pioneer 83G66, DKS 44-20, DKS 53-67 and NK 7829. Recovery of CLN from roots appeared to be higher for untreated than 1, 3-D treated plants at harvest (110.0 g-1 and 35.0 g-1 of dry roots, respectively). Recovery of CLN from roots did not vary among hybrids. Recovery of lesion nematodes from roots, and CLN, lesion and SRK from soil at harvest were not affected by either 1, 3-D treatment or hybrid. Based on this study, grain sorghum may prove useful in managing SRK populations, but may be susceptible to yield losses due to CLN.<br /> <br /> <br /> Objective 2: Identify and incorporate new sources of resistance into elite germplasm lines and cultivars. <br /> <br /> (Alabama) Germplasm lines LONREN-1 and LONREN-2 were released in 2007 for cotton breeders to incorporate R. reniformis nematode resistance into breeding efforts with desirable cultivars to establish nematode resistant high yielding cultivars. Previous screenings for R. reniformis resistance in the LONREN-1 × FM966 breeding lines developed at Auburn University have demonstrated that the nematode resistance is accompanied by severe stunting and limited plant growth followed by low yields. The objectives of this study were to evaluate the effects that applying nematicides to selected LONREN breeding lines have on R. reniformis nematode populations, early seedling plant stunting, yield, and fiber quality. Three resistant breeding lines from the LONREN-1 × FM966 cross, one susceptible line from the LONREN-1 × FM966 cross, as well as LONREN-1 and the susceptible cultivar DP393 were treated with nematicides and their performances evaluated. In the greenhouse, nematicides increased plant heights in the resistant lines. Nematicides further reduced reniform populations in the resistant lines 45 days after planting (DAP). Rotylenchulus reniformis populations were 50% lower in the resistant lines compared to the susceptible lines by the end of the growing period. In microplot and field trials, the phenotypic stunting response of the resistant lines was reduced by nematicides with increases in plant heights at 30 and 75 DAP. Increases in yields were also evident in the resistant breeding lines that were treated with nematicides. The study also included BARBREN-713, a more recent experimental germplasm line, which incorporates resistance to R. reniformis from the wild accession GB713 of G. barbadense. At all three trial locations (greenhouse, microplots and field), BARBREN-713 outperformed the LONREN derived lines as well as DP393 in terms of seed cotton yields, while having significantly lower egg counts than the susceptible genotypes. <br /> <br /> (Arkansas) R. T. Robbins: I am collaborating with Drs. Grover Shannon (Soybean Breeder) and Tri D. Vuong (Soybean Biotechnologist) on developing reniform molecular markers for reniform nematode resistance in soybean. In 2012 we are testing 246 lines derived from the parent lines Magellan and PI 438489B and 242 lines derived from Magellan an PI437690. This is a project funded by the Missouri soybean producers for 2 years. I am also collaborating with Dr. P. Chen (Arkansas) on nematode resistance in his soybean lines. I am also conducting proprietary contract studies with Phytogen Seed Company looking for reniform resistance in cotton.<br /> <br /> T. R. Faske: Recently, I identified and characterized a unique source of resistance to M. incognita in a wild botanical variety of Cucumis melo. Cucumis melo var. texanus is commonly found in agricultural fields in the Southern U.S. and Mexico. Its resistance to M. incognita was similar in magnitude and mode of resistance to that of C. metuliferus, a highly resistant species. The fact that C. metuliferus is incompatible with C. melo has limited this resistance being incorporated into melon varieties. The F1 and F2 generation will be screened in the greenhouse to determine if this source of resistance can be incorporated into C. melo. This may be a useful source of resistance in cantaloupe and honeydew melon production.<br /> <br /> (Minnesota) Identify and incorporate new sources of resistance into elite cultivars. Breeding: Several soybean lines carrying SCN-resistance different from the sources PI 88788 and Peking were used for breeding SCN-resistant cultivars. Crosses were made in 2009, 2010, 2011, and 2013. The progenies of the crosses will be evaluated for SCN resistance.<br /> <br /> (Mississippi) Soybean Cyst: Functional analysis of Glycine max genes identified from its resistant reaction to its major parasitic nematode pathogen, Heterodera glycines. <br /> Shankar Pant, G.W. Lawrence, V.P. Klink<br /> <br /> Tests are in process to identify genes that are involved in the resistance of Glycine max (soybean) to the Heterodera glycines (soybean cyst nematode [SCN]). To identify these genes involves isolation of syncytia cells formed by SCN that are undergoing compatible or incompatible reactions at different times during the reactions. The RNA was isolated from these cells and used in comparative gene expression analyses. Candidate resistance genes were identified and then genetically engineered into soybean plants that are normally susceptible to SCN. The results from examining the function of 62 candidate genes demonstrate that some of the genes play a role in resistance. Further experimentation is ongoing to understand the details of the process of resistance.<br /> <br /> The use of RNAi in functional analyses of soybean genes involved in suppressing soybean cyst nematode (SCN) infection. Brant T. McNeece, G.W. Lawrence, V.P. Klink.<br /> The interaction between soybean and the soybean cyst nematode (SCN) results in a 7-10% decrease in production worldwide. The SCN is capable of inducing the formation of multinucleate feeding structure known as a syncytium that is the site of parasitism. Syncytia undergoing an incompatible reaction to SCN parasitism were analyzed for gene expression that is active specifically during the incompatible reaction. These genes were then expressed in a susceptible genotype (Williams 82). Two genes, MSU12-1 and MSU13-1, when expressed to high levels in the susceptible Williams 82 genotype resulted in suppressed SCN infection. To confirm that the gene was involved in suppressing SCN infection, MSU12-1 and MSU13-1 was engineered as RNAi constructs into Peking/PI 548402 which is a genotype that is normally resistant to SCN. RNAi is used to decrease the normal RNA levels of a target gene, acting as a hypomorphic condition. As hypothesized, SCN growth is increased significantly in these roots where MSU12-1 and MSU13-1 gene activity is suppressed. The combination of overexpression and RNAi in the high throughput gene testing pipeline is a useful tool in examining the function of large numbers of candidate genes. <br /> <br /> (Mississippi - USDA) Efforts to identify and incorporate useful levels of resistance to reniform nematode (Rotylenchulus reniformis) into upland cotton (Gossypium hirsutum) continued at the USDA ARS in Stoneville, MS. Several germplasm lines with moderate resistance from less-adapted day-neutral Texas race stock lines of G. hirsutum tested in advanced trials in 2011 and 2012 did not significantly reduce soil populations of reniform nematode when data from both years were evaluated, and further development of these materials was abandoned. In this project, we also are working to transfer high levels of reniform nematode resistance from five unique relatives of upland cotton (G. aridum, G. arboreum, G. longicalyx, G. barbadense, and G. herbaceum), and marker assisted selection is being used as appropriate to facilitate this effort. Phenotypic screening of progeny with resistance from G. aridum, G. arboreum, or both sources, combined with post-screening recovery of resistant plants was used to advance materials to the current BC4F6 generation. However, we continue to lose a significant number of lines with markers for resistance with each generation that the material advances. Plot tests of advanced generation materials developed from moderately resistant but previously untested day-neutral Texas race stock lines of G. hirsutum, one resistant G. hirsutum accession, and highly resistant accessions of G. barbadense were initiated this year, but data collection and analysis are not yet complete. Collaborative work with cotton breeders at Mississippi State University resulted in progeny with confirmed resistance from G. longicalyx (LONREN 1 and LONREN 2 sources of resistance) that show acceptable to excellent yield potential and fiber quality. Many of these were tested in 2012 and 2013 yield trials at multiple locations; data collection and analysis for 2013 is still in progress.<br /> <br /> Identification of reniform nematode resistance in soybean (Glycine max) and incorporation of resistance into soybean breeding efforts continued. Of 61 wild and domestic lines evaluated to date, six previously untested lines (two released germplasm lines, one accession, and 3 advanced breeding lines) were found to have useful levels of resistance. In addition to identifying new sources of reniform nematode resistance, we are making crosses to the resistance sources and have initiated phenotypic screening of our first F2 populations. Concurrent DNA collection will allow us to determine the inheritance of the resistance from each source and identify molecular markers (SSR and/or SNP) that can be used in marker assisted breeding.<br /> <br /> (North Carolina) Screening of elite lines of soybean germplasm for resistance to races 2 and 4 of soybean cyst nematode in the greenhouse continued. Soybean lines and cultivars with potential resistance derived from PI437564 were evaluated for yield and resistance to soybean cyst nematode in a field trial in Chowan County, NC. The same soybean lines were evaluated in Johnston County, NC against Meloidogyne enterlobii (guava root-knot nematode), a species of root knot nematode newly found in North Carolina. The root-knot nematode parasitism genes 8D05, 35F03, and 5G05 were found to play a significant role in nematode infection of plant roots. The secreted 8D05 RKN protein interacted with a plant tonoplast intrinsic protein (aquaporin) and appears to play a role in water and solute transport in nematode feeding cells. Transgenic plant-derived RNAi (RNA interference) against the 8D05, 35F03, and 5G05 genes resulted in significant, strong reduction in plant root infection by root-knot nematodes. <br /> <br /> (South Carolina - USDA) Melons including cantaloupe and speciality melons such as honeydew and Galia melons are extremely susceptible to the southern root-knot nematode (Meloidogyne incognita). Significant yield losses occur when these susceptible melons are grown in root-knot nematode (RKN) fields. Until its ban, methyl bromide was used for decades as a pre-plant soil fumigant for controlling RKN. Now, there is an urgent need to develop alternative methods for managing this important pest in melons and other vegetable crops. In Asia, the Mediterranean, and Europe, grafting susceptible melon scions on disease resistant rootstocks is being used for managing soil-borne diseases. Unfortunately, the bottle gourd and hybrid squash rootstocks which are commonly used for grafted melons are highly susceptible to RKN. In previous studies, African horned cucumber has been reported to be resistant to RKN and may be useful as rootstocks for grafted melon. In order to identify African horned cucumber (Cucumis metulifer) accessions which are highly resistant to RKN, we conducted greenhouse studies to evaluate the response to M. incognita of all 39 Plant Introductions (PI) of African horned cucumber available in the USDA African horned cucumber PI Collection. Several PI were moderately to highly resistant to M. incognita in the greenhouse tests and these PI were evaluated in a field which was highly infested with root-knot nematodes in Charleston, SC. A number of the African horned cucumber PI exhibited moderate to high resistance to root-knot nematodes in the field test. The most resistant African horned cucumber accessions can be used for developing highly resistant rootstocks for grafted melon and may be used for managing RKN in melon in the Southern U.S. <br /> <br /> (Tennessee) Specific aims: 1- Identifying major soybean resistance/susceptibility genes that are epigenetically controlled during SCN parasitism of soybean. 2- Describing the functional roles of phytohormones and protein kinases in mediating plant susceptibility/ resistance to cyst nematodes. <br /> <br /> Summary for Specific aim#1: All genes that mediate epigenetic modifications in the nematode feeding site (syncytium) have been identified using vigorous gene expression analysis tools. We are currently cloning all of these genes (13) in virus induced gene silencing (VIGS) vector and overexpression vector to quantify the impact of reducing and increasing the expression level of these genes on soybean susceptibility/resistance to SCN infection using VIGS and transgenic hairy root systems. In addition, in order to profile DNA methylation patterns at genome level of soybean roots during the susceptible interaction with SCN, we inoculated soybean cultivar William 82 with SCN and root tissues were collected at 4 day after inoculation from both infected and non-infected soybean plants. The experiment was repeated three time each with thee biological replicates. We then developed an efficient methodological framework for construction of whole genome bisulfite-treated DNA libraries to map DNA methylation at single nucleotide resolution. Two libraries from infected and non-infected soybean roots heave been successfully generated and used for Illumina high-throughput sequencing with a 20X coverage anticipation. Different patterns of DNA methylation (CG, CHG and CHH) will be mapped to soybean genome to identify genomic loci and the corresponding genes that are subjected to specific modifications associated with differential response of soybean to plants to SCN infection. <br /> <br /> (Virginia) Charles Johnson and J. D. Eisenback: Meloidogyne incognita, M. arenaria, and M. javanica are the most important nematodes affecting the production of tobacco around the world. Historically Meloidogyne incognita been the most common root-knot nematode species in Virginia, however, because most commercial varieties contain a resistance gene to races 1 and 3 of M. incognita (Rk1), M. arenaria is rapidly becoming the most important pathogen in Virginia and probably other states as well. M. arenaria comprised 41% of the root-knot populations a 2006 survey, and 58% in a 2010 survey. Resistant cultivars to M. arenaria and M. javanica, as well as, M. incognita, will be a useful tool to minimize the use of nematicides and limit crop reduction. Available tobacco cultivars are susceptible to attack by these two species root-knot. Resistant cultivars to M. incognita are homozygous with Rk1 alone, but some cultivars are homozygous for Rk1 and either homozygous or heterozygous for Rk2. This second gene for resistance was introduced into tobacco from a land race of N. tabacum in Zimbabwe. We are investigating the effect that homozygosity for both Rk1 and Rk2 has on the resistance to M. arenaria . Plant breeders are informed that utilizing both genes to improve tobacco germplasm can more effectively reduce crop losses caused by the root-knot nematodes.<br /> <br /> <br /> Objective 3: Facilitate and improve identification of nematode species and races. <br /> <br /> (Arkansas) R. T. Robbins: My student Marco Cordero and I investigated the morphological and molecular taxonomy of the Criconemoidea, a widespread and often damaging nematode group of over a dozen genera. The first 4 papers have been publication and 1 more has been submitted. During 2013, I found a species of Cyst nematode, Punctodera sp. My new graduate student, Churamani Khanal had a poster on new hosts of H. uriticae from Arkansas. He is also identified several populations of Root-knot to species used DNA sequences.<br /> <br /> T. R. Faske: My lab is setting up some basic molecular tools to use identify common nematode genera to species. Historically the widespread production of cotton across the state was a strong indicator that all the root-knot nematode in soil samples are M. incognita. Over the past few years there has been a decrease in cotton and increase in soybean, corn and peanut. Given this more diverse cropping system, lesion nematodes are becoming more common in soil samples thus speciation is needed to determine the most common species of Pratylenchus as well as the common species of Meloidogyne in Arkansas. Further, collaboration with Jeff Brady (Texas AgriLife Research, Stephenville, TX) resulted in the development of primers specific to M. gaminis. These primers are being tested among known several grass species of Meloidogyne at the Lonoke Extension Center.<br /> <br /> (Louisiana) A field study was conducted with two nutrient regimes (low fertility consisting of only N at 100 kg/ha and high fertility consisting of dolomitic lime at 2240 kg/ha, N at 100 kg/ha, P and K at 67.2 kg/ha, S at 9 kg/ha, B and Zn at 1.1 kg/ha) and four nematicide treatments (seed treatment with Avicta Complete Cotton, the fumigant 1,3-dichloropropene at 28.1 l/ha, combination of both nematicides, and a no-nematicide treatment) replicated 18 times. Application of 1,3-D or combined with Avicta Complete Cotton reduced southern root-knot by 57% or 78%, respectively compared to the no-nematicide. All of the nematicides significantly reduced reniform populations with the combination resulting in a reduction of 76% compared to the no-nematicide. There was a significant interaction between fertility and nematicides with a higher yield of Avicta Complete Cotton in the high fertility regime compared to the low fertility regime. The high fertility regime significantly enhanced yield of the Avicta Complete Cotton compared to the low regime. However, the high fertility regime was not important when 1,3-D was applied either alone or in combination with the seed treatment nematicide.<br /> <br /> Four 60-day-duration greenhouse studies were conducted to evaluate the effect of phosphorus (P), potassium (K) and sulfur (S) on reniform nematode (Rotylenchulus reniformis) pathogenicity and reproduction on cotton (Gossypium hirsutum). A soil mixture of 70.1% sand, 25.4% silt, and 2.5% clay and P, K, and S levels of 10, 20, 35, 60, and 73 mg kg-1; 44, 70, 106, 123, and 153 mg kg-1; and 3, 12, 20, 40, and 50 mg kg-1, respectively were employed in these studies. Application of P, but not K and S, produced a significant increase in plant shoot and root dry weights and resulted in a significant decrease in population levels of reniform nematode.<br /> <br /> In other 60 day greenhouse studies, the influence of soil texture on reproduction and pathogenicity of isolates of reniform nematode from Avoyelles, Evangeline, and Rapides parishes on the cotton cultivars Stoneville LA887, Stoneville 5288B2F, and Phytogen 375WF were evaluated. Soils with sand, silt, and clay contents ranging from 7.8 to 74.4, 20.7 to 66.3, and 4.9 to 25.9, respectively, were employed. Soil type had a significant effect on nematode reproduction on all three cotton cultivars. The interaction between soil type and reniform isolate significantly affected population densities of the three reniform isolates in each of the soil types for the Phytogen 375WF but not for either Stoneville LA887 or Stoneville 5288B2F. <br /> <br /> A survey was conducted to document plant parasitic nematode communities associated with centipede and St. Augustine turfgrasses in urban ecosystems in East Baton Rouge Parish, LA. Twelve nematode genera were identified from soil and root samples of St. Augustine lawns: Criconemella was found in 91%, Gracilicus in 3%, Helicotylenchus in 94%, Hemicycliophora in 2%, Hoplolaimus in 5%, Meloidogyne in 46%, Pratylenchus in 35%, Scutellonema in 2%, Trichodorus in 3%, Tylenchorhynchus in 25%, Tylenchus in 92% and Xiphinema in 15%. Respectively, average nematode densities per 250 cm3 of soil were 159, 20, 180, 11, 8, 54, 29, 11, 14, 25, 149, and 11. A total of 10 genera were identified from soil and root samples of centipede lawns; Criconemella were found in 86%, Helicotylenchus in 78%, Hoplolaimus in 25%, Meloidogyne in 25%, Pratylenchus in 69%, Scutellonema in 3%, Trichodorus in 14%, Tylenchorhynchus in 19%, Tylenchus in 92% and Xiphinema in 6%. Population densities per 250 cm3 of soil averaged 290, 186, 18, 52, 59, 25, 9, 32,132, and 14.<br /> <br /> <br /> (Mississippi) G. Lawrence: Soybean Cyst Nematode: Quantitative field testing Heterodera glycines from metagenomic DNA samples isolated directly from soil under agronomic production. Yan Li, G.W. Lawrence, V.P. Klink<br /> <br /> A quantitative PCR procedure targeting the Heterodera glycines ortholog of the Caenorhabditis elegans uncoordinated-78 gene determined their number from metagenomic DNA samples isolated directly from field soil under agronomic production. This outcome was in the presence of other soil dwelling plant parasitic nematodes including Hoplolaimus, predatory nematodes including Mononchus, free-living nematodes and biomass. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated directly from field soil.<br /> <br /> Figure 1. DNA amplification of a Hg-gene from different numbers of H. glycines (SCN) J2 in soil samples in greenhouse as shown by PCR and gel electrophoresis. Next used quantitative PCR to determine how the known counted number of nematodes added to a soil sample were reflected in quantitative PCR studies. As shown, the two results were very similar in their ability to measure the number of SCN in the soil.<br /> <br /> <br /> <br /> (North Carolina) Under the leadership of Dr. Weimin Ye (NCDA) with assistance from Steve Koenning a species of root-knot nematode new to North Carolina was discovered. Several new primers for species identification were developed.<br /> (South Carolina) Understanding the spatial distribution of reniform nematode in cotton fields is essential for the development of management strategies. Evidence suggesting that soil texture is one of the main factors driving distribution is somewhat contradictory. In this study, we examined the horizontal and vertical distribution of reniform nematode in two cotton fields in South Carolina, and measured potential correlations with soil texture. In the first field, forty samples were collected at random and separated into four depths: 0-15 cm, 15-30 cm, 30-60 cm, and below 60 cm. In the second field, eighty samples were collected representing four zones with different soil electrical conductivity readings and soil texture. Horizontal distribution analysis using the variance/mean ratios showed a significant clustered distribution at planting, mid-season, and harvest. However, a significant neighborhood structure was detected only in the field that was sampled at a finer scale (4 x 4 m) at harvest with patches between 8 and 18 square meters in two of the plots. Vertical distribution data showed the highest numbers of reniform nematode were found between 15- and 30-cm deep. Kriging analysis was used to predict reniform densities within each field/plot and revealed high levels of spatial variability at the three sampling dates. Correlations between reniform densities and soil texture were not observed. Knowledge of the spatial distribution of reniform nematode can lead to reduction of nematicide use in precision agriculture applications.<br /> Hoplolaimus stephanus is a poorly studied ecto-endoparasite of plants, fairly recently described and with few host reports. It is morphologically similar to H.galeatus, H.magnistylus and H.concaudajuvencus, sharing characters such as four incisures in the lateral lines, three esophageal gland nuclei, a hemizonid anterior to the excretory pore, and the presence of abundant males. Considering that the genetic diversity of H.stephanus is not well studied, it is possible that H.stephanus has wider range of distribution and hosts than reported. In this study, we examined the phylogenetic relationships of H. stephanus with morphologically similar species isolated from different hosts and locations in the United States. We used morphology and sequences of the mithocondrial DNA cytochrome oxidase c subunit I (COI) and the internal transcribed spacer 1 (ITS1) genes. The phylogenetic analysis of both genes showed clearly separated lineages for H.stephanus, H.magnistylus, H.concaudajuvencus, H.galeatus and 2 unidentified clades. New reports are provided for H. stephanus, H. magnistylus and H. concaudajuvencus in different states and hosts in the United States. We provide robust phylogenies of Hoplolaimus species of economic importance in the United States using nuclear and mitochondrial genes.<br /> <br /> (Virginia) A morphological description of the reniform nematode, Rotylenchulus reniformis has been initiated to describe details of the morphology and anatomy of this species. Both the light and scanning electron microscope are being utilized to examine this species. Two root-knot nematodes that are new to science are currently being named and described.<br /> <br /> Impact Statements:<br /> <br /> Until acceptable commercial cotton varieties are available a cotton-soybean (or other non-host) rotation is the most economically feasible method of reniform control. In cotton when uncontrolled the reniform nematode can reduce yield to the point where cotton production is not profitable. A good rotation, such as corn-cotton, sorghum-cotton or reniform resistant soybean-cotton can restore profitability to these infested fields. Rotation has an environmental advantage over chemical nematicides by having no long lasting effect on the field or crop and is environmentally safe to use. There are no detrimental human health concerns using rotations.<br /> <br /> This study will provide useful information for strategically deploying appropriate sources of SCN-resistance for managing SCN.<br /> <br /> Molecular techniques are identifying genes used in parasitic reaction by the Soybean Cyst Nematode. These will be useful in developing soybean varieties with resistance to this serious nematode pest.<br /> <br /> A molecular diagnostic technique for the soybean cyst nematodes will increase the accuracy of detecting the presence and quantification of these pests in the soil.<br /> <br /> Information about the presence of a new species of root-knot nematode in North Carolina and the need for additional control tactics is being disseminated through county extension meetings and the 2013 North Carolina Crop Protection School. The discovery of this nematode will necessitate the renewed search for resistant sources and the need for new nematode management tactics. <br /> <br /> This project was planned to acquire critical knowledge about the SCN infection process and the associated modification in the DNA or DNA-associated proteins of soybean in susceptible and resistant interactions. Genes with crucial roles in mediating plant susceptibility/resistance are known to be tightly controlled and that epigenetic modification of the DNA or its associated proteins is one of the most powerful mechanisms controlling gene expression and function. However, epigenetic control of gene expression in soybean is completely unknown. Because these modifications can affect what soybean genes are expressed and hence resistance, this information is essential to develop novel and durable resistance against this devastating parasite.<br /> <br /> The economics of production today and tomorrow demand the development of methods of identifying nematodes and formulating management tactics that are compatible with changing cropping preferences, production system technology and environmental concerns.<br /> <br /> Stacking genes for resistance to the root-knot nematode may increase the resistance response to this nematode and allow for the production of a crop in the presence of the nematode without selecting for more virulent races and species. <br /> <br /> Elucidating morphological details of the reniform nematode may discover useful characters to improve the identification of species within the genus Rotylenchulus. A detailed study of the morphology of this nematode has not been completed in the past and the scanning electron microsope has increase our understanding of the structural components that are present in the reniform nematode.<br /> <br /> Specialty melons including cantaloupe, honeydew, and Galia melons are extremely susceptible to root-knot nematodes (RKN). Since the ban of methyl bromide for pre-plant soil fumigation, which was previously the primary control method for RKN in melon, there has been an urgent need to develop alternative control methods for RKN in melon. Grafting melons and other cucurbits onto disease resistant rootstocks is commonly used in Asia, the Mediterranean, and Europe. However, the disease resistant rootstocks (bottle gourd and squash hybrids) commonly used for grafted melon and watermelon are highly susceptible to RKN. In greenhouse and field studies in Charleston, SC (USDA, ARS), African horned cucumber (Cucumis metulifer) accessions were identified which are highly resistant to root-knot nematodes. These highly resistant African horned cucumber accessions can be used for developing RKN-resistant rootstocks for grafted melon. RKN-resistant African horned cucumber rootstocks may be useful for managing RKN in specialty melons in the Southern U.S. <br /> <br />

Publications

Alabama<br /> Klink V. P., Matsye, P. D., Lawrence, K. K., Lawrence, G. W. Engineered soybean cyst nematode resistance. Intech Publishers. "Soybean - A Review / Book 1", ISBN 980-953-307-542-1<br /> <br /> Klink V. P., Lawrence, G. W., Lawrence, K. S. 2013. Engineered soybean cyst nematode resistance. Ch. 6: 139-172. in Soybean - Pest Resistance. Ed. HA El-Shemy. Intech Publishers. ISBN 978-953-51-0978-5.<br /> <br /> Castillo, J. D., Lawrence, K. S., and Kloepper, J. W. 2013. Biocontrol of the reniform nematode by Bacillus firmus GB-126 and Paecilomyces lilacinus 251 on cotton. Plant Disease 97:967-976.<br /> <br /> Moore, S. R. and K. S. Lawrence. 2013. The effect of soil texture and irrigation on Rotylenchulus reniformis I and cotton. Journal of Nematology 45:99-105.<br /> <br /> K. Vijay Krishna Kumar, S. KR. Yellareddygari, M. S. Reddy, J. W. Kloepper, K. S. Lawrence, M. E. Miller, H. Sudini, E.C. Surendranatha Reddy, X. G. Zhou and D. E. Groth. 2013. Ultrastructural studies on the interaction between Bacillus subtilis MBI 600 (Integral®) and the rice sheath blight pathogen, Rhizoctonia solani. African Journal of Microbiology Research Vol. 7:2078-2086.<br /> <br /> Seloame T. Nyaku, Ramesh V. Kantety, Yonathan Tilahun, Kathy S. Lawrence,<br /> Khairy M. Soliman, Ernst Cebert, and Govind C. Sharma. 2013. 18S and ITS1 Genomic Sequence Variations in Rotylenchulus reniformis Isolates from Alabama. The Journal of Cotton Science 17:184194.<br /> <br /> Nyaku S.T., Sripathi V.R., Kantety R.V., Gu Y.Q., Lawrence K., et al. (2013) Characterization of the Two Intra-Individual Sequence Variants in the 18S rRNA Gene in the Plant Parasitic Nematode, Rotylenchulus reniformis. PLoS ONE 8(4): e60891. doi:10.1371/journal.pone.0060891.<br /> <br /> Bennett, Rebecca S., Tamara Z. Scott, Katheryn S. Lawrence, and Gary W. Lawrence. 2013. Sequence characterization of race 4-like isolates of Fusarium oxysporum from Alabama and Mississippi. Journal of Cotton Science 17:1-6.<br /> <br /> 60. Wheeler, T. A., K. S. Lawrence, D. O. Porter, W. Keeling, and B. G. Mullinix, Jr. 2013. The relationship between environmental variables and response of cotton to nematicides. Journal of Nematology 45: 8-16. <br /> <br /> <br /> Lawrence, K. S. and G. W. Lawrence. 2013. Holistic Crop Management Systems in Reniform Nematode Infected Fields. Proceeding of the XXXI Congress of Brazilian Nematology Vol.1:33-34.<br /> <br /> Lawrence, K. S., C. D. Monks, and D. Delaney. Eds. 2012 AU Crops: Cotton Research Report. March 2013. Alabama Agricultural Experiment Station Research Report Series No. 42. http://aurora.auburn.edu/repo/bitstream/handle/11200/44167/CottonResearchReport2012.pdf?sequence=2<br /> <br /> Wallace, Ted P., P. M. Thaxton, Bobby Golden, G. W. Lawrence, Jodi Scheffler, K. S Lawrence, David Weaver and Roelof B. Sikkens. 2013. Agronomic Performance of Barbadense and Longicalyx Derived Breeding Lines. Proceedings of the Beltwide Cotton Conference, Vol. 1:1005. National Cotton Council of America, Memphis, Tennessee. http://www.cotton.org/beltwide/proceedings/2005-2013/index.html<br /> <br /> Rothrock C. S., S. A. Winters, J.D. Barham, Alan B. Beach, Melanie B. Bayles, P. D. Colyer, T. Kelley, R. C. Kemerait, G.W. Lawrence, K. S. Lawrence, G.B. Padgett, P. M. Phipps, G. L. Sciumbato, R. Thacker, and J. E. Woodward. 2013. Report of the Cottonseed Treatment Committee for 2012. Proceedings of the Beltwide Cotton Conference, Vol. 1:157-164. National Cotton Council of America, Memphis, Tennessee. http://www.cotton.org/beltwide/proceedings/2005-2013/index.html<br /> <br /> Smith, Randy, Gary W. Lawrence, Kathy S. Lawrence, Richard Harkess and Carolyn Conger. 2013. Growth and Development of Five Upland Cotton (Gossypium hirsutum) Varieties in Reniform (Rotylenchulus reniformis) Infested Soils. Proceedings of the Beltwide Cotton Conference, Vol. 1:123-128. National Cotton Council of America, Memphis, Tennessee. http://www.cotton.org/beltwide/proceedings/2005-2013/index.html<br /> <br /> Castillo, J.D., D. Schrimsher, and K. Lawrence. 2012. Effect of Bacillus firmus GB-126 against Rotylenchulus reniformis, Meloidogyne incognita, and Heterodera glycines under in vitro and greenhouse conditions. Journal of Nematology 44: 456-457.<br /> <br /> Lawrence, K.S., D.W, Schrimsher, and Chet Norris. 2013. Fungicide combination evaluations for cotton seedling disease management in north Alabama, 2012. Report 7: ST011. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> Lawrence, K.S., D.W, Schrimsher, C. H. Burmester, and Chet Norris. 2013. Seed quality and fungicides combinations for seedling disease management in north Alabama, 2012. Report 7: ST010. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> Lawrence, K.S., D.W, Schrimsher, C. H. Burmester, and Chet Norris. 2013. Cotton variety and nematicide combinations for reniform management in north Alabama, 2012. Report 7: N014. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> Lawrence, K.S., D.W, Schrimsher, and S. Nightengale. 2013. Cotton variety and nematicide combinations for root knot management in south Alabama, 2012. Report 7: N013. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> Lawrence, K.S., D.W, Schrimsher, C. H. Burmester, and Chet Norris. 2013. Cotton seed treatment, granular, and foliar nematicide combinations for reniform management in north Alabama, 2012. Report 7: N012. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> Lawrence, K.S., D.W, Schrimsher, and S. Nightengale. 2013. Cotton seed treatment, granular and foliar nematicide combinations for root knot management in Alabama, 2012. Report 7: N011. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> Schrimsher, D.W, and K.S. Lawrence. 2013. Evaluation of Aeris, Temik, and two experimental compounds for management of reniform nematodes on cotton in north Alabama, 2012. Report 7: N008. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> Schrimsher, D.W, and K.S. Lawrence. 2013. Evaluation of Poncho Votivo, Aeris, and Temik on cotton for reniform nematode management in north Alabama, 2012. Report 7: N007. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> N. Xiang, K.S. Lawrence, D. Schrimsher, and S. Nightengale. 2013. Evaluation of Temik, Aeris, and two experimental compounds on cotton for root knot management in Alabama, 2012. Report 7: N006. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> N. Xiang, K.S. Lawrence, D. Schrimsher, and S. Nightengale. 2013. Evaluation of Poncho Votivo, Aeris, Temik, and UFS0 738 on cotton for root knot management in Alabama, 2012. Report 7: N005. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> Bailey, David, K. S. Lawrence, and D. S. Schrimsher. 2013. Valent soybean seed treatment evaluation for reniform management in north Alabama, 2012. Report 7: N004. DOI:10.1094/PDMR07. The American Phytopathological Society, St. Paul, Minnesota.<br /> <br /> Bailey, David, K. S. Lawrence, and D. S. Schrimsher. 2013. Evaluation of seed treatment nematicides on soybeans for reniform management in north Alabama, 2012. Report 7: N003. DOI:10.1094/PDMR07. The American Phytopathological Society, St. Paul, Minnesota.<br /> <br /> Bailey, David, K. S. Lawrence, and D. S. Schrimsher. 2013. Soybean variety response to reniform nematodes in north Alabama, 2012. Report 7: N002. DOI:10.1094/PDMR07. The American Phytopathological Society, St. Paul, Minnesota.<br /> <br /> Bailey, David, K. S. Lawrence, and D. S. Schrimsher. 2013. Evaluation of seed treatment nematicides on soybeans for root knot management in central Alabama, 2012. Report 7: N001. DOI:10.1094/PDMR07. The American Phytopathological Society, St. Paul, Minnesota.<br /> <br /> (ARKANSAS)<br /> Cordero, Marco. A., Robert T. Robbins, Allen L. Szalanski. 2012. Taxonomic and Molecular Identification of Mesocriconema and Criconemoides Species (Nematoda: Criconematidae). Journal of Nematology 44:399426.<br /> <br /> Cordero, Marco. A., Robert T. Robbins, Allen L. Szalanski. 2012. Taxonomic and Molecular Identification of Hemicaloosia, Hemicycliophora, Gracilacus And Paratylenchus Species (Nematoda: Criconematidae). Journal of Nematology (In Press).<br /> <br /> Cordero, Marco. A., Robert T. Robbins, Allen L. Szalanski. 2012. Molecular Based-Phylogenetic Relationships In The Superfamily Criconematoidea. Nematropica<br /> Reyes Peña-Santiago , Joaquín Abolafia, Sergio Álvarez-Ortega,Weimin Ye and Robert T. Robbins. 2013. Axonchoides smokyensis sp. n. (Dorylaimida: Belondiridae) from the Great Smoky Mountains National Park; the second species of a very rare genus. Nematology 11:1-15 <br /> <br /> Chen, P., J.C. Rupe, D.G. Dombek, T. Kirkpatrick, R.T. Robbins, C. Wu, and P. Manjarrez. 2013. Registration of UA 5213C Soybean. Journal of Plant Registrations (In Press).<br /> <br /> R. T. Robbins, E. Shipe, G. Shannon, P. Chen, S. K. Kantartzi, L. E. Jackson, E. E. Gbur, D. G. Dombek, and J. T. Velie. 2013. Reniform Nematode Reproduction on Soybean Cultivars and Breeding Lines in 2012. Proceeding of the 2013 Beltwide Cotton Conferences, San Antonio, Texas, January, 2012. Pgs. 129-137.<br /> <br /> R. T. Robbins, E. Shipe, G. Shannon, P. Chen, S. K. Kantartzi L. E. Jackson, E. E. Gbur, D. G. Dombek, and J. T. Velie. 2013. Reniform Nematode Reproduction on Soybean Cultivars and Breeding Lines in 2012. Program of the 2013 Beltwide Cotton Conferences, San Antonio.<br /> <br /> Robbins, R. T., 2013. A History of the Reniform Nematode in the South. Southern Soybean Disease Workers, March, 14 2013.<br /> <br /> Cordero, Marco A. and R. T. Robbins. 2013. Taxonomic identification of species of Criconematidae from the permanent slide collection of R. T. Robbins. Society of Nematology Knoxville Meetings Program. Pg. 40.<br /> <br /> Khanal, C. and R. T. Robbins. 2013. Expanded host range of Heterodera urticae from Arkansas. Society of Nematology Knoxville Meetings Program. Pg. 39-40.<br /> <br /> (LOUISIANA)<br /> <br /> Magalhães, D. X., C. Overstreet, E. C. McGawley, M. T. Kularathna, and C. M. Martin. 2013. The Influence of Commerce Silt Loam Soil Texture on Reproduction and Pathogenicity of Rotylenchulus reniformis on Cotton. Journal of Nematology; In press.<br /> <br /> Plaisance, A.R., E.C. McGawley, C. Overstreet, and Y. Takeuchi. 2013. Species Abundance and Influence of Nematodes in Urban Turf grass Ecosystems in East Baton Rouge Parish, LA. Journal of Nematology; In press.<br /> <br /> McGawley, E.C. and C. Overstreet. 2013. Introduction to Nematodes, A multimedia Presentation for Teaching Nematology. Nematropica; In press.<br /> <br /> Overstreet, C., E. C. McGawley, D. M. Xavier, M. T. Kularathna, C. M. Martin and R.A. Haygood. 2013. Nutrient Enhancement of Nematicides in Cotton with Concomitant Infestation of Meloidogyne incognita and Rotylenchulus reniformis. Journal of Nematology; In press<br /> <br /> Kularathna, M. T., C. Overstreet, E. C. McGawley, D. M. Xavier and C. M. Martin. 2013. Influence of soil nutrients on reproduction and pathogenicity of Rotylenchulus reniformis on Cotton. Nematropica: in press.<br /> <br /> (MINNESOTA)<br /> <br /> Chen, S. 2012. Impact of tillage and source of resistance on dynamics of the soybean cyst nematode population and its virulence phenotype. Journal of Nematology 44:457.<br /> <br /> (MISSISSIPPI)<br /> <br /> Klink, V.P., G.W. Lawrence and K.S. Lawrence 2013 Engineered soybean cyst nematode resistance, Ch 6: 139-172. In Soybean  Pest Resistance, Ed: HA EL-Shemy, Intech Publishers ISBN 978-953-51-0978-5<br /> <br /> Klink VP, Matsye PD, Lawrence KK, Lawrence GW. Engineered soybean cyst nematode resistance. Intech Publishers. "Soybean - A Review / Book 1", ISBN 980-953-307-542-1. <br /> <br /> Bennett, Rebecca S., Tamara Z. Scott, Katheryn S. Lawrence, and Gary W. Lawrence. 2013. Sequence characterization of race 4-like isolates of Fusarium oxysporum from Alabama and Mississippi. Journal of Cotton Science 17:1-6.<br /> <br /> Lawrence, K. S. and G. W. Lawrence. 2013. Holistic Crop Management Systems in Reniform Nematode Infected Fields. Proceeding of the XXXI Congress of Brazilian Nematology Vol.1:33-34.<br /> <br /> Wallace, Ted P., P. M. Thaxton, Bobby Golden, G. W. Lawrence, Jodi Scheffler, K. S Lawrence, David Weaver and Roelof B. Sikkens. 2013. Agronomic Performance of Barbadense and Longicalyx Derived Breeding Lines. Proceedings of the Beltwide Cotton Conference, Vol. 1:1005. National Cotton Council of America, Memphis, Tennessee. http://www.cotton.org/beltwide/proceedings/2005-2013/index.html<br /> <br /> Rothrock C. S., S. A. Winters, J.D. Barham, Alan B. Beach, Melanie B. Bayles, P. D. Colyer, T. Kelley, R. C. Kemerait, G.W. Lawrence, K. S. Lawrence, G.B. Padgett, P. M. Phipps, G. L. Sciumbato, R. Thacker, and J. E. Woodward. 2013. Report of the Cottonseed Treatment Committee for 2012. Proceedings of the Beltwide Cotton Conference, Vol. 1:157-164. National Cotton Council of America, Memphis, Tennessee. http://www.cotton.org/beltwide/proceedings/2005-2013/index.html<br /> <br /> Smith, Randy, Gary W. Lawrence, Kathy S. Lawrence, Richard Harkess and Carolyn Conger. 2013. Growth and Development of Five Upland Cotton (Gossypium hirsutum) Varieties in Reniform (Rotylenchulus reniformis) Infested Soils. Proceedings of the Beltwide Cotton Conference, Vol. 1:123-128. National Cotton Council of America, Memphis, Tennessee. http://www.cotton.org/beltwide/proceedings/2005-2013/index.html<br /> <br /> (NORTH CAROLINA) <br /> <br /> Koenning, S. R. 2013. A critical evaluation of cotton tolerance to Hoplolaimus Columbus. Programs and Abstracts of the XLV Annual Meeting, La Serena, Chile 2013.<br /> <br /> Ye, W.M., S. R. Koenning, K. Zhuo, and J. L. Liao. 2013. First Report of Meloidogyne enterolobii on Cotton and Soybean in North Carolina, United States. Plant Disease 97:1262.<br /> <br /> Xue, B., N. Hamamouch, C. Li, G. Huang, R.S. Hussey, T.J. Baum, and E.L. Davis. 2013. The 8D05 parasitism gene of Meloidogyne incognita is required for successful infection of host roots. Phytopathology 103:175-181.<br /> <br /> Mitchum, M.G., Hussey, R.S., Davis, E.L., Baum, T.J., Wang, X., Elling, A.A., Wubben, M. 2013. Tansley Review: Nematode effector proteins: an emerging paradigm of parasitism. New Phytologist 199:879-894.<br /> <br /> (MISSISSIPPIS - USDA) <br /> <br /> Adams, L., R. G. Luttrell, and S. R. Stetina. 2013. Product evaluation for reniform nematode suppression in Mississippi delta sweetpotato production, 2011. Report no. 7:N020. Online. Plant Disease Management Reports. doi:10.1094/PDMR07.<br /> <br /> Molin, W. T., and S. R. Stetina. 2013. Responses of reniform nematode and browntop millet to tillage, cover crop, and herbicides in cotton. Online. Crop Management. doi:10.1094/CM-2013-0428-01-RS.<br /> <br /> Erpelding, J. E., and S. R. Stetina. 2013. Genetics of reniform nematode resistance in Gossypium arboreum germplasm line PI 529728. World Journal of Agricultural Research 1:48-53.<br /> <br /> (SOUTH CAROLINA)<br /> <br /> Jagdale, Ganpati B., T. Holladay, P. M. Brannen, W.O. Cline, P. Agudelo, A. P. Nyczepir and J. P. Noe. 2013. Incidence and pathogenicity of plant-parasitic nematodes associated with blueberry (Vaccinium spp.) replant disease in Georgia and North Carolina. Journal of Nematology 45:92-98<br /> <br /> Donald, P., C. M. Holguin, P.Agudelo. 2013. First Report of Lance Nematode (Hoplolaimus magnistylus) on Corn, Soybean and Cotton in Tennessee. Plant Disease 97:1398<br /> <br /> Shaver, J. P. Agudelo, and S. B. Martin. 2013. First Report of Stubby Root Caused by Trichodorus obtusus on Zoysiagrass and Bermudagrass in South CarolinaPlant Disease 97: 852<br /> <br /> (SOUTH CAROLINA - USDA)<br /> <br /> Fery, R.L. and J.A.Thies. PA-566, a root-knot nematode resistant, pimento-type pepper. HortScience 46(4):668-669. 2011. <br /> <br /> Fery, R.L. and J.A.Thies. Truhart-NR, a root-knot nematode resistant, pimento-type pepper. HortScience 46(5):815-816. 2011. <br /> <br /> Fery, R.L. and J.A.Thies. PA-560, a southern root-knot nematode resistant, yellow-fruited, habanero-type pepper. HortScience 46(6):647-947. 2011. <br /> <br /> Guan, W., X. Zhao, R. Hassell, and J. Thies. Defense mechanisms involved in disease resistance of grafted vegetables. HortScience 47(2):164-170. 2012. <br /> <br /> Levi, A., Thies, J., W. Wechter, H. Harrison, A. Simmons, U. Reddy, P. Nimmakayala, and Z. Fei. High frequency oligonucleotides - targeting active gene (HFO-TAG) markers reveal wide genetic diversity among Citrullus spp. accessions useful for enhancing disease or pest resistance in watermelon cultivars. Genetic Resources and Crop Evolution DOI 10.1007/s10722-012-9845-3. 2012. <br /> <br /> Levi, A., W.P. Wechter, J.A.Thies, K. Ling, and U. Reddy. 2012. Genetics, Genomics and Breeding of Watermelon. CRC Press. Print-ISBN: 978-1-57808-766-2; eBook-ISBN: 978-1-4398-8807-0. pp. 309-334. (Book Chapter) <br /> <br /> Thies, J.A., .J. Ariss, R. Hassell, C.S. Kousik, S. Olsen., A. Levi. 2010. Grafting for managing southern root-knot nematode, Meloidogyne incognita, in watermelon. Plant Disease. 94:1195-1199<br /> <br /> Thies, J.A. Virulence of Meloidogyne incognita to expression of N gene in pepper. Journal of Nematology 43(2):90-94. 2011. <br /> <br /> <br /> (VIRGINIA)<br /> <br /> Mallez, Sophie, Chantal Castagnone, Margarida Espada, Paulo Vieira, Jonathan Eisenback, Manuel Mota, Thomas Guillemaud, Philippe Castagnone-Sereno. 2013. First insights into the genetic diversity of the pinewood nematode in its native area using new polymorphic microsatellite loci. PLOS ONE 8:1-8.<br /> <br /> Eisenback, J. D., Wei, Ma, and C. W. Roane. 2013. Heat tolerance and aging of the anhydrobiotic seed gall nematode, Anguina agrostis with SEM observations. Journal of Nematology 45:43-48.<br /> <br /> Parkunan, V., C. S. Johnson and J. D. Eisenback. 2013. Induction and maintenance of systemic acquired resistance by acibenzolar-S-methyl in cultivated tobacco. Plant Disease 04/2013.<br /> <br /> Holshouser, David, Jon Eisenback, Pat Phipps, and David Moore. 2012. Soybean Nematode Management Guide. VCE Pub. AREC-1.<br /> <br /> Phipps, P. M., and J. D. Eisenback. 2012. Susceptibility of cotton varieties to root-knot nematode and their response to Temik 15G in-furrow, 2012. Plant Disease Management Reports 6:N004<br /> <br /> Phipps, P. M., and J. D. Eisenback. 2012. The comparison of cotton seed and in-furrow treatments for control of nematodes, 2012. Plant Disease Management Reports 6:N004<br /> <br /> Phipps, P. M., and J. D. Eisenback. 2012. Response of peanut cultivars to Proline, Propulse, and Sectagon-42 for disease control in peanut, 2012. Plant Disease Management Reports 6:N003<br /> <br /> Askew, S D., Eisenback, J. D., M. Goatley, Jr., R. D. Grisso, P. L. Hipkins, D. S. McCall, and R. R. Youngman. 2012. Turf Pest Control: A Guide for Turf Managers in Virginia. Virginia Cooperative Extension publication 346.<br /> <br /> P. M. Phipps, Darcy Telenko, and J. D. Eisenback . 2012. The response of cotton varieties to Temik 15G in-furrow, Plant Disease Management Reports 5:N003.<br /> <br /> P. M. Phipps, Darcy Telenko, and J. D. Eisenback . 2012. The response of cotton to seed treatments for control of southern root-knot nematode. Plant Disease Management Reports 5:N001.<br /> <br /> P. M. Phipps, Darcy Telenko, and J. D. Eisenback . 2012. The response of cotton to foliar applications of CMT4856 and Temik in-furrow, Plant Disease Management Reports 5:N002<br /> <br /> Johnson, Charles, Jonathan Eisenback, David Reed, Stephen Barts and Taylor C. Clarke. 2012. Progress report on, "Continuation of "Assessing populations of Meloidogyne species in Virginia's flue-cured tobacco fields". Virginia Bright Flue-Cured Tobacco Board<br />

Impact Statements

1. " A good rotation, such as corn-cotton, sorghum-cotton or reniform resistant soybean-cotton, can restore profitability to reniform infested fields and has no long lasting effect on the field or crop because it is environmentally safe.
2. " Molecular techniques are identifying genes used in parasitic reaction by the soybean cyst nematode that will be useful in developing soybean varieties with resistance to this serious nematode pest.
3. " A molecular diagnostic technique for the soybean cyst nematodes will increase the accuracy of detecting the presence and quantification of these pests in the soil.
4. " The discovery of Meloidogyne enterolobii in North Carolina will necessitate the renewed search for resistant sources and the need for new nematode management tactics.
5. " Acquisition of critical knowledge about the soybean cyst nematode infection processes and the associated modifications in the DNA or DNA-associated proteins of soybean in susceptible and resistant interactions, can affect genes that are expressed in resistant plants and are essential information needed to develop novel and durable resistance against this devastating parasite.
6. " The economics of production demand the development of methods of identifying nematodes and formulating management tactics that are compatible with changing cropping preferences, production system technology, and environmental concerns.
7. " Stacking genes for resistance to the root-knot nematode may increase the resistance response to this nematode and allow for the production of a crop in the presence of the nematode without selecting for more virulent races and species.
8. " Elucidating morphological details of the reniform nematode may discover useful characters to improve the identification of species within the genus Rotylenchulus.
9. " Disease resistant rootstocks (bottle gourd and squash hybrids) commonly used for grafted melon and watermelon are highly susceptible to root-knot nematodes (RKN); however, African horned cucumber rootstocks are resistant and may be useful for managing RKN in specialty melons in the southern U.S.
10. " Grain sorghum varieties useful for management of Meloidogyne incognita have been identified.
11. " Several factors determining reniform nematode distribution in the field were identified
12. " Characterization of poorly studied Hoplolaimus stephanus populations in the United States were made so that this species can be better recognized as a major pest of crop plants.

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Report Information

Participants

Paula Agudelo (SC)
Don Dickson (FL)
Jon Eisenback (VA)
Travis Faske (AR)
Tarek Hewezi (TN)
Charles Johnson (VA)
Gary Lawrence (MS)
Kathy Lawrence (AL)
Charlie Overstreet (LA)
Hillary Mehl (VA)
Ron Lacewell (Administrative Advisor for S-1046, TX)
Graduate students attending included Brandon McNeece (MS), Keshav Sharma (MS), Hollis Rice (TN), Vanessa Paes-Takanasha (VA), Jill Pollok (VA).

Brief Summary of Minutes

Sept. 17-18, 2014
This meeting was organized by Jon Eisenback and Chuck Johnson (VA)
Sept. 17, 2014
The meeting was convened at 8:00 am at the Williamsburg Welcome Center, Williamsburg, VA. We began with registration and welcoming remarks by Jon Eisenback.

Scientists in attendance (and the state they represent) were: Paula Agudelo (SC), Don Dickson (FL), Jon Eisenback (VA), Travis Faske (AR), Tarek Hewezi (TN), Charles Johnson (VA) Gary Lawrence (MS), Kathy Lawrence (AL), Charlie Overstreet (LA), Hillary Mehl (VA), Ron Lacewell (Administrative Advisor for S-1046, TX). Graduate students attending included Brandon McNeece (MS), Keshav Sharma (MS), Hollis Rice (TN), Vanessa Paes-Takanasha (VA), Jill Pollok (VA).
Jon Eisenback welcomed the group and organized the meeting schedule. Ron Lacewell gave an update on our status of the report need in 60 days and well as our minutes from the meeting. Our new project must be completed and he will submit it. Our focus of this meeting is the development of our new project.
Report started with the graduate students presenting their research. Brandon McNeece (MS), Keshav Sharma (MS), Vanessa Paes-Takanasha (VA), and Jill Pollok (VA) all presented their finding from their nematology research.
Members including Paula Agudelo (SC), Don Dickson (FL), Jon Eisenback (VA), Travis Faske (AR), Tarek Hewezi (TN), Charles Johnson (VA) Gary Lawrence (MS), Kathy Lawrence (AL), Charlie Overstreet (LA), Hillary Mehl (VA), Ron Lacewell (Administrative Advisor for S-1046, TX) separated into three groups and began the writing of the new project.
New S1046 project title: "Development of sustainable crop production practices for integrated management of plant-pathogenic nematodes."
Objective 1 = Integrate biological and cultural management tactics with the use of resistant cultivars to develop sustainable crop production systems.
Objective 2 = Elucidate molecular and physiological mechanisms of plant-nematode interactions to improve host resistance.
Objective 3 = Advance the tools for identification of nematode species and characterization of intraspecific variability.

Members began their oral reports Friday morning. Reports were presented by Kathy Lawrence (Auburn University), Travis Faske (University of Arkansas), Don Dickson (University of Florida), Charlie Overstreet ( Louisiana State University), Gary Lawrence (Mississippi State University), Paula Agudelo (Clemson University), Tarek Hewezi (University of Tennessee), with Jon Eisenback and Chuck Johnson (Virginia Ploy Tech).
At the business meeting the minutes from 2013 were moved as accepted and the motion was approved by all in attendance. The next meeting will be held the last week of Oct. or the first week of Nov. in 2015 in Alabama with Kathy Lawrence hosting the meeting. It was proposed by K. Lawrence (AL) that we meet with members of the W-3186 Multi-State group in 2015. In further discussions, K. Lawrence will serve as chair the 2015 annual meeting and T. Hewezi (TN) will serve as secretary. Tarek Hewezi volunteered to host the meeting in Tennessee in 2016.
Chuck Johnson, as the chair of the proposal summarized our writing. Chuck will review our work from yesterday and will return it to us to add and review. Pat Donald, Ernie Bernard, Greg Tylka, and Janette Brito were recommended as reviewers for our proposal.
Kathy Lawrence requested all members to send her bullet points and accomplishments as soon as possible in order to get the final report complete and approved with in the 60 days are required.
The 2014 annual meeting of the S-1046 Multistate Research Project was adjourned Sept. 18, 2014 at 11:55 am.

Accomplishments

Objective 1: Integrate resistant cultivars with other nematode management tactics to reduce selection pressure on nematode populations and communities. <br /> (Alabama, K. Lawrence) Fusarium wilt (Fusarium oxysporum f. sp. vasinfectum, “FOV”) is a serious disease of cotton, and is intensified by the presence of root-knot nematodes (Meloidogyne incognita). Twelve cultivars were monitored for Fusarium wilt resistance in addition to susceptible (Rowden) and resistant (M-315) checks at the E. V. Smith Research Center, Plant Breeding Unit, near Tallassee, Alabama. The test was established in a RCBD with four replications. The Fusarium wilt disease pressure was mild in 2013. The susceptible check Rowden had an average of 11.8% wilt, with the lowest amount of disease being 7.5% and the most disease observed was 18.1%. Ten cultivars displayed fewer Fusarium wilt symptoms than Rowden, including Croplan Genetics 3787 B2RF, Deltapine 1137 B2RF, Deltapine 12R242B2R2, Deltapine 1321 B2RF, FiberMax1944 GLB2, Phytogen 339 WRF, Phytogen 375 WRF, Phytogen 499 WRF, Stoneville 4946 GLB2, and Stoneville 6448 GLB2. Seven cultivars had statistically similar wilt percentages to the resistant check M-315. The lowest wilt percentages observed were FiberMax 1944 GLB, Phytogen 339 WRF, Stoneville 4946 GLB2, Phytogen 499 WRF, and Stoneville 6448 GLB2 with 0.3%, 0.3%, 0.8%, 0.9%, 0.9%, and 0.9% percent wilt, respectively. <br /> The susceptible check Rowden had an average of 510 root-knot nematode eggs per gram of root fresh weight (eggs/g RFW), with a range of 256 to 1016 eggs/g RFW. The resistant check M-315 had an average of 86 eggs/g RFW, and supported a range of only 43 to 170 eggs/g RFW. Two varieties were supported more root knot nematodes than the resistant check M-315: Phytogen 339 WRF and Phytogen 375 WRF, with averages of 681 and 602 eggs/g RFW, respectively. No varieties were statistically lower than the susceptible check Rowden, but two varieties supported only 111 eggs/g RFW; Deltapine 12R242B2R2 and FiberMax 1944 GLB2. <br /> The susceptible cultivar Rowden yielded an average of 1963 lbs of seed cotton per acre, with a range of 759 to 3167 lbs per acre. At 0.85¢ per pound (the average price of cotton lint in December 2013) the average profit per acre would be $667. The resistant check M-315 yielded an average of 2994 lbs of seed cotton per acre, with a range of 1789 to 4198 lbs per acre. The average profit per acre for M-315 would be $1018. Three varieties were statistically higher yielding than the susceptible check Rowden: FiberMax 1944 GLB2, Phytogen 339 WRF, and Phytogen 499 WRF with 5300, 4712, and 4806 lb. averages per acre of seed cotton yield. FiberMax 1944 GLB2 profited $1802 per acre, Phytogen 339 WRF $1602 per acre, and Phytogen 499 WRF $1634 per acre. The highest yielding cultivar, FiberMax 1944 GLB2, produced an average of $1135 more in profits than the susceptible check Rowden. This represents how imperative it is to be selective of the cultivar grown.<br /> FOV races 1, 8, LA 110, LA 108, LA 127, and LA 140 were all found in the susceptible Rowden variety. Only FOV races 1 and 8 were isolated from the resistant standard line M-315. The cotton varieties from Deltapine, Phytogen, Stoneville and Croplan were all found to be colonized with FOV race 1 which was the most common race during the 2013 season. 45% of the FOV isolates were determined to be race 1. 32.5% of the FOV isolates were identical to LA 108. Race 8 constituted 12.5 % of FOV isolates and 2.5% were identified as LA 110. Three isolates were similar to LA 127 and LA 140. Races 3, 4, and LA 112 were not isolated from the Fusarium wilt symptomatic cotton plants in the 2013 trial. LA isolates were recently identified and sequenced by Holmes et al. (2009) and are believed to have originated from Louisiana. No race 4 isolates were identified in the 2013 Commercial Cotton Variety Trial in Alabama. Races 3 and LA 112 had also been identified in previous years and until the 2013 season only LA 110 and LA 112 of the Louisiana isolates had been identified. The location of the trial has been the same for many years, and these molecular results confirm that numerous FOV races are present in the same field. <br /> (Arkansas, R. T. Robbins) In a field with a high population of race 5 SCN on the Marianna Experiment station a planted for a second year in a 3 year soybean rotation cycle in which susceptible, moderately resistant and very resistant varieties were planted. At planting the plots following susceptible averaged 937eggs per 100 ML soil, the moderately resistant averaged 711 eggs and the very resistant averaged 405 eggs.<br /> I am testing 184 soybean entries new to the Arkansas Soybean Variety Testing program soybean. Entries with resistance could be useful in a cotton-soybean rotation to reduce numbers. Also tested were 199 lines from Southern Soybean Breeders (5 from USDA Jackson TN (Arelli), 69 from Arkansas (Chen); 12 from Clemson, (Fallen), 14 from Missouri (Shannon; and 99 from Southern Illinois – Carbondale (Kartanzi), for resistance to the reniform nematode (Rotylenchulus reniformis) in soybean. <br /> <br /> (Arkansas, T. R. Faske) Twelve commercially available soybean varieties were evaluated for resistance to the southern root-knot nematode in a commercial field. A few group V varieties expressed a moderate level of resistance to RKN. <br /> My program has investigated the nematicidal activity of fluopyram, an SDHI fungicide, in several in-vitro nematode sensitivity assays. We determined the sensitivity of RKN and RN to fluopyram was similar to that of aldicarb. Sub-lethal concentrations of fluopyram impeded RKN and RN ability to infect tomato roots. Some recovery was observed for each nematode species once fluopyram was washed and removed for 24 hr., which indicates nematistatic activity of fluopyram. These data document the unique activity of fluopyram and its potential in the integrated management of plant-parasitic nematodes. <br /> <br /> (Mississippi, G.W. Lawrence) Emergence of new nematicidal products. Several agricultural chemical companies are in the process of developing products designed for nematode control in row and vegetable crops (Table 1). Efficacy studies have been conducted with these products to determine their effect on nematode infestations of field crops.<br /> <br /> Table 1. Experimental and Existing Nematicidal Product by Company, Product and Application Method<br /> <br /> Company Product Application<br /> <br /> ADAMA MCW-2 – NIMITZ (fluensulfone) In-furrow spray<br /> AMVAC Counter 20G (Terbufos) In-furrow granular<br /> Thimet (Phorate) In-furrow granular<br /> Bayer Velum Total (Fluopyram + Imidacloprid) In-furrow spray<br /> Aeris seed applied system (Thiodicarb) Seed treatment<br /> Votivo (Bacillis firmis) Seed treatment <br /> DuPont Vydate L (Oxamyl) In-furrow spray<br /> Vydate C-LV (Oxamyl) Foliar spray<br /> Q8U80 In-furrow spray<br /> Monsanto Numbers (1-14) Seed treatment<br /> Marrone MBI- 38 In-furrow spray<br /> NuFarm Azadirachtin, Nematox, Senator Seed treatment<br /> Neem Oil, albendazole, Imidacloprid <br /> Syngenta Avicta Complete (abamectin) Seed treatment<br /> <br /> (North Carolina, S. Koenning) Experiments evaluating the potential for temporal and spatial deployment of soybean cyst nematode resistance were terminated. A demonstrated potential for both approaches has been proven to delay development or resistance breaking biotypes of cyst nematode. A number of viruses have been detected in soybean cyst nematode. In fact all populations in North Carolina tested thus far have detectible viral RNA. This discovery may lead to improved methods for management of this pest. <br /> The functions and plant targets of several cyst and root-knot nematode secreted effector proteins that may function like plant signaling ligands, modulate plant defense response, and even have function similar to malarial parasite effectors were analyzed in detail. These studies have discovered several potential targets to inhibit the parasitic process of root-knot and cyst nematodes to engineer novel resistance in desirable crop cultivars.<br /> <br /> (South Carolina, P. Agudelo) Grain sorghum evaluations. Based on this study, grain sorghum may prove useful in managing Meloidogyne incognita South Carolina populations, but may be susceptible to yield losses due to Columbia lance nematode. <br /> <br /> Patent application for SC04-375RR Soybean Variety. SC04-375RR is a glyphosate-tolerant, high-yielding, maturity group VII soybean variety that has demonstrated excellent seed yields. Plants have white flowers, tawny pubescence, and tan pod walls. Seeds are yellow with variable black hila. SC04-375RR is resistant to Southern root-knot nematode (Meloidogyne incognita), soybean mosaic virus, and stem canker disease, Diaporthe phaseolorum var. caulivora.<br /> <br /> Reniform nematode. A three-year study was conducted in two fields in South Carolina to characterize the horizontal and vertical distribution patterns of RN as influenced by soil texture and crop. Soil samples were collected according to fine scale (field 1) and large scale (field 2) samplings schemes. In the first field (cotton-corn-soybean sequence), soil samples were collected in plots representing different soil textures as inferred by electrical conductivity readings. In the second field (cotton-peanut sequence), samples were collected arbitrarily. Reniform nematode densities showed an aggregated distribution pattern at planting and after harvest in both fields during the three years. However, a significant neighborhood structure was only detected when a host crop was planted. Significant correlations between RN densities and percent sand and silt were detected, showing nematode densities peaked when sand content was around 60 % and declined when sand content increased above 60-65%. Vertically, the highest numbers of RN were found between 15 and 30 cm deep. Understanding the horizontal and vertical distribution patterns of RN is essential for selecting adequate sampling strategies as well as for delineating management zones for site-specific management tactics.<br /> <br /> (Virginia, C. Johnson) Meloidogyne incognita has historically been the most significant root-knot (RK) nematode species on tobacco (Nicotiana tabacum L.) in Virginia. However, most cultivars now contain the Rk1 resistance gene to races 1 and 3 of M. incognita, allowing M. arenaria to become the most common RK species found on tobacco. An increasing number of cultivars also currently possess Rk2 for RK resistance, but aspects of its efficacy are unknown. Four greenhouse experiments were conducted in 2012 - 2013 to investigate whether possessing both Rk1 and Rk2 increases resistance to M. arenaria compared to either gene alone. Each trial was arranged in a RCBD with 6 replications, and compared galling, and numbers of egg masses and eggs from roots of six cultivars C371G (susceptible), NC 95 and SC 72 (homozygous for Rk1), T-15-1-1 (homozygous for Rk2), and STNCB-2-28 and NOD 8 (homozygous for both Rk1 and Rk2). Each plant was inoculated with 5,000 M. arenaria eggs; data were collected 60 days post-inoculation. Plants with Rk1 alone, and Rk1 and Rk2 together, significantly reduced root galling and numbers of egg masses and eggs versus C371G. Compared to presence of Rk1 alone, combining Rk1 and Rk2 further reduced galling in 1 of 4 trials, egg masses in 2 of 4 trials, and eggs in 1 of 3 trials. Because high soil temperatures have been associated with a breakdown in root-knot resistance, the effect of high soil temperature on the efficacy of Rk1 and/or Rk2 genes to M. arenaria are being evaluated at 20, 25, 30 and 35ºC. A better understanding of the effects of Rk1 and Rk2 on root-knot nematode parasitism should help plant breeders improve resistance in tobacco to M. arenaria.<br /> <br /> Objective 2: Identify and incorporate new sources of resistance into elite germplasm lines and cultivars. <br /> (Alabama, K. Lawrence) Over the past decade a concerted effort was made to develop host plant resistance to reniform nematode (Rotylenchulus reniformis) in upland cotton (Gossypium hirsutum). Since 2007 this effort has resulted in the release of several germplasm lines with introgressed resistance to reniform nematode. Currently four groups of released germplasm lines can be distinguished based on their source of resistance and developmental background: (a) the LONREN group, with reniform nematode resistance derived from Gossypium longicalyx, (b) the BARBREN group with reniform nematode resistance derived from wild accession GB-713 of Gossypium barbadense, (c) the M713 group, also with resistance derived from the GB-713 accession but with a different developmental trajectory, and (d) the MT2468 group, with reportedly moderate levels of R. reniformis resistance derived from the photoperiodic primitive race accession TX2468 of G. hirsutum. During 2013 and 2014 we evaluated the potential of 13 lines from these four groups, including three lines of the LONREN group, two lines of the BARBREN group, five lines of the M713 group and three lines of the MT2468 group. Conventional cultivars FM966 and SG747 were included as R. reniformis susceptible controls. Our studies were conducted in the field, on adjacent plots with and without reniform nematode present, on reniform nematode infested outdoor microplots, and in the greenhouse. Results indicate that germplasm lines BAR 41 of the BARBREN group and all five M713 lines combine great R. reniformis resistance with excellent field tolerance. In the 2013 field study, BAR 41 and the group of M713 lines suppressed nematode reproduction by some 90% compared to the susceptible cultivars. At the same time, yield losses due to the nematode were limited to 10% and 5% for BAR 41 and the M713 group, respectively, whereas losses to the cultivars were as high as 65%. <br /> (Arkansas, R. T. Robbins) I am collaborating with Drs. Grover Shannon (Soybean Breeder) and Tri D. Vuong (Soybean Biotechnologist) on developing reniform molecular markers for reniform nematode resistance in soybean. In 2014 we are testing <br /> 138 lines derived from the parent lines Magellan and PI 438489B are being evaluated in greenhouse tests. This is a project funded by the Missouri soybean producers and United Soybean Board. I am also collaborating with Dr. P. Chen (Arkansas) on nematode resistance in his soybean lines and also conducting proprietary contract studies with Monsanto and Phytogen Seed Company looking for reniform resistance in cotton. I am also evaluating biological seed treatments on soybean for FMC.<br /> <br /> (Minnesota, S. Chen) Soybean cyst nematode is most effectively managed by host resistance. However, most commercial SCN-resistant cultivars in the USA are developed from PI88788 and Peking, and frequent use of the limited number of resistance sources has shifted virulence phenotypes of SCN populations (HG Types) to new types that can overcome originally resistant cultivars. A recently identified soybean line PI 567516C is a promising alternative source of SCN-resistance. Genetic studies revealed that the major QTLs conferring SCN-resistance in PI567516C are distinct from the QTLs in PI 88788, Peking, and many other SCN-resistance sources. Two QTLs located on chromosomes 10 (LG O) and 8 (LG A2) in PI 567516C were identified to be resistant to SCN. The QTL on chromosome 10 was the major one with 32.0% additive heritability and 68.7% of the genetic variance of resistance to HG Type 2.5.7, and the closest SNP marker was BARC-008021-00209. The QTL on chromosome 8 displayed 6.8% additive heritability and 14.8% of the genetic variance of resistance to HG Type 2.5.7 and the closest SNP marker was BARC-028207-05794. The two SNP markers can be used to select SCN-resistance from PI 567516C in soybean breeding through marker-assisted selection.<br /> <br /> (Mississippi, G. W. Lawrence and V. Klink) The syncytium that forms during infection affords the unique opportunity to isolate cells undergoing the reaction. Cells undergoing the incompatible reaction have been isolated and analyzed for gene expression occurring exclusively in the incompatible reaction. This identified list of approximately 1,700 genes served as a pool of candidate resistance genes to study using molecular techniques. Highly induced expression of these candidate genes in the susceptible genotype (G. max[Williams 82/PI 518671), in several cases, resulted in identification of genes whose expression suppressed soybean cyst nematode infection. This result demonstrated the efficacy of the approach. Currently, we are testing dozens of candidate resistance genes.<br /> <br /> An analysis of candidate soybean genes involved in the defense occurring between the soybean cyst nematode (SCN) and soybean. In experiments that identified candidate resistance genes that are expressed specifically in the syncytium, supporting experiments resulted in the identification of the involvement of a Syntaxin 31 homolog (Gm-SYP38) functioning in defense. Furthermore, we identified ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) and NONEXPRESSOR OF PR1 (NPR1) that function in salicylic acid (SA) signaling as playing a role in defense. Additional experiments revealed the involvement of BOTRYTIS INDUCED KINASE 1 homolog (Gm-BIK1-6) and the hemicellulose-modifying, xyloglucan endotransglycosylase/hydrolase (XTH) functioning in defense. Currently, we are employing overexpression and RNA interference to better understand the basis of resistance.<br /> The multinucleated syncytium, formed during infection affords the unique opportunity to isolate cells undergoing the reaction. Cells undergoing the incompatible reaction have been isolated and analyzed for gene expression occurring exclusively in the incompatible reaction. Highly induced expression of these candidate genes in the susceptible genotype (G. max[Williams 82/PI 518671), resulted in identification of genes suppressing soybean cyst nematode infection. The induced expression of the Glycine max Syntaxin 31 homolog (Gm-SYP38) and BOTRYTIS INDUCED KINASE 1 homolog (Gm-BIK1-6) rescues G. max[Williams 82/PI 518671] by suppressing SCN infection. RNAi constructs of these genes were engineered into the resistant genotype G. max[Peking/PI 548402] to further test the importance of their role in resistance. The Peking transgenic lines engineered with Gm-SYP38 RNAi constructs significantly increased parasitism, as did the Peking transgenic lines engineered with Gm-BIK1-6 RNAi constructs. <br /> <br /> (Tennessee, T. Hewezi)<br /> In our efforts to search for previously undiscovered nematode effector genes from Meloidogyne incognita, gland-cell-specific mRNA was isolated and sequenced using Roche 454 technology. Using a combination of in silico and molecular approaches we identified 14 novel effector protein candidates. Our data indicates that these effectors play roles at different stages of nematode parasitism, and that the majority likely functions within the cytoplasm of the giant cells.<br /> Among plant-parasitic nematodes only cyst nematodes have been shown to secrete effectors that mimic plant CLAVATA3/ESR-related (CLE) ligand proteins. We have identified multiple tandem CLE-like motifs conserved within the previously identified Meloidogyne avirulence protein (MAP) family that are secreted from root-knot nematodes and have been shown to function in planta. <br /> Recent studies point to key roles of the phytohormone auxin in the regulation of gene expression and establishment of nematode feeding sites. Nevertheless, information about the spatiotemporal expression patterns of the transcription factors that mediate auxin transcriptional responses during syncytium formation is limited. We provided a gene expression map of 22 auxin response factors (ARFs) during the initiation, formation and maintenance stages of the syncytium induced by the cyst nematode. The dynamic distribution and overlapping expression patterns of various ARFs seem to be essential characteristics of ARF activity during syncytium development.<br /> We previously identified Growth regulating factors (GRFs) as key gene regulating plant response to nematode infection. We provided new insight into the molecular mechanisms by which GRFs mediate the overlaps between defense signaling and developmental. WE found that GRFs participate specifically in the regulation of defense-related transcription factors, cell-wall modifications, cytokinin biosynthesis and signaling, and secondary metabolites accumulation. <br /> <br /> Objective 3: Facilitate and improve identification of nematode species and races. <br /> <br /> (Arkansas, R. T. Robbins) My student Churamani Khanal has identified several populations of Root-knot to species used DNA sequences and found an undescribed species of Punctodera. Meloidogyne species identified are M. incognita, M. hapla, M. haplanaria, M. marylandi, M. partityla, and M. arenaria.<br /> <br /> (Louisiana, E. McGawley) Reproduction and pathogenicity of three isolates (from Avoyelles, Evangeline and Rapides parishes, Louisiana) of the reniform nematode, Rotylenchulus reniformis, was compared across three textures (74.4% sand, 20.7% silt and 4.9% clay; 31.4% sand, 55.3% silt and 13.3% clay; and 7.8% sand, 66.3% silt and 25.9% clay) of a commerce silt loam soil on three cultivars (Phytogen 375WF, Stoneville 52788B2F and Stoneville LA887) of cotton. Soil texture with the highest clay content had a significant negative effect on reproduction of all isolates of the nematode on all cultivars of cotton. There was a significant isolate by texture interaction that influenced nematode reproduction only on Phytogen 375WF cotton. Across the three cultivars there were significant differences in reproduction and pathogenicity among the three reniform nematode isolates.<br /> Field studies were conducted to evaluate the influence of the soil nutrients phosphorus and potassium and the nematicide 1,3-dichloripropene on reproduction and pathogenicity of R. reniformis on Phytogen 565 WRF cotton. Over 2 years (2011 and 2012), there were no significant effects of either nutrient on either nematode or plant parameters. There was no significant nutrient X nematicide interaction.<br /> Greenhouse-based inoculation studies with two residential turfgrass types (centipede and St. Augustine) produced reductions in plant dry weights below those of controls for St. Augustine and centipede that averaged 24% and 28% for Meloidogyne incognita and 37.0% and 39.3% for Pratylenchus zeae. <br /> <br /> (South Carolina, P. Agudelo) We studied the genetic variability within H. galeatus and the phylogenetic relationships with closely related species isolated from different crops and locations in the United States. We used morphology, biology, and sequences of the internal transcribed spacer 1 (ITS1) and cytochrome oxidase c subunit I (COI) for comparisons among the Hoplolaimus species isolated. The phylogenetic analysis shows the morphologically distinct H. columbus to be clearly separated from the species morphologically similar to H. galeatus. Within the latter group, H. galeatus, H. magnistylus, H. stephanus, H. concaudajuvencus and two undescribed species form separate clades. A better delimitation of these lance species will allow an improved interpretation of the published data on the distribution and the host/parasite relationships and will help elucidate the ecological and population genetic processes affecting establishment of lance nematodes.<br /> (Virginia, J. Eisenback) A new species on turfgrass is currently being described. This new root-knot nematode has been found in Virginia, Pennsylvania, Marlyand, and Delaware. In the past it has probably been identified as Meloidogyne naasi, but only attacks bentgrass (Agrostis spp.) and no other hosts. Females, males, and second-stage juveniles (J2) were examined by light and scanning electron microscopy. Unique morphological features were discovered that distinguish it from all other described species. The most useful diagnostic character is the length of the tail and tail terminus in the J2 that is 79 and 25 µm, respectively. This species is very common on putting greens on golf courses in Virginia and other states where it causes a slow decline of the grass. <br /> With collaboration of Stephen Thomas, a root-knot nematode parasitic on purple nutsedge (Cyperus rotundus) in New Mexico is being described as a new species. This nematode is very widespread and somewhat damaging to purple nut sedge.<br /> Meloidogyne partityla from laurel oak (Quercus laurifolia) in South Carolina is being compared with M. partityla from pecan in New Mexico. This nematode is extremely variable and has several morphotypes. Since this species was described with mainly drawings and only a few photographs, it is being re-described with additional new characters that may be more useful for its identification. The two populations are somewhat different in the shape of the perineal pattern and in the esterase phenotype. Most populations from pecan have one of three phenotypes: two with two bands and one with four. The esterase phenotype of the population from South Carolina has three bands.<br /> A new species from Turkey Brown fig (Ficus carica) is also being characterized. Although it is generally similar to M. arenaria, this population is distinctly different from all other described species of Meloidogyne. The galls produced on the root system are large (2.5cm in diameter) and contain numerous females, males, second-stage juveniles, and eggs. The perineal pattern and the shape of the male head and stylet are unique and can be used to identify this species. <br />

Publications

Bao, Y., Vuong, T., Meinhardt, C., Tiffin, P., Denny, R., Chen, S., Nguyen, H. T., Orf, J. H., and Young, N. D. 2014c. Potential of association mapping and genomic selection to explore PI88788 derived soybean cyst nematode resistance. The Plant Genome 7 (3): doi10.3835/lantgenome2013.11.0039.<br /> <br /> ?ermák, Václav, Paulo Vieira, Maria ?udejková, Vladimir Gaar, Kate?ina Tománková, Kate?ina Mikušková, Jonathan D. Eisenback, and Manuel Mota. 2014. Detection and characterization of Bursaphelenchus hofmanni Braasch, 1998 associated with peat growing substrate in hop nurseries in the Czech Republic. Nematology 16:739-742.<br /> <br /> Hewezi T, Piya S, Richard G, and. Rice JH (2014). Spatial and temporal expression patterns of auxin response transcription factors in the syncytium induced by the beet cyst nematode Heterodera schachtii in Arabidopsis. Molecular Plant Pathology, 15: 730–736.<br /> <br /> Kularathna, M. T., C. Overstreet, E. C. McGawley, D. M. Xavier, and C. M. Martin. 2014. Influence of soil nutrients on reproduction and pathogenicity of Rotylenchulus reniformis on cotton. Nematropica 44:15-24.<br /> <br /> Lee, H. K., G. W. Lawrence, J. L. DuBien and K. S. Lawrence. 2014. Seasonal variation and cotton-corn rotation in the spatial distribution of Rotylenchulus reniformis in Mississippi cotton soils. Nematropica 44:(In Press).<br /> <br /> Li Y, Lawrence GW, Lu S, Balbalian C, Klink VP (2014) Quantitative Field Testing Heterodera glycines from Metagenomic DNA Samples Isolated Directly from Soil under Agronomic Production. PLoS ONE 9(2): e89887. doi:10.1371/journal.pone.0089887<br /> <br /> Liu J, Nana N, Baum TJ, Hewezi T (2014) Synchronization of developmental processes and defense signaling by growth regulating transcription factors. PLoS ONE 9(5): e98477<br /> <br /> Mallez, Sophie*, Chantal Castagnone, Margarida Espada, Paulo Vieira, Jonathan Eisenback, Manuel Mota, Thomas Guillemaud, Philippe Castagnone-Sereno. 2013. First insights into the genetic diversity of the pinewood nematode in its native area using new polymorphic microsatellite loci. PLOS ONE 8:1-8<br /> <br /> Overstreet, C., E. C. McGawley, A. Khalilian, T. L. Kirkpatrick, W. S. Monfort, W. Henderson, and J. D. Mueller. 2014. Site specific nematode management- development and success in cotton production in the U.S. Journal of Nematology (accepted, in press)<br /> <br /> Pant, Shankar R., Prachi D, Matsye, Brant T. McNeece, Keshav Sharma, Aparna Krishnavajhala, Gary W. Lawrence and Vincent P. Klink. 2014. Syntaxin 31 function in Glycines max resistance to the plant-parasitic nematode Heterodera glycines. Plant Molecular Biology<br /> DOI 10.1007/s11103-014-0172-2<br /> <br /> Plaisance, A. R., E. C. McGawley, and C. Overstreet. 2014. Species abundance and influence of nematodes in urban turfgrass ecosystems in East Baton Rouge Parish, LA. Nematropica 44: (submitted, in review).<br /> <br /> Rutter, W.B., Hewezi, T., Maier, T.R., Mitchum, M.G., Davis, E.L., Hussey, R.S., Baum, T.J. 2014 Members of the Meloidogyne avirulence protein family contain multiple plant ligand-like motifs. Phytopathology 104(8):879-885. <br /> <br /> Ruijuan Li, Aaron M. Rashotte, Narendra K. Singh, David B. Weaver, Kathy S. Lawrence, Robert D. Locy. 2014. Integrated signaling networks in plant responses to sedentary endoparasitic nematodes – a perspective. Plant Cell Report (doi:<br /> 10.1007/s00299-014-1676-6). <br /> <br /> Rutter WB, Hewezi T, Abubucker S, Maier T, Huang G, Mitreva M, Hussey R, Baum T. (2014) Mining novel effector proteins from the esophageal gland cells of Meloidogyne incognita. Molecular Plant-Microbe Interactions, 27: 965-974.<br /> <br /> Rutter WB, Hewezi T, Maier TR, Mitchum MG, Davis EL, Hussey RS, and Baum TJ (2014). Members of the Meloidogyne avirulence protein family contain multiple plant ligand-like motifs. Phytopathology, 104:879-885.<br /> <br /> Schrimsher, Drew W., Kathy S. Lawrence, Roelof B. Sikkens, and David B. Weaver. 2014. <br /> Nematicide enhancement of Rotylenchulus reniformis resistant cotton genotypes. Journal of Nematology 46:(In Press).<br /> <br /> Shaohui Wu*, Roger R. Youngman, Loke T. Kok, Jonathan D. Eisenback, Curt A. Laub, Sally L. Paulson. 2014. Interaction between Heterorhabditis bacteriophora and Metarhizium anisopliae: Role of infective juvenile nematode in the vertical distribution of fungal conidia in soil. Journal of Entomological Science 41:233-239.<br /> <br /> Xavier, D. M., C. Overstreet, E. C. McGawley, M. T. Kularathna, and C. M. Martin. 2013. The influence of soil texture on reproduction and pathogenicity of Rotylenchulus reniformis on cotton. Nematropica 44:7-14.<br /> <br /> Proceedings<br /> <br /> Bailey, D. L., K. S. Lawrence, and D. W. Held. 2014. Soybean variety soil type and irrigation effects on reniform nematode populations. Proceedings of the 2014 Beltwide Cotton ConferenceVol. 1: 270-275. National Cotton Council of America, Memphis, TN. http://www.cotton.org/beltwide/proceedings<br /> <br /> Davis, E.L., and D.K. Nendick. 2014. Phytoparasitic nematodes: risks and regulations. Pp 519-546 In McKirdy, S., and G. Gordh, eds. Plant Biosecurity Handbook. Springer Science & Business Media, B.V. London, UK.<br /> Faske, T. R., 2014. Sensitivity of Meloidogyne incognita to fluopyram. Proceedings of the Beltwide Cotton Conferences; January 7-9; New Orleans, LA. National Cotton Council, Memphis, TN. Pp 294.<br /> <br /> Faske, T. R., and Hurd, K. 2014. Sensitivity of Meloidogyne incognita and Rotylenchulus reniformis to fluopyram. Proceedings of the Southern Soybean Disease Workers Annual Meeting; March 5-6; Pensacola, FL<br /> <br /> Land, C. J., K. S. Lawrence, B. Meyer, C. H. Burmester. Verticillium Wilt on-farm cotton cultivar variety evaluations. 2014. Proceedings of the Beltwide Cotton Conference, Vol. 1: 266-269. National Cotton Council of America, Memphis, TN. http://www.cotton.org/beltwide/proceedings/2005-2012/index.html<br /> <br /> Lawrence, K. S., C. D. Monks, and D. Delaney. Eds. 2013 AU Crops: Cotton Research Report. March 2014. Alabama Agricultural Experiment Station Research Report Series No. 43. file:///F:/2011%20Passport/AU%20Crops%20report/AU%20Crops%20cotton%20%20report%202014/Cotton%20Bulletin%202014.pdf<br /> <br /> Lawrence, K., G. Lawrence, T. Faske, C. Overstreet, T. Wheeler, H. Young, S. Koenning, J. Muller, R. Kemerait, H. Mehl. 2014. Cotton variety and nematicide combinations for reniform and root-knot management across the cotton belt. Proceedings of the 2014 Beltwide Cotton ConferenceVol. 1: 295-301. National Cotton Council of America, Memphis, TN. http://www.cotton.org/beltwide/proceedings<br /> <br /> Lawrence, K., M. Olsen, T. Faske, R. Hutmacher, J. Muller, J. Mario, R. Kemerait, C. Overstreet, G. Sciumbato, G. Lawrence, S. Atwell, S. Thomas, S. Koenning, R. Boman, H. Young, J. Woodward, and H. Mehl. 2014. Cotton disease loss estimate committee report, 2013. Proceedings of the 2014 Beltwide Cotton Conference Vol. 1: 247-248. National Cotton Council of America, Memphis, TN. http://www.cotton.org/beltwide/proceedings<br /> <br /> Robbins, R. T., G. Shannon, P. Chen, S. K. Kantartzi, L. E. Jackson, E. E. Gbur, D. G. Dombek, J. T. Velie, and T. R. Faske. 2014. Reniform Nematode Reproduction on Soybean Cultivars and Breeding Lines in 2013. Proceeding of the 2014 Beltwide Cotton Conferences, New Orleans Jan 6-8. Pgs. 226-236<br /> <br /> Rothrock C. S., S. A. Winters, J.D. Barham, A. B. Beach, M. B. Bayles, P. D. Colyer, T. Kelley, R. C. Kemerait, G.W. Lawrence, K. S. Lawrence, G.B. Padgett, P. M. Phipps, G. L. Sciumbato, R. Thacker, and J. E. Woodward. 2014. Report of the Cottonseed Treatment Committee for 2013. Proceedings of the Beltwide Cotton Conference, Vol. 1:249-255. National Cotton Council of America, Memphis, Tennessee. http://www.cotton.org/beltwide/proceedings/2005-2013/index.html<br /> <br /> Sikkens, R.B., D.B. Weaver, K.S. Lawrence and R.L. Nichols. 2014. Comparative Performance of Reniform Nematode Resistant Germplasm Lines. Proceedings of the 2014 Beltwide Cotton Conferences Vol. 1:652-659. National Cotton Council of America, Memphis, Tennessee. http://www.cotton.org/beltwide/proceedings/2005-2013/index.html<br /> <br /> Smith, A. L., K. S. Lawrence, K. Glass, and E. van Santen. 2014. Cotton Cultivar Evaluations for Resistance to Fusarium Wilt and Root-knot Nematode Disease Complex in Alabama. Proceedings of the 2014 Beltwide Cotton Conference Vol. 1: 261-265. National Cotton Council of America, Memphis, TN. http://www.cotton.org/beltwide/proceedings<br /> <br /> Xiang, N., K. S. Lawrence, J. W. Kloepper, and J. A. McInroy. In vitro screening of biological control agents on Meloidogyne incognita. 2014. Proceedings of the 2014 Beltwide Cotton ConferenceVol. 1: 258-260. National Cotton Council of America, Memphis, TN. http://www.cotton.org/beltwide/proceedings<br /> <br /> Abstracts<br /> <br /> Bao, Y., Chen, S., Denny, R., Kurle, J. E., Meinhardt, C., Nyuyen, H. T., Orf, J. H., Tiffin, P., Vuong, T., and Young, N. D. 2014a. Implementing association mapping and genomic selection in soybean breeding programs. 15th Biennial Conference Molecular & Cellular Biology of the Soybean: 22. (Abstr.).<br /> <br /> Bao, Y., T. Vuong, C. Meinbardt, R. Denny, H. T. Nguyen, S. Chen, P. L. Tiffin, J. Orf, and N. D. Young .2014b. Association mapping and genomic selection for soybean cyst nematode resistance. PLant and Animal Genome, The Largest Ag-Genomics Meeting in the World. Web/URL: https://pag.confex.com/pag/xxii/webprogram/Paper12449.html. (Abstr.).<br /> <br /> Churamani Khanal and R. T. Robbins, 2014 Meloidogyne partityla, a new Root-Knot species to Arkansas. Southern American Phytopathological Society meeting, Dallas<br /> <br /> Churamani Khanal, Weimin Ye and R. T. Robbins 2014. A new record of Meloidogyne partityla and an unknown species of Punctodera from Arkansas. American Phytopathological Society annual meeting, Minneapolis<br /> <br /> Davis, E.L. 2014. Functional analyses of root-knot and cyst nematode effectors. Proceedings of the 6th International Congress of Nematology, Cape Town, South Africa.<br /> <br /> Donald, P., K. Lawrence, T. Kirkpatrick, B. Kemerait, J. Bond, D. Herschman, C. Overstreet,<br /> A. Wrather, G. Lawrence, S. Koenning, P. Agudelo and C. Canaday. 2014. Occurrence, distribution, and impact of nematodes in soybean fields in the southern United States. Journal of Nematology Vol. 46:154-155.<br /> <br /> Duong, L.T., K.S. Lawrence, J.F. Murphy and R.B. Sikkens. 2014. Interaction of Bean Pod Mottle Virus, Soybean Mosaic Virus and Reniform Nematode on Yields of Soybean (In press). The American Phytopathological Society, St. Paul, MN.<br /> <br /> Eisenback, J.D. and Paula Agudelo. Comparisons of nematode assay labs efficiencies and recommendations from ten nematode assay labs utilizing samples from turfgrass. Paper presented at the 6th International Congress of Nematology, Cape Town, South Africa, May 2014.<br /> <br /> Faske, T. R. and Hurd, K. 2014 Sensitivity of Meloidogyne incognita and Rotylenchulus reniformis to fluopyram. Phytopathology 104:S2.4.<br /> <br /> Holguin, C. M., Agudelo, P., Gerard, P., Mueller, J. and Khalilian, A. Spatio-Temporal distribution of reniform nematode (Rotylenchulus reniformis) and relationships with soil texture. Poster presented at the 6th International Congress of Nematology, Cape Town, South Africa, May 2014.<br /> <br /> Holguin, C. M. Agudelo, P., Baeza, J.A., Mueller, J.D. A phylogenetic approach for the identification of Hoplolaimus galeatus and closely related species. Paper presented at the 6th International Congress of Nematology, Cape Town, South Africa, May 2014.<br /> <br /> Holguin, C. M., Agudelo, P., Gerard, P., Mueller, J. and Khalilian, A. Spatial distribution of renifom nematode (Rotylenchulus reniformis) in cotton fields. Paper presented at the XLV Annual ONTA meeting, La Serena, Chile, October 2013.<br /> <br /> Juvale, P.S., Maier, T.R., Walter, C., Hewezi, T., Davis, E.L., Mitchum, M.G., <br /> Baum, T.J. 2014. Cyst nematode effectors modulating plant defense mechanisms for successful parasitism. Proceedings of the International Congress for Molecular Plant-Microbe Interactions, Rhodes, Greece.<br /> <br /> Land, Caroline, K. S. Lawrence. 2014. Greenhouse Evaluation of Inoculation Methods and Commercial Cotton Cultivars in the Presence of Verticillium Wilt. (In Press) The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence, K.S., C. Land and R. Sikkens. 2014. A new in-furrow nematicide for Rotylenchulus reniformis and Meloidogyne incognita nematode management in cotton. Journal of Nematology Vol. 46:191-192.<br /> <br /> Li, W., P. Agudelo, and C. Wells. Interactions between cotton and reniform nematode. Poster presented at the 6th International Congress of Nematology, Cape Town, South Africa, May 2014.<br /> <br /> Lian, L., Wang, F., Denny, R., Schaus, P., Young, N., Orf, J., and Chen, S. 2014. Soybean cyst nematode resistance in PI 567516C soybean: a promising new source of resistance. Journal of Nematology 46:193. (Abstr.).<br /> <br /> Luangkhot, J., K.S. Lawrence, and J. Spiers. 2014. Actinidia sp. susceptibility to Phytophthora. 2014 APS-CPS Joint Meeting. (In Press) The American Phytopathological Society, St. Paul, MN.<br /> <br /> Noon, J.B., T. Hewezi, U. Muppirala, T.R. Maier, D. Dobbs, C. Simmons, J.Z. Wei, G. Wu, E.L. Davis, M.G. Mitchum, R.S. Hussey, T.J. Baum. 2014. Malaria parasite effectors in a single genus of plant-parasitic nematodes. Proceedings of the ICMPMI, Rhodes, Greece.<br /> <br /> Pant, S.R., P.D. Matsye, B.T. McNeece, K. Sharma, A. Krishnavajhala, G.W. Lawrence, V.P. Klink. 2014. Syntaxin 31 function in Glycines max resistance to the plant-parasitic nematode Heterodera glycines. Journal of Nematology Vol. 46: 216.<br /> <br /> Pollok, J., C. Johnson, J. Eisenback, D. Reed. 2014. Reproduction of Meloidogyne arenaria on flue-cured tobacco homozygous for Rk1 and/or Rk2. (In Press) The American Phytopathological Society, St. Paul, MN.<br /> <br /> Redding, N., P. Agudelo, and C. Wells. Host-plant gene expression during infection of syncytium-forming nematode Rotylenchulus reniformis. Oral presentation at the 6th International Congress of Nematology, Cape Town, South Africa (May 2014)<br /> <br /> Ruark, C. L. Sit, T.L. Koenning, S. R., and Lommel, S.A. Analysis of viral sequences within soybean cyst nematodes. Proceedings of the 6th International Congress of Nematology. 4-9 May 2014. Cape Town South Africa.<br /> <br /> Sikkens, R.B., K.S. Lawrence, D.W. Schrimsher, S.R. Moore and D.B. Weaver. 2014.<br /> Upland cotton germplasm lines with introgressed resistance to the reniform nematode. Journal of Nematology Vol. 46:235-236.<br /> <br /> Sikkens, R.B. and K.S. Lawrence. 2014. Nematode Resistance Screening of Upland Cotton using Microplots (In press). The American Phytopathological Society, St. Paul, MN.<br /> <br /> Smith, A. L., K. S. Lawrence, K. Glass, and J. Hu. 2014. Identification of Fusarium oxysporum f. sp. vasinfectum races present in Alabama cotton fields. (In Press) The American Phytopathological Society, St. Paul, MN.<br /> <br /> Xiang, N., K. S. Lawrence, J. W. Kloepper, and J. A. McInroy. 2014. Biological control and plant growth promotion of Bacillus spp. on Meloidogyne incognita in cotton. 2014. (In Press) The American Phytopathological Society, St. Paul, MN.<br /> <br /> Xiang, N., K.S. Lawrence, and C. Norris. 2014. Soybean nematicide combinations for reniform nematode management in north Alabama, 2013. Report 8: N009. DOI: 10.1094/PDMR08. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Plant Disease Management Reports<br /> <br /> Bailey D. L., K.S. Lawrence, R. B. Sikkens, C. J. Land and C. Norris. 2014. Evaluations for Cotton Disease with the Use of Fungicide Management in North Alabama, 2013. Report 8:ST019 DOI:11.1094/PDMR08. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Bailey D. L., K.S. Lawrence, C. J. Land, R. B. Sikkens, C.H. Burmester and C. Norris. 2014. Cotton Variety and Fungicide Combinations for Seedling Disease Management in North Alabama, 2013. Report 8:ST018 DOI:11.1094/PDMR08. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Emerson, M., Faske, T. R., and Hurd, K. 2014. Evaluation of nematicides for control of root-knot nematode in corn in Arkansas, 2013.PDMR 8: N013<br /> <br /> Land, C.J., K. S. Lawrence, C. H. Burmester, and C. Norris. 2014. Experimental Nematicides for management of the reniform nematode in North Alabama, 2013. Report 8:ST014 DOI:11.1094/PDMR08. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Land, C.J., K. S. Lawrence, C. H. Burmester, and C. Norris. 2014. Evaluation of experimental nematicides for the management of the reniform nematode in north Alabama, 2013. Report 8:ST015 DOI:11.1094/PDMR08. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Land, C.J., K. S. Lawrence, C. H. Burmester, and C. Norris. 2014. Experimental biological management of the reniform nematode in north Alabama, 2013. Report 8: ST016 <br /> DOI:11.1094/PDMR08. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Land, C.J., K. S. Lawrence, S. Nightengale. 2014. Efficacy of experimental biological management of the root knot nematode in Alabama, 2013 Report 8:ST017 DOI:11.1094/PDMR08. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence K. S., R. B. Sikkens, C. J. Land and C. Norris. 2014. Fungicide Combination Evaluations for Cotton Seedling Disease Management in North Alabama, 2013. Report 8:ST0002 DOI:11.1094/PDMR08. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence K. S., C. J. Land, R. B. Sikkens, C.H. Burmester and C. Norris. 2014. Cotton Variety and Nematicide Combinations for Reniform Management in North Alabama, 2014. Report 8:ST001 DOI:11.1094/PDMR08. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Lawrence K. S., C. J. Land, R. B. Sikkens, C.H. Burmester and C. Norris. 2014. Cotton Variety and Nematicide Combinations for Reniform Management in North Alabama, 2014. Report 8:N001 DOI:11.1094/PDMR08. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Smith, A. L., K. S. Lawrence, and S. Nightengale. 2014. Cotton seed treatment combinations for Fusarium wilt and root-knot nematode management in Alabama, 2013. Report 8: ST003 DOI:11.1094/PDMR07. The American Phytopathological Society, St. Paul, MN.<br /> <br /> Xiang, N., K.S. Lawrence, D. Schrimsher, and S. Nightengale. 2014. Evaluation of Temik, Aeris, and two experimental compounds on cotton for root knot management in Alabama, 2013. Report 7:N006. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> Xiang, N., K.S. Lawrence, D. Schrimsher, and S. Nightengale. 2014. Evaluation of Poncho Votivo, Aeris, Temik, and UFS0 738 on cotton for root knot management in Alabama, 2013. Report 7:N005. DOI: 10.1094/PDMR07. The American Phytopathological Society, St. Paul, MN. <br /> <br /> Web sites<br /> <br /> McGawley, E.C. and C. Overstreet. 2014. Poster Illustration: Common Genera of Plant Parasitic Nematodes. Posted to websites of Society of Nematologists, Organization of Nematologists of Tropical Americas, European Society of Nematologists and Russian Society of Nematologists.<br /> <br /> Mueller, J.D. and P. Agudelo. 2014. Cotton Nematode Management in the South. Focus on Cotton Webcasts, January 2014.<br /> <br /> Patent application for SC04-375RR Soybean Variety<br />

Impact Statements

1. 1. Molecular techniques are identifying genes used in parasitic reaction by the Soybean Cyst Nematode. These will be useful in developing soybean varieties with resistance to this serious nematode pest.
2. 2. Continued field experimentation with new and existing nematicides is a necessity to provide our agricultural producers with a short term management tools for nematode pests.
3. 3. Rotation is the most economically feasible method of reniform control until acceptable commercial cotton varieties are available. In cotton when uncontrolled the reniform nematode can reduce yield to the point where cotton production is not profitable. A good rotation, such as corn-cotton, sorghum-cotton or reniform resistant soybean-cotton can restore profitability to these infested fields.
4. 4. RKN and RN are major pathogen of soybean and cotton in Arkansas. Currently, there are few management options in soybean and resistance is lacking thus, many producers are partnering available resistance with nematicides. Fluopyram is expected to be available in 2015 as ILeVO thus; these activities will be beneficial to the row crop producers as they manage these plant diseases.
5. 5. Agricultural productivity now and in the future requires the development of improved and cost effective methods for identifying nematodes and formulating management tactics compatible with changing cropping practices, production system technology and environmental concerns.
6. 6. Description of a new species of root-knot nematode on turfgrass is the first step in eliminating the harmful effects that this pest plays on the health and vigor of bentgrass on vitally important greens on golf courses in the mid-atlantic states including Virginia, Maryland, Pennsylvania and Delaware.
7. 7. The identification of a new root-knot species parasitizing purple nutsedge may be helpful in developing a natural biocontrol of this difficult to control weed species.
8. 8. Finding and describing a new species of root-knot nematode on fig may help find new control methods of root-knot on fig by screening fig cultivars for resistance to this economically important plant pathogen.
9. 9. Characterizing the morphological and physiologically diverse populations of Meloidogyne partityla may make the identification of this economically important root-knot nematode species easier and more certain which is a first step in minimizing the financial loses imposed by this pest.
10. 10. The Fusarium wilt Root knot nematode disease complex effect on cotton yield can be reduced by variety selection.
11. 11. The cotton germplasm lines BAR 41 and all five M713 lines combine great R. reniformis resistance with excellent field tolerance and may contribute to a reniform resistant cultivar in cotton.
12. 12. Grain sorghum varieties useful for management of Meloidogyne incognita have been identified.
13. 13. Soybean varieties with resistance to Meloidogyne incognita were developed.
14. 14. Several factors determining reniform nematode distribution in the field were identified
15. 15. Genetic variability of Hoplolaimus stephanus populations in the United States was measured.
16. 16. This study will provide useful information for strategically deploying appropriate sources of SCN-resistance for managing SCN.
17. 17. Identifying novel nematode effector proteins and host factors that are responsible for infection and disease will facilitate our understanding of the molecular mechanisms underlying nematode parasitism of host plants. This ultimately will provide situations for interference with nematode development in order to render host plants resistant to parasitic nematodes.
18. 18. Information about the latest methods for control of various nematode species in North Carolina have been disseminated through county extension meetings and the 2013 North Carolina Crop Protection School.

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