Brief Summary of Minutes of Annual Meeting

Collaborative Activities in 2002: NCR-137 member states were involved in many collaborative activities during 2002. The most prominent were the multi-state research activities focusing on important disease problems common to most states which included:
NC Soybean Research Program research projects for White Mold of Soybean
NC Soybean Research Program research projects for Phytophthora root and stem rots.
NC Soybean Research Program research projects for Sudden Death Syndrome.
Establishment of an interest group for Brown Stem Rot.
The NCSRP research projects consist of coordinated cooperative projects. Each project holds an annual meeting to present research results; develop, organize and coordinate future research, and handle administrative functions.
Additional collaborations have been developed with researchers in:
NCR-504 - Soybean rust.
NCR-200 - Virus diseases of soybean.
The annual meeting of NCR-137 was held in conjunction with NCR-504 mini-symposium. Topics presented:
Research on host resistance to soybean rust.
Research on fungicide efficacy and status of fungicide clearances.
Epidemiology of soybean rust as an invasive species in the US.
The meeting also coincided with the annual Soybean Breeders workshops held the two days following at the Sheraton Chateau in St. Louis.

Transferring information and technology: NCR-137 members have devoted much effort to outreach activities accessible to researchers, producer, extension, the agribusiness community, and to the public. An example is the Plant Health Initiative website maintained and supported by the NCR Soybean Research Program at http://www.planthealth.info/. All states in NCR-137 established websites accessible directly or through links with Plant Health Initiative website The Univ of Wisconsin Soybean Plant Health web site, located at http://www.plantpath.wisc.edu/soyhealth is one example.

Plans for coming year:
Request renewal of NCR-137 takes place in 2003.
Establish a clearing house to collect, organize and report results of seed treatment trials from throughout the nine states of the NCR. Results will be presented on the Plant Health Initiative website.
Establish a website for NCR-137.


NCR-137 members, by state, reported the following activities during 02-03:

Illinois: The National Soybean Pathogen Collection Center was established at the Univ of Illinois for Phytophthora, SDS, SCN, and root knot nematode. Major research projects on SDS, SCN, Phytophthora root rot, and white mold are continuing. A major focus on soybean rust has also started, including screening for resistance at Fredrick, MD (USDA cooperative project)& fungicide evaluation using Septoria blight as a model system.

Indiana: Major research activities & screening for resistance involve Phytophthora root rot, SDS, soybean cyst nematode, & Sclerotinia stem rot. Research on population dynamics of P. sojae in soybean fields continues to identify races, 1,3,4,7,13,25,28,33,43 and 44 as the pre-dominant races in Indiana. The addition of Dr. Andres Westphal has increased the research activity on SDS and SCN in Indiana. In addition, Dr. Westphal is actively involved in biological control of soybean pathogens.

Iowa:
Charlotte Bronson: New chairwoman of department. Interaction between SCN and BSR, BSR resistance marker.
Tom Harrington: Brown stem rot pathogen classification. Propose two races for this pathogen.
John Hill: Seed transmission of bean pod mottle virus.Transmission of soybean mosaic virus by Asian aphid. He has confirmed the transmission by this new vector. Resistance of transgenic plants to soybean mosaic virus.
Gary Munkvold: Management of soybean brown stem rot with precision farming tools. Herbicide interaction with brown stem rot and SDS
Forrest Nutter:Epidemiology of soybean mosaic virus in transgenic plants. Neural network modeling soybean cyst nematode (with Tylka). Soybean rust remote sensing
Greg Tylka: Soybean cyst nematode management, SCN education program, BSR and SCN interaction (with Bronson)
X.B. Yang: Disease resistance evaluation, Phytophthora, SDS. WM  NCSRP Phytophthora race survey. Regional disease prediction - white mold as a model system. SDS Fsg germplasm conservation  USDA. SDS pathogenicity and inoculation method development. Soybean rust risk management - Hartman and USDA-FDWRSU

Minnesota: Using the petiole inoculation technique more than 1200 breeding lines were evaluated for resistance to Sclerotinia stem rot. A resistant MG 00 line was identified is being made available through the soybean breeding project. The relationship of soilborne pathogens to iron chlorosis symptom expression & the interaction of SCN, Phytophthora root rot, and iron chlorosis was evaluated. Management studies evaluating the effect of plant population on iron chlorosis found that higher planting rates resulted in reduced chlorosis but not in increased yields. Soybean production in Minnesota has expanded into areas with a limited history of soybean production. Inoculation with Bradyrhizobium strains selected for adaptation to soil & environmental conditions in these areas is proving to be a very cost effective strategy for increasing yield & reducing root rot severity.

Missouri: Eleven Univ of Missouri scientists are currently conducting experiments on the biology and management of various soybean diseases. Soybean germplasm line S96-2692, mid-maturity group 5, was released. It has resistance to races 1, 2, 3, 4, and 14 of SCN, resistance to southern root-knot nematodes, and reniform nematodes. Soybean germplasm line S97-1688, mid-maturity group 5, was released. It has resistance to races 1, 2, 3, 4, and 14 of SCN, and seeds have high protein content. Roundup effected the interactions between SCN, roundup ready soybean and rhizosphere fungi. Field studies revealed Roundup applied alone or combined with selected Fusarium to soil at planting reduced SCN cysts on soybean roots up to 70%. A survey of soybean plants with symptoms of virus infection was conducted in Missouri during late-summer. BPMV was found in all of the samples, all were negative for SMV. All samples with symptoms of green stem syndrome tested positive for BPMV and TRV. Estimates of soybean yield suppression due to diseases in each state in the USA and Ontario for 99-02 will be published in Plant Health Progress during 2003.

Nebraska: The main focus of soybean virus pathology is Bean pod mottle virus. Effects of planting date on BPMV incidence and disease management through early season vector control is ongoing. This research is part of the NCSRP virus project. During 2002, we tested (detached leaf) the Sclerotinia stem rot reaction to 98 lines developed by the UNL soybean-breeding program for excellent agronomic characteristics. Preliminary results indicate that some of the high-yield lines also have smaller disease lesions (= greater resistance) comparable to NKS 19-90. We collaborated with Univ of Illinois scientists in testing six select Sclerotinia sclerotiorum isolates on three lines each of soybean and common bean with different levels of resistance using three methods of screening for disease reaction. Detached leaf test and cut stem test were rated the best on soybean and only two tests were correlated on common bean. Sclerotinia sclerotiorum isolates were ranked as high, medium and low virulence. This will allow isolates to be selected for specific tests. Field trials in 02 were designed to test the ability of Perkla (Ca-cyanamide) to inhibit apothecial formation of Sclerotinia sclerotiorum & reduce disease in transgenic soybean lines that resist the herbicide effects of Perkla.

Ohio: We have mapped the new Rps gene (Rps8) to Phytophthora sojae in the USDA Soybean germplasm collection of PI399073 from South Korea to molecular linkage group A2. The OSU soybean breeding program has licensed germplasm that contains this gene and they are in the process of developing both soybean varieties and germplasm with this gene in combination with Rps3a and/or Rps1k. Plans are to continue to identify markers more closely associated with this locus as well as continue to identify Rps alleles in the remaining 31 PIs in this collection. We have identified two putative QTLs linked to partial resistance to P. sojae in the soybean cultivar Conrad. One QTL on MLG F explained 32.4, 35.0, and 21.4 percent of the genotypic variation for Conrad x Sloan, Conrad x Harosoy, and Conrad x Williams populations, respectively. The second QTL is located on MLG D1b+W explained 10.6, 15.9, and 20.7 percent of the genotypic variation for the same three populations. In collaboration with Dr. Scott Abney, USDA-ARS- Isolates of P. sojae representing races 1, 3, 4, 7 and 25 from IN & OH were compared on three separate sets of soybean differentials using three separate seed sources. Races 1, 3, 4, 7, and 25 had the expected reaction on all three sets of differentials for Rps1b, Rps1c, Rps1k, Rps2, Rps3a, Rps4, Rps5, Rps7 & differentials Harlon, L59-731, & Union for Rps1a. Differentials L88-8470 for Rps1a and L93-3302 for Rps1d did not have the expected response.

Ontario: Research focused on Phytophthora root rot, Sclerotinia stem rot, & soybean cyst nematode & involve the identification of new sources of resistance, molecular markers, QTLs for tolerance, screening methods, & management strategies.

Pennsylvania: We established a factorial experiment to examine the effects of row spacing, planting density and weed canopy on the development of Sclerotinia stem rot during 2002. Despite infestation of soil with sclerotia and nightly mist irrigation sufficient levels apothecia did not develop and disease was absent in the plots. Low rate of carpogenic germination of the sclerotia was attributed to high soil temperatures. More specifically, average soil temperature measured at a depth of 2 in. within the plots was 25.3 C, temperatures greater than 29.5 C were recorded for 120.5 hours. Soil temperatures greater than 30 C have been reported to reduce apothecia production by Sclerotinia.

Wisconsin: Severity of brown stem rot & population density of Phialophora gregata in host tissue was inversely correlated with soil pH. Yield advantage of brown stem rot resistant varieties was greatest at pH 6.0 & was lost at soil pH 7.4 & above.
Soybean varieties with partial resistance to brown stem rot are vulnerable to yield loss associated with this disease. Research efforts were intensified in 2002 to search for higher forms of resistance to brown stem rot. Traditionally resistance to brown stem rot has been characterized by leaf & stem symptoms. Symptom severity and pathogen reproduction were both employed to characterize interaction phenotypes of soybean lines in field trials in 2002. A collaborative study with Brian Diers, Univ of Illinois, to determine the relationship between sources of SCN-resistance and reaction to genotypes of P. gregata was continued. Other research has focused on understanding the effect of the soybean aphid, bean leaf beetle and associated viruses; soybean mosaic, alfalfa mosaic, bean pod mottle, and tobacco streak viruse on the health and productivity of soybeans; in order to formulate management strategies to reduce yield losses associated with this insect-virus complex. Management practices being investigated include evaluation of germplasm for host plant resistance, insecticide application, & the effects of foliar applied herbicides. The petiole inoculation technique was used to characterize 30 different sources of germplasm for partial resistance to S. sclerotiorum. The cultivars Maple Arrow and MN1401 and breeding lines M90-184111 and M91-196123 expressed partial resistance to S. sclerotiorum. Plant introductions that expressed partial resistance higher than S19-90 were 153.235, 184.042, 507.792, 561.285B, 561.345, 561.367, 567.157A and 567.157B.