Brief Summary of Minutes of Annual Meeting

The project activities are covered in four objectives. Project activities involve research utilizing molecular tools and the application of the laboratory and greenhouse research into nematode control in the field. We have organized this year's accomplishments under the four project objectives. OBJECTIVE 1: Characterization of Nematode Genetic and Biological Variation Relevant to Crop Production and Trade Plant-parasitic nematodes have complex relationships with their host plants and these interactions can be confusing. The project has focused on three groups of nematodes the past year - Rotylenchulus reniformis, the reniform nematode, Meloidogyne, the root-knot nematodes, and Globodera, the round cyst nematodes. Reniform nematode limits yield of many important crops. In upland cotton, resistance was identified and incorporated into germplasm and releases as LONREN. The unique relationship between the nematode and the host plant has been demonstrated in LONREN. Whereas LONREN prohibits reniform nematode reproduction, at moderate nematode population levels plant reaction to the nematode is so severe as to cause yield reduction. In cowpea where root-knot nematode resistance is well defined, reniform nematode reproduction was variable. Several cowpea varieties with resistance to root-knot nematode appear to have resistance to reniform nematode as well. Reniform nematode resistance in soybean remains difficult to find, with most commercial and breeding lines being susceptible. Root-knot nematode resistance in grains, carrots, and cotton is often limited to a few genes and we need to direct efforts to expanding the base of resistance deployed in the field. Meloidogyne incognita reproduction on red-skinned potato cultivars differs and shows behavior similar to renifrom nematode on cotton. Some red-skinned potatoes are tolerant resistant whereas others are tolerant susceptible. It can be difficult to find Meloidogyne incognita, a root-knot nematode, resistance in corn hybrids. Of 40 hybrids examined, none are resistant. Meloidogyne hapla, a root-knot nematode, and the damage it causes to vegetable crops has been demonstrated to have a significant location-specific component. The pecan root knot nematode, Meloidogyne partityla, is challenging to control because of. Whereas the nematode host range is limited, the perennial nature of the pecan host renders most rotation options moot. The discovery of Globodera palida in Idaho several years ago prompted surveys across the region to identify other areas of infestation. While no other infestations were found, a new species of Globodera was identified. This species, not of regulatory concern, has only been identified in a limited geographic area. This new species has strong diapause and appears to be responsive to stimulation from solanaceous plants. Its biology has limited our progress in delimiting its host range and documenting its damage potential. OBJECTIVE 2: Determination of Nematode Adaptation Processes to Hosts, Agro-Ecosystems and Environments Information on nematode identification and phylogenetics (concentrating on the Criconematid) is especially important was we experience climate change and possible changes in cropping systems. A 635 bp 3' region of 18S rDNA has been used to bar code nematodes. With nematodes, the differentiation of species and their classification is at times extremely important (for resistance and rotation based control) and at other times less important (with the use of nematicides). As plant-nematologists, we struggle with what is needed to separate species-morphological differences, molecular differences, host range, or its pathogenicity. A Meloidogyne species isolated from guava in Thailand was found to have variable perineal patterns, a VS1-S1 esterase phenotype, and a COII primer fragment of 700 bp. These characteristics show the species to be Meloidogyne enterolobii, a first report of the species in Thailand. The utility of molecular diagnostic tests continues to expand. A test has been developed for reniform nematode in soil using a quantitative PCR (qPCR)-based assay. The qPCR procedure accurately detects the reniform nematode as well as estimating the number of nematodes from metagenomic DNA isolated from the same soil sample. OBJECTIVE 3: Development and Assessment of Nematode Management Strategies in Agricultural Production Systems Crop rotation remains tried and true approach for nematode control in many cropping systems. Generally rotations that cycle over several years are more effective than our common 1-year rotations. Rotations that strive to control mixed nematode mixed populations, such as root-knot and reniform in cotton, are especially challenging. Effective rotations employ alternate and non-hosts in addition to resistance genes. Planting the same crop in consecutive years, consistently results in lower yields in most all cropping systems. Precision agriculture can be used to effect nematode control. Research as demonstrated that nematicide rates can be targeted to nematode population densities with a subsequent reduction in total pesticide used. However, the challenge remains in the economic assessment nematode population densities in the soil. Water availability throughout the growing season should be considered in risk assessment when creating site-specific management for nematodes, especially the reniform nematode. Research into biological control alternatives for nematodes continues on several fronts. Bacillus firmus strain GB-126 (Votivo® by Bayer) reduces the number of vermiform life stages of reniform nematodes in the soil, and the number of females infecting roots. Consequently, lower number of eggs per gram of root are produced. While not sufficient to protect the crop from damage, the reduction in nematode population may have utility in shortening rotations and allowing resistance to be more effective. OBJECTIVE 4: Implementation of Rapid Information Transfer of Project Results to Stakeholder The project employs a variety of venues to convey information to our varied stakeholders. Current nematicide and variety tests are published university web sites. Information is also delivered at annual meetings of professions as exemplified by Cotton Belt meeting, society meetings like the Society of Nematologists, and grower meetings. Information is published in scientific and lay journals. 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. The inclusion of a web service to this project increases the impact of this project.

Book Chapters 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. 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. 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. Plant Tissue Culture and Applied Plant Biotechnology Chapter 10: pages 249-270. Journal Articles R.Y.M. Cabos, B.S. Sipes, C. Nagai, M. Serracin and D.P. Schmitt. 2010. Evaluation of coffee genotypes for root-knot nematode resistance. Nematropica 40:191-202. Doshi, R. A., R.L. King and G.W. Lawrence. 2010. Classification of Rotylenchulus reniformis numbers in cotton using remotely sensed hyperspectral data on self-organized maps. Journal of Nematology:42 179-193 Skantar, A.M., Handoo, Z.A., Carta, L.K., Zasada, I. A., Ingham, R.E., Chitwood, D.J. 2011. Morphological and molecular characterization of Globodera populations from Oregon and Idaho. Phytopathology. 101:(4)480-491. Proceedings 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. 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. 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. Murray, L , S.H. Thomas, J. Schroeder, S. Kreider, Z. Du, J.M. Trojan and C. Fiore. 2011. Modeling the root-knot nematode/nutsedge pest complex: perspectives from weed science, nematology and statistics. Proceedings of the 2011 AgStat Conference (in press). Robbins, R. T., E. Shipe, P. Arelli, P. Chen, G. Shannon, K. M. Rainey, L. E. Jackson, E. E. Gbur, D. G. Dombek, & 1. 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. Abstracts Bernard, E.C., I.M. Trojan, and S.H. Thomas. 2011 . Nematode biodiversity at Otero Mesa, New Mexico, a pristine desert grassland. Journal of Nematology 43: (in press). Brito, IA R.A Stamler, S.H. Thomas, AP. Nyczepir, and D.W. Dickson. 2011 Distribution, hosts and identification of Meloidogyne partiryla in the USA. Nematropica 41: (in press). Kandouh, B. and B. Sipes. 2011. Red potato cultivar (Solanum tuberosum L.) susceptibility to the root-knot nematode Meloidogyne incognita. Phytopathology 101:Supplement. 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. 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. 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. 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. Makimoto, Y. and B. Sipes. 2011. Innate response in tissue cultured Anthurium andraeanum against Radopholus similis. Phytopathology 101:Supplement. 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. 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. 201 1. Reniform nematode reproduction on soybean cultivars and breeding lines in 2010. Proceedings of the Beltwide Cotton Conferences. Atlanta. Thomas, S.H., J.M. Trojan, and R.I. Heererna. 2011. Meloidogyne partiryla-induced changes in pecan growth and nutrient sequestration. Journal of Nematology 43: (in press).