1a.Objectives (from AD-416)
The objective of this cooperative research project is to search for and identify resistance sources of grain legumes to diseases caused by Sclerotinia spp. and related pathogens by screening the commercial cultivars and core germplasm collections of peas, chickpeas and lentils. Develop efficient field and greenhouse screening techniques suitable for each of the grain legume crops. Determine the genetic nature of the identified resistance by using traditional and modern genetic techniques including hybridization and progeny analysis, gene cloning and disruption. Investigate genetic variability of the pathogens. Formulate an approach to incorporate the resistance into future cultivars of peas, chickpeas and lentils for efficient management of the diseases in grain legume production. Publish findings in international journals.
1b.Approach (from AD-416)
Compare various techniques for inoculum production and inoculation onto peas, chickpeas, and lentils. Select the best technique to screen the commercial cultivars and core germplasm collections of the grain legumes. Evaluate plant growth habit in relation to resistance to white mold and related diseases. Use traditional genetic techniques such as hybridization to determine the inheritance pattern of the identified resistance. Employ modern genetic techniques to locate resistance genes in grain legumes, and to isolate and disrupt the pathogenicity gene in the pathogens. Utilize vegetative compatibility grouping technique and DNA fingerprinting to determine genetic variability of Sclerotinia spp and related pathogens. Document the SCA with the Department of Plant Pathology at Washington State University, Pullman. Formerly 5348-21000-014-01S (5/08).
Research efforts of this Specific Research Agreement were to develop specific and high polymorphic DNA markers for studying population genetics of the recently described pathogen on chickpea, Sclerotinia trifoliorum. Significant accomplishments were achieved in developing specific microsatellite markers. Microsatellites are ideal genetic markers for population genetic studies. Using a microsatellite-enrichment of genomic DNA library, thirty-three polymorphic microsatellite loci were developed for Sclerotinia trifoliorum. The microsatellite markers showed various levels of polymorphism (3 to 12 alleles per locus and expected heterozygosity ranging from 0.26 to 0.90) in 42 isolates of S. trifoliorum. Many of the markers are also applicable to the closely related species S. sclerotiorum and S. minor. However, all the locus-specific markers (except one) did not amplify DNA of S. homoeocarpa. These markers are useful for population structure assessment and ecological analyses of S. trifoliorum and other Sclerotinia species. The cooperator’s performance is monitored by regular visits to the cooperator’s research facilities, which are located at Washington State University. During these visits the project plan is discussed, program goals are confirmed, and data is analyzed and interpreted with respect to realizing the objectives of the research program.