Project Number: 6402-21220-010-00
Project Type: Appropriated

Start Date: May 19, 2008
End Date: May 18, 2013

Objective:
Determine the inheritance and identify molecular markers linked to genes controlling resistance to Macrophomina phaseolina; identify differential sources of resistance/tolerance to Asian soybean rust and identify molecular markers associated with responsible genes; identify differential sources of resistance/tolerance and associated molecular markers for the Phomopsis/Diaporthe complex; and conserve available genetic diversity in genus Glycine; acquire and characterize new accessions to enhance the southern USDA Soybean Germplasm Collection.

Approach:
Phenotype an F5 derived recombinant inbred (RIL) population segregating for resistance to Macrophomina phaseolina in replicated, multi-location, multi-year field tests, create a molecular map of the RIL population, determine the inheritance of resistance and identify molecular markers linked to resistance loci. Develop populations segregating for resistance to Phakopsora pachyrhizi. Phenotype selected populations in the field in Paraguay, determine whether resistance loci represent new genes, identify molecular markers linked to any new resistance loci, develop RIL populations as needed, and select for enhanced resistant germplasm. Evaluate lines identified and evaluated in Paraguay in the quarantine facility at Stoneville against US and Mississippi ASR isolates. Screen selected lines from the USDA-ARS germplasm collection for resistance to Phomopsis seed decay (PSD). Create molecular mapping populations, determine whether resistance loci represent new genes, identify linked molecular markers, and determine the inheritance of any new resistance genes. Incorporate novel resistance genes into germplasm readily suitable for use in the breeding industry. Characterize, pure-line, maintain purity, and increase seed of the approximately 6,500 MG V-VIII accessions of the USDA-ARS Soybean Germplasm Collection grown at Stoneville, MS. Submit pure-lined and detailed characterization of new accessions to the collection. Provide quality seed to the collection for use by soybean researchers worldwide and to maintain viable seed in the collection.