Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/27/1998
Publication Date: N/A
Technical Abstract: Degrees of resistance to Sclerotinia stem rot [Sclerotinia sclerotiorum (Lib.) de Bary], (SSR) have been identified in soybean [Glycine max (L.) Merr.] accessions and cultivars in the United States in field and greenhouse evaluations. The purpose of this study was to determine number of loci controlling SSR resistance in soybean cultivars Asgrow A2506 (A2506) and Northrup King NK S 19-90 (NKS19-90). Data obtained from greenhouse evaluations from three crosses were used to calculate the goodness of fit for classical genetic models in the F2 and F3 generations and to estimate broad and narrow sense heritabilities. Results suggest at least two recessive genes control resistance to S. sclerotiorum in soybean cultivars A2506 and NKS19-90. All broad sense heritability estimates (.0.89) based on the F2:3 family means were higher than the estimates based on F2 plant basis. This presages selection for resistance to S. sclerotiorum in soybean on based on F2:3 family means evaluation would be more efficient and valuable to breeders selecting for resistance to S. sclerotiorum in soybean.