ARS | Publication request: Evaluation of soybean germplasm collections for disease reaction and prospects for development of disease resistant varieties

Submitted to: National Soybean Rust Symposium
Publication Type: Abstract Only
Publication Acceptance Date: December 14, 2007
Publication Date: December 12, 2007
Citation: Walker, D.R. 2007. Evaluation of soybean germplasm collections for disease reaction and prospects for development of disease resistant varieties. 2007 National Soybean Rust Symposium. December 12-14, 2007. Louisville, KY. pp. 1-31.

Technical Abstract: Accurate evaluation of germplasm accessions for resistance to soybean rust is complicated by the influence of environmental conditions, stage of plant development, other pests and pathogens, geographical and temporal genetic variation among Phakopsora pachyrhizi isolates, and interactions among these factors. An additional complication in North America is the need for field screening of germplasm in the Southeast, where annual rust epidemics are likely to occur, but often develop late in the growing season. These challenges are being addressed through collaboration among researchers from several public institutions to identify sources of rust resistance genes that are likely to be effective in most or all regions of production. Building on previous evaluations, the current effort has successfully identified or confirmed several dozen accessions displaying resistance against rust isolates from multiple locations in the Southeast. There is a simultaneous effort to transfer resistant genes from these accessions to the genetic backgrounds of high-yielding and agronomically superior cultivars and breeding lines adapted to North America. Pyramiding major resistance genes with quantitative resistance genes is an important objective because it is likely to increase the durability of resistance. Development of rust-resistant cultivars with good yields and resistance to other diseases and pests will be more efficient if breeders are able to supplement conventional breeding approaches with marker-assisted selection and innovative phenotypic assays for resistance.