Project Number: 3611-22000-021-09
Project Type: Specific Cooperative Agreement

Start Date: Jul 01, 2012
End Date: Jun 30, 2015

Objective:
To provide support for collaborative field and greenhouse research to identify and characterize resistance to soybean rust and other economically important diseases in the USDA-ARS Soybean Germplasm Collection and in breeding populations developed from crosses to sources of resistance. Soybean germplasm accessions and breeding lines will be assayed for resistance or tolerance to soybean rust and to other diseases for which natural epidemics occur in the field. Genes associated with resistance will be mapped and resistant breeding lines will be selected for promising agronomic appearance and performance.

Approach:
Plant introductions (PIs) from the USDA-ARS Soybean Germplasm Collection in Urbana, IL will be planted in small, replicated field plots at the North Florida Research and Education Center (NFREC) to test their resistance to the local population of Phakopsora pachyrhizi, the primary fungus that causes soybean rust. In seasons when the local rust epidemic is negligible, supplementary inoculations with spores collected from infected plants at the NFREC may be used to promote disease pressure in the experimental plots. Natural infections with pathogens causing foliar diseases like Cercospora blight and frogeye leaf spot, or soilborne diseases like Phytophthora root and stem rot will be used to identify germplasm with apparent resistance to those pathogens, and breeding populations segregating for disease symptoms. After resistance has been confirmed with assays conducted under controlled conditions, DNA markers will be used to map resistance genes in segregating populations and inbred lines segregating for differential resistance reactions will be developed as tools for studying genes and proteins involved in resistance to the pathogens.