1a. Objectives (from AD-416)
Objective 1: Identify and characterize unique resistance sources from landraces that are amenable for introgression into adapted cultivars. Multiple new sources of resistance are important because resilient resistance to rusts has been problematic due to the rapid evolution of new virulent races within the fungi, this means that continuous efforts are essential to stay ahead of new emerging virulence. Objective 2: Identify molecular markers to facilitate both incorporation of resistance into adapted cultivars, and for marker assisted selection (MAS).
1b. Approach (from AD-416)
Germplasm from the USDA-ARS National Small Grains Germplasm Collection (NSGC) will be screened utilizing Amplified Fragment Length Polymorphism (AFLP) and Simple Sequence Repeat (SSR) markers for cladistic analysis. Caldistic analysis will be used to determine if stem rust resistant germplasm arose from a monophyletic origin or if multiple sources of novel resistance are represented within the germplasm collection. Develop genetic mapping populations to characterize resistance alleles to Ug99 in resistant cultivars. Documents SCA with Washington State University.
3. Progress Report
Currently developing phylogenies of 750 NSGC material that has been screened in Kenya against Ug99 stem rust. The molecular phylogenies will be used to determine unique resistance sources for breeding and introgression into adapted cultivars. In collaboration with Li Huang Montana State University Bozeman Montana; Developed a genetic map in 182 F2 individuals from a cross with Hartog X Wampum. Hartog contains multiple seedling resistance and an adult plant resistant gene for Ug99 stem rust. This genetic map will help to identify seedling genes and make populations that only segregate for adult plant resistance. In collaboration with Mike Bohnman USDA-ARS Aberdeen, Idaho; genotyped 13 individuals that comprise the parents of multiple mapping populations that segregate for Ug99 stem rust resistance. This project will continue with our genotyping facility and current graduate student developing genetic maps from this material. Methods of monitoring for this project have included quarterly conference calls with all scientists and program leaders involved in the Stem Rust initiative. Multiple emails have been exchanged regarding specific projects, and results.