Comparing Biparental and Association Mapping Techniques to Identify Leaf Rust Resistance in Diverse Wheat Accessions

Leaf rust is common in wheat, consistently reducing yields by 5-15% with higher losses recorded.  In hard red spring wheat growing regions of the U.S., farmers apply fungicides annually to mitigate crop losses, but genetic resistance can provide less expensive, effective control. Our objectives are to map leaf rust resistance genes and evaluate the utility of association and biparental mapping approaches. Six populations developed from selected diverse National Small Grains Collection lines were evaluated for seedling resistance, which has been mapped using bulk segregant analysis.  Two populations were developed for adult plant resistance, which will be mapped using recombinant inbred lines. Association mapping will be used to identify loci contributing to resistance in the diverse NSGC lines.  The goals of this project are to identify new resistance loci and effective combinations of genes, contribute to characterization of leaf rust resistance genes in global germplasm, and compare biparental and association mapping approaches.