Genetic Analyses of Rust Resistance in Aegilops tauschii

Project Summary:
Diverse genetic components of disease resistance in wheat are critical to ensure long-term food security. Aegilops tauschii was documented to preserve many disease resistance genes that are not present in bread wheat. Hundreds of Aegilops tauschii accessions have been collected and characterized for their resistance to leaf rust, stripe rust, stem rust, Greenbug, etc. In the previously IUCRC supported projects, we have established multiple Ae. tauschii populations by crossing different accessions from the collection, and used some of these populations to identify an important leaf rust resistance gene, Lr42, as well as mapped a few other leaf rust resistance genes. Leaf rust is a prevalent wheat disease limiting wheat production worldwide. To date, six leaf rust resistance genes were cloned and published. More resistance genes are needed to combat fast evolving fungal pathogens. Based on our preliminary data and available genetic materials, we propose to use the genetic mapping approaches established during previous projects to continue explore new leaf rust resistance genes in the Ae. tauschii collection, focusing on durable adult plant resistance genes. Genetic mapping will localize resistance genomic loci, providing information for the comparison with known resistance genes. Novel resistance genes will be further genetically mapped at a finer scale, which will result in genetic markers that are tightly linked with resistance genes. Resistant plants that carry resistance genes will be backcrossed to elite wheat varieties to facilitate the use of these resistance genes in wheat. The outcome will provide valuable genetic resources and information for breeding leaf rust resistant wheat varieties for profitable and high-quality wheat crop production. Meanwhile, the project will create a number of populations by crossing core Ae. tauschii accessions. The populations will be useful for genetic analysis of any traits of interest.