Project Number: 5348-21000-030-00
Start Date: Mar 22, 2013
End Date: Mar 21, 2018
Objective 1. We will evaluate a total of 6,356 accessions for resistance to freezing injury, Fusarium crown rot, lesion nematodes, cyst nematodes, and stripe rust. We will conduct these evaluations using facilities at WSU, including controlled environments in the WSU Plant growth facility and at the Spillman Agronomy Farm. We will use the genomic information generated by the T-CAP for the existing core collection to link phenotypes to genotypes. We will also screen germplasm from U.S. regional nurseries. These selections will be genotyped to determine relationships and, on the theory that genetic control of resistance will be different among genetically diverse genotypes, traits from the most diverse will be introgressed into adapted cultivars, and germplasm adapted to various regions of the U.S. carrying unique new sources of resistance and molecular markers that can be used to select for these new resistance loci. Objective 2. Specific areas that are being targeted in SNP development include identification of SNP markers linked to stem and stripe rust resistance genes, and identification of SNP in wheat responsible for adaptation. The current small grains single plant core collections are being evaluated for SNP linkages to drought, stripe, leaf and stem rust response. As new, verified markers are identified, they will be made available to the customers of the genotyping laboratory as applicable to the customers’ research and breeding objectives. Our goal is to transition away from single gene selection using SSR markers and incorporate genome selection utilizing SNPs through SNP-chip platforms. Objective 3. Pathways and mechanisms controlling drought and cold tolerance, pre-harvest sprouting, and rust resistance in wheat will be elucidated. Indirect selection for tolerance to freezing and to drought based on physiological traits associated with drought and freezing tolerance will be carried out as part of the selection process. Plant lines will be selected for higher water use efficiency, deeper roots, and higher photosynthetic efficiency to develop better grain yield and grain-filling under drought stress. Transcriptome analysis will be used to identify pathways and mechanisms responding to freezing stress and stripe rust. Key genes will be identified and their expression monitored under stress conditions, thereby identifying plant lines differing in their abilities to respond to parts of the freezing or infection process. Variation in sensitivity to plant hormones will be investigated as a means to control and improve seedling emergence and preharvest sprouting tolerance. These different abilities and sensitivities will be genetically combined, resulting in improved stress tolerance.