Project Number: 5348-22000-015-03
Start Date: Sep 15, 2011
End Date: Sep 14, 2016
1. For developing cultivars with effective and durable resistance to stripe rust, it is essential to understand virulence compositions in the pathogen populations and dynamics of virulences. To obtain such information, stripe rust will be monitored by Pakistani scientists in commercial fields and disease and breeding nurseries during the wheat growing season. Stripe rust infected leaf samples will be collected and send to the ARS Wheat Genetics Unit at Pullman, Washington for characterizing virulences and identifying races. We will accept up to 50 samples. Upon receiving the samples, we will start to increasing spores if possible. Our standard procedures will be used to recover stripe rust, increase spores and test on differentials. Our newly established set of 20 single-gene differentials will be used for testing every isolates. To identify genetic changes that may not be detected by the stripe rust resistance genes in the differentials, we will extract DNA from spores of the Pakistan isolates. Our recently developed molecular markers (EST-SSR) will be used to characterize the isolates to identify new genotypes and determine genetic relationships among isolates. 2. To help Pakistani scientists in developing wheat cultivars with effective and durable resistance to stripe rust, we will evaluate advanced/elite breeding lines of wheat developed or used by Pakistani breeding programs. Wheat lines will be tested with selected U.S. and Pakistan stripe rust races in the seedling stage under controlled greenhouse conditions. We will also test the Pakistan wheat lines in field under natural infection of stripe rust at Pullman and Mt. Vernon, WA. Comparison of stripe rust data of field and greenhouse tests will allow preliminarily determining the presence or absence of high-temperature adult-plant (HTAP) resistance in the wheat lines. To clarify postulated genes, we will use molecular markers that are available for many stripe rust resistance genes or QTL. Our focus will be on genes and gene combinations conferring effective resistance. For wheat germplasm that potentially have new genes for effective resistance based on all above tests, we will conduct genetic and molecular mapping studies to identify the genes and develop markers to be used in marker-assisted selection. 3. To sustain long-term efforts of improving wheat for rust resistance, students and scientists need to get first-hand experience with stripe rust. We plan to provide training to 2-3 Pakistani scientists and students. Our training will focus on all aspects related to disease monitoring, race identification and survey, germplasm screening, genetics and molecular mapping of resistance genes, and molecular characterization of stripe rust populations.