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ARS Home » Midwest Area » St. Paul, Minnesota » Cereal Disease Lab » Research » Publications at this Location » Publication #331430
Title: Association mapping of leaf rust resistance loci in a spring wheat core collection

Author
item TURNER, MARGARET - University Of Minnesota
item Kolmer, James
item Pumphrey, Michael
item BULLI, PETER - Washington State University
item Chao, Shiaoman
item ANDERSON, JAMES - University Of Minnesota

Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2016
Publication Date: 11/2/2016
Citation: Turner, M.K., Kolmer, J.A., Pumphrey, M.O., Bulli, P., Chao, S., Anderson, J. 2016. Association mapping of leaf rust resistance loci in a spring wheat core collection. Theoretical and Applied Genetics. 130(2):345-361. doi: 10.1007/s00122-016-2815-y.

Interpretive Summary: Wheat is attacked by a fungus that is called Puccinia triticina, which is the cause of the disease wheat leaf rust. This disease occurs in the U.S. and world wide. In this study, a collection of spring wheat cultivars from North America and around the world were tested for resistance to the leaf rust disease. The resistance data was then used in combination with a set of 90 thousand DNA markers that covers all 21 chromosomes of the wheat genome. Correlations were made between the resistance data and the chromosome location of the DNA markers using a process called genome wide association mapping. This allowed the chromosome location of the resistance genes in the wheat collection to be determined. Five potentially new leaf rust resistance genes were identified in the study. Data from this study can be used to identify newe resistance genes that can be used to improve the leaf rust resistance in wheat in the US and worldwide.

Technical Abstract: Leaf rust is a common disease of wheat, consistently reducing yields in many wheat growing regions of the world. Although fungicides are commonly applied to wheat in the U.S., genetic resistance can provide less expensive, yet effective control of the disease. Our objectives were to map leaf rust resistance genes in a large core collection of spring wheat accessions selected from the United States Department of Agriculture-Agricultural Research Service National Small Grains Collection (NSGC), determine whether previously characterized race non-specific resistance genes could be identified with our panel, and evaluate the use of targeted panels to identify seedling and adult plant resistance (APR) genes. Association mapping detected five potentially novel leaf rust resistance loci on chromosomes 2BL, 4AS, and 5DL at the seedling stage, and 2DL and 7AS that conditioned both seedling and adult plant resistance. In addition, ten potentially novel race non-specific resistance loci conditioned field resistance and lacked seedling resistance. Analyses of targeted subsets of the accessions identified additional loci not associated with resistance in the complete core panel. Using molecular markers, we also confirmed the presence and effectiveness of the race non-specific genes Lr34, Lr46, and Lr67 in our panel. Although most of the accessions in this study were susceptible to leaf rust in field and seedling tests, many resistance loci were identified with AM. Through the use of targeted subset panels, more loci were identified than in the larger core panels alone.