Location: Cereal Crops ResearchTitle: Genome wide association study of seedling and adult plant leaf rust resistance in elite spring wheat breeding lines
|GAO, LIANGLIANG - University Of Minnesota|
|TURNER, M - University Of Minnesota|
|Kolmer, James - Jim|
|ANDERSON, JAMES - University Of Minnesota|
Submitted to: PLoS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2016
Publication Date: 2/5/2016
Publication URL: http://handle.nal.usda.gov/10113/62022
Citation: Gao, L., Turner, M.K., Chao, S., Kolmer, J., Anderson, J.A. 2016. Genome wide association study of seedling and adult plant leaf rust resistance in elite spring wheat breeding lines. PLoS ONE. 11(2):e0148671.
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 mostly from North America 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. Two 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 an important disease, threatening wheat production annually. Identification of resistance genes or QTLs for effective field resistance could greatly enhance our ability to breed durably resistant varieties. We applied a genome wide association study (GWAS) approach to identify resistance genes or QTLs in 338 spring wheat breeding lines from public and private sectors that were predominately developed in the Americas. A total of 46 QTLs were identified for field and seedling traits and approximately 20-30 confer field resistance in varying degrees. The 10 QTLs accounting for the most variation in field resistance explained 26-30% of the total variation (depending on traits: percent severity, coefficient of infection or response type), similarly the 10 QTLs accounting for most of the variation in seedling resistance to different races explained 24-34% of the variation, after correcting for population structure. Two potentially novel QTLs (QLr.umn-1AL, QLr.umn-4AS) were identified. Identification of novel genes or QTLs and validation of previously identified genes or QTLs for seedling and especially adult plant resistance will enhance understanding of leaf rust resistance and assist breeding for resistant wheat varieties. We also developed computer programs to automate field and seedling rust phenotype data conversions. This is the first GWAS study of leaf rust resistance in elite wheat breeding lines genotyped with high density 90K SNP arrays.