Stripe rust resistance genes in U.S. wheat cultivars and breeding lines identified by molecular markers and genome-wide association studies

Authors: LIU, L - Washington State University; MU, J - Washington State University; LIU, Y - Washington State University; WANG, M - Washington State University; See, Deven; Chen, Xianming

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary: Stripe rust is one of the most destructive diseases of wheat in the United States. To identify genes for effective stripe rust resistance in U.S. wheat, 616 spring wheat and 857 winter wheat varieties and breeding lines were studied using a genome-wide association approach and with markers for important previously reported genes. The accessions were tested for stripe rust response at seedling stage in a greenhouse with multiple races of the pathogen and at adult-plant stage in multiple field environments under natural infections of the pathogen, and also tested using a genotyping by multiplexed sequencing platform. In the spring panel, a total of 37 loci on 15 chromosomes (1A, 1B, 2A, 2B, 2D, 3B, 3D, 4A, 4B, 5A, 5B, 6B, 6D, 7A, and 7D) for resistance to stripe rust were detected including 10 new loci. In the winter panel, a total of 51 loci on 19 chromosomes (1A, 1B, 1D, 2A, 2B, 2D, 3A, 3B, 3D, 4A, 4B, 5A, 5B, 5D, 6A, 6B, 7A, 7B, and 7D) were associated to stripe rust resistance, including at least 4 new loci. The frequencies of the resistant alleles of these loci in various regional nurseries indicated different use intensities in breeding programs in different regions. The information on wheat varieties with identified resistance genes can be used for selecting and deploying resistant varieties to manage stripe rust. The resistance loci and their markers should be useful in breeding programs for continually improving stripe rust resistance.

Technical Abstract: Stripe rust (caused by Puccinia striiformis f. sp. tritici) is one of the most destructive diseases of wheat in the United States. To identify genes for effective stripe rust resistance in U.S. wheat, 616 spring wheat and 857 winter wheat cultivars and breeding lines were studied using a genome-wide association approach and with markers for important previously reported genes. The accessions were phenotyped for stripe rust response at seedling stage in a greenhouse with multiple races of the pathogen and at adult-plant stage in multiple field environments under natural infections of the pathogen, and genotyped using a genotyping by multiplexed sequencing platform. In the spring panel, a total of 37 loci on 15 chromosomes (1A, 1B, 2A, 2B, 2D, 3B, 3D, 4A, 4B, 5A, 5B, 6B, 6D, 7A, and 7D) for resistance to stripe rust were detected including 10 new loci. In the winter panel, a total of 51 loci on 19 chromosomes (1A, 1B, 1D, 2A, 2B, 2D, 3A, 3B, 3D, 4A, 4B, 5A, 5B, 5D, 6A, 6B, 7A, 7B, and 7D) were associated to stripe rust resistance, including at least 4 new loci. The frequencies of the resistant alleles of these loci in various regional nurseries indicated different use intensities in breeding programs in different regions. The information on wheat cultivars with identified resistance genes can be used for selecting and deploying resistant cultivars to manage stripe rust. The resistance loci and their markers should be useful in breeding programs for continually improving stripe rust resistance.