Identification of powdery mildew resistance loci in wheat by integrating genome-wide association study (GWAS) and linkage mapping

Publication date: Available online 9 April 2019Source: The Crop JournalAuthor(s): Genqiao Li, Xiangyang Xu, Chengcheng Tan, Brett F. Carver, Guihua Bai, Xuewen Wang, J. Michael Bonman, Yanqi Wu, Robert Hunger, Christina CowgerAbstractWheat powdery mildew (Blumeria graminis f. sp. tritici) is a disease of increasing importance globally due to the adoption of high yielding varieties and modern sustainable farming technologies. Growing resistant cultivars is a preferred approach to managing this disease, and novel powdery mildew resistance genes are urgently needed for new cultivar development. A genome-wide association study was performed on a panel of 1292 wheat landraces and historical cultivars using 5011 single nucleotide polymorphism (SNP) markers. Linkage disequilibrium (LD) analysis indicated that genome-wide LD decayed to 0.1 at 23 Mb. The association panel was evaluated for powdery mildew reactions to three powdery mildew inoculants, OKS(14)-B-3-1, OKS(14)-C-2-1, and Bgt15. Population structure analysis revealed seven subgroups in the panel. Association analysis using a mixed linear model (MLM) identified three loci for powdery mildew resistance on chromosome 2B, designated QPm.stars-2BL1, QPm.stars-2BL2, and QPm.stars-2BL3. To evaluate the efficacy of GWAS in gene discovery, QPm.stars-2BL2 was validated using F2 and F2:3 populations derived from PI 420646 × OK1059060-126135-3. Linkage analysis delimited the powdery mildew resistance gene in PI 420646 to an inte...
Source: The Crop Journal - Category: Food Science Source Type: research