Abstract
Knowledge of genetic diversity and genes conferring disease resistance is essential for the effective use of wheat germplasm resistant to powdery mildew in breeding programs in southwest China. In this study, a collection of 140 common wheat varieties was evaluated for their resistance to powdery mildew in four different environments. Thirty-six varieties (25.71%) showed resistance in all four environments, and most of these varieties originated from the Guizhou Province. This collection was also scanned for molecular markers closely linked to the powdery mildew resistance genes. Most of the wheat varieties (79.86%) carried the resistance Pm30 gene locus. Genotyping by sequencing (GBS) was used to screen our collection against the whole genome. Finally, 6864 informative SNP markers were used to construct a consensus tree with 1000 bootstraps, which showed two groups based on their origins and the presence of the Pm21 gene locus. Our results provide useful information for breeding wheat resistant to powdery mildew in China, and they will likely contribute to the identification of new resistance genes in the future.