Genome-Wide Association Studies and Prediction of Tan Spot () Infection in European Winter Wheat via Different Marker Platforms.

Tan spot, caused by the fungus (), is a severe foliar disease of wheat ( L.). Improving genetic resistance is a durable strategy to reduce -related losses. Here, we dissected -infection's genetic basis in 372 European wheat varieties via single sequence repeats (SSR) in addition to 35k and 90k single nucleotide polymorphism (SNP) marker platforms. In our phenotypic data analyses, infection showed a significant genotypic variance and a significant negative correlation with plant height. Genome-wide association studies revealed a highly quantitative nature of infection and identified two quantitative trait loci (QTL), viz., and , which imparted 21.23 and 5.84% of the genotypic variance, respectively. Besides, the gene showed a strong allelic influence on the resistance scores. Due to the complex genetic nature of the infection, the potential of genome-wide prediction (GP) was assessed via three different genetic models on individual and combined marker platforms. The GP results indicated that the marker density and marker platforms do not considerably impact prediction accuracy (~40-42%) and that higher-order epistatic interactions may not be highly pervasive. Our results provide a further understanding of -infection's genetic nature, serve as a resource for marker-assisted breeding, and highlight the potential of genome-wide selection for improved resistance.