Association Mapping and Genome-Wide Prediction of Fusarium Head Blight Resistance in Minnesota Wheat Lines

Abstract

Triticum aestivum L. (common wheat) is one of the top three global staple crops, with both record production and consumption forecasted by the USDA for 2021-22. The University of Minnesota’s Wheat Breeding program has developed wheat cultivars and conducted wheat breeding and genetics research for over a century. Breeding for disease resistance is a major priority. Fusarium head blight (FHB), or scab, is a fungal disease of wheat and other small grain crops causing significant yield and quality reduction. FHB has been a major focus for wheat breeding and research. Quantitative trait locus (QTL) mapping studies have identified hundreds of QTL, while only a handful have been successfully deployed in breeding. The University of Minnesota introduced resistant germplasm from Asia in the late 1980s. Genome-wide association mapping (GWAS) uses high density genetic markers and historic linkage disequilibrium to uncover genetic associations between genotypes and phenotypes. Through GWAS, this study identified QTL maintained in the program over decades of phenotypic and marker-assisted selection. Genome-wide selection (GS), a molecular marker-based method for improving quantitative traits, has shown promise for FHB resistance breeding. This study investigated strategies to implement genome-wide selection for FHB resistance during cultivar development. Genome-wide selection has the potential to reduce time and cost and accelerate the rate of genetic gain.