Genome-wide association mapping of native QTLs for Fusarium head blight resistance in US winter wheat

A genome-wide association study using 90 K wheat SNP arrays identified nine QTLs with 38 SNP markers significantly associated with Fusarium head blight resistance in US wheat. Six putative novel QTLs were identified from the US wheat with three for type II resistance, two for low DON and FDK and one for all three traits. Wheat Fusarium head blight (FHB) is a devastating disease of wheat worldwide. Growing FHB-resistant wheat is the most effective and eco-friendly approach to reduce the losses. To identify native FHB resistance quantitative trait loci (QTLs), a population of 201 US winter wheat breeding lines and cultivars were genotyped using 90 K wheat single nucleotide polymorphism (SNP) arrays and phenotyped for the percentage of symptomatic spikelets (PSS) in a spike in three greenhouse experiments, and for PSS, Fusarium damaged kernels (FDK) and deoxynivalenol (DON) content in two field experiments. Genome-wide association studies (GWAS) identified 38 SNPs that were significant for at least two of the three traits or a single trait in at least two experiments on chromosomes 1A, 1D, 2B, 3A, 3B, 4A, 5B and 5D. Among them, QPss.hwwg-1AS, QPss.hwwg-1DS and QPss.hwwg-3AL are likely novel QTLs for reduced PSS from US winter wheat, and QFDon.hwwg-4AL, QFDon.hwwg-5BL and QFDon.hwwg-5DL are novel QTLs for low FDK and DON. Among them, only QFDon.hwwg-5BL had significant effects on all the three FHB traits. Most of these QTLs showed additive effects. Among the tested accessions, hard winter wheat 'T153,' 'T154' and 'OK05128' harboring all resistance marker alleles for low PSS, FDK and DON, therefore, they are good resistant parents for improving FHB resistance.