Native Fusarium head blight resistance from winter wheat cultivars ‘Lyman,’ ‘Overland,’ ‘Ernie,’ and ‘Freedom’ mapped and pyramided onto ‘Wesley’-Fhb1 backgrounds

Abstract

Pyramiding QTL from multiple sources for FHB resistance presents an opportunity to enhance the FHB resistance of elite wheat germplasm. Mapping FHB resistance QTL directly in wheat breeding populations would eliminate the need for purpose-built mapping populations and thus accelerate marker-assisted pyramiding efforts. In this study, we demonstrate that multiple QTL for FHB resistance can be mapped directly in early-generation breeding populations by application of identical-by-descent (IBD)-based linkage mapping. IBD-based linkage analysis was conducted using 565 segregating F1 progeny derived from 28 four-way crosses among Fhb1 donor lines and multiple native sources of resistance including Lyman, Overland, Ernie, and Freedom. A total of 15 QTL for FHB resistance were mapped on chromosomes 1A, 1B, 2A, 3A, 3B, 4A, 4B, 4D, 5A, 6A, 6D, and 7D, including known loci Fhb1, Fhb5, and Rht-B1. QTL conferring native resistance in the cultivars Lyman and Overland are mapped for the first time in this study, including a QTL on chromosome 1AS (Qfhb.sdsu-1A) explaining between 4.5 and 9.9 % of the phenotypic variance in all evaluations. Marker haplotypes for these QTL regions can be used to conduct marker-assisted selection and fixation of resistance alleles in subsequent generations of these breeding populations.