Precise Mapping of Hessian Fly Resistance Gene from Spring Wheat ‘WA8076' Via 90K SNP Assay.

Hessian fly (HF) infestations continue to cause significant economic losses in spring wheat producing areas in the Pacific Northwest (PNW) of the United States. Genetic resistance is the most credible approach to reducing yield losses caused by HF and outpace biotype evolution. The primary goals of this study were to determine the chromosomal location of the Hessian fly resistance gene in the elite wheat germplasm ‘WA8076’, and to identify ‘breeder-friendly’ molecular markers tightly linked to the target gene. A doubled haploid (DH) mapping population consisting of 310 individuals was completed by crossing two elite spring wheat lines; ‘WA8076’, and ‘HT080158LU’. Seedling assessment for Hessian fly response of the mapping population progeny was conducted at the University of Idaho (UI) using a local mixed-biotype field population maintained in the lab. The DH population was genotyped with 90K SNP markers using the Illumina Infinium platform. A single Hessian fly resistance gene (HFR) from ‘WA8076’ was detected on the distal region of chromosome 6BS, flanked by two SNP markers IWB71431 and IWB61175 at a distance of 2.8 and 5.4 cM. The closely linked SNP markers identified in this study will provide an effective tool to accurately identify, select, and integrate the HF-resistance gene into existing wheat cultivars. Furthermore, the high-density genetic map offers the necessary basis needed for map-based cloning of the Hessian fly resistance gene.