Genetic mapping of resistance to Fusarium head blight in soft red winter wheat line NC13-20076

Fusarium head blight (FHB) infection causes yield loss, quality degradation, and the production of damaging mycotoxins in common wheat (Triticum aestivum L). Marker analysis suggests that NC13-20076 does not possess previously identified FHB resistance quantitative trait loci (QTL) screened for in eastern winter wheat germplasm. A doubled haploid population of 168 lines from the cross of GA06493-13LE6 and NC13-20076 was phenotyped in inoculated nurseries in six environments. Heading date, plant height, and visual ratings of Fusarium damage on heads were recorded in the field; percent Fusarium damaged kernels (FDK) and deoxynivalenol (DON) accumulation were recorded post-harvest. Interval and multiple QTL mapping were performed on each environment-by-trait combination. Plant height and heading date QTL were identified on chromosomes 4A, 5A, 6A, and 7B, and peak markers were used as covariates in mapping of disease response traits. Disease response QTL were identified on chromosomes 1A, 2A, 2B, 3A, 3B, 4A, 5A, 7A, and 7D. The largest percent variance (PV) QTL identified for FHB visual ratings (10.8%) and DON accumulation (10.1%) were found on chromosome 5A (QFvr.nc-5A, QDon.nc-5A). The largest PV (10.3%) QTL identified for FDK were found on 1A (QFdk.nc-1A). Disease response QTL for multi-environment scans of visual ratings, FDK, and DON accumulation accounted for 4.0%–10.8%, 4.1%–10.3%, and 4.9%–10.1% of the total variance, respectively. The present results indicate that NC13-20076 contains several FHB response QTL, which overlap with previously identified QTL and demonstrate the importance of NC13-20076 as a readily accessible source of FHB resistance.