Mapping quantitative trait loci for fusarium head blight resistance in Canada Western Red Spring wheat Carberry

Fusarium head blight (FHB) is a major disease of wheat causing significant losses in grain yield and quality. Growing resistant cultivars is one of the best ways to manage the disease. Breeding for FHB resistance to develop resistant cultivars has been an ongoing practice by the wheat breeding program at AAFC Swift Current. This research was conducted to map and identify SNP markers associated with quantitative trait loci (QTL) controlling FHB resistance in a moderately resistant and widely grown Canadian spring wheat cultivar, Carberry. A doubled haploid (DH) population consisting 180 lines generated from a Carberry by Vesper cross was phenotyped for FHB incidence and severity at Morden, MB in 2015 and 2016, Bratt’s Lake, SK in 2015 and Brandon, MB in 2016. The DH lines were genotyped with the 90K iSelect SNP genotyping assay (Illumina Inc., San Diego, CA) and the chromosomal positions of loci and SNP markers associated with FHB resistance were identified by performing multiple QTL analysis using MapQTL.6®. The distribution of incidence and severity were continuous. Transgressive segregant lines more resistant than Carberry were observed in the population indicating both parents contributed to resistance. Significant QTL associated with FHB resistance components were detected on chromosomes 1A, 2B, 3B, 4B and 6B. Carberry contributed the resistance alleles for 1A, 3B and 4B for FHB incidence and severity, and Vesper contributed the resistance alleles for 2B QTL for FHB incidence and 6B QTL for FHB severity. The QTL on 1A and 3B were detected in all environments, the 4B QTL in two environments and the 2B and 6B QTL each in one environment. The 1A QTL explained phenotypic variation approaching 13 % in FHB severity and the 3B QTL up to 22.7 %. These findings will help to understand the resistance in Carberry and develop markers for maker assisted selection.