Quantitative trait loci associated with resistance to fusarium head blight in a CDC hughes x AAC concord derived wheat population
Berraies, S., Cuthbert, R., Knox, R.E., Ruan, Y., Henriquez, M.A., Burt, A., Kumar, S., Pozniak, C., N’Diaye, A. 2019. Quantitative trait loci associated with resistance to fusarium head blight in a CDC hughes x AAC concord derived wheat population. 1st International Wheat Congress Saskatoon, Canada, July 21-26, 2019.
Fusarium Head blight (FHB) of wheat caused predominantly by the pathogen Fusarium graminearum is the most challenging disease affecting wheat production in Western Canada. Genetic resistance to FHB is essential to reduce losses of grain yield and quality. Understanding the genetics and identifying molecular markers associated with FHB resistance is needed to select for resistance in early generation lines. From a cross between AAC Concord (Moderately susceptible to FHB) and CDC Hughes (Intermediate resistance to FHB), an initial set of 135 doubled haploid (DH) lines was generated and evaluated in 2016 for response to FHB in a corn spawn inoculated nursery located near Brandon MB. An additional 53 DH lines were developed from the same cross, and the larger set of 188 lines was further evaluated in 2017 and 2018 for FHB reaction in corn spawn inoculated nurseries located near Morden and Brandon MB. Continuous distributions of FHB incidence (Type I resistance) and severity (Type II resistance) indicated quantitative inheritance of both types of resistance. A linkage map of 9881 SNP (Infinium iSelect 90k SNP wheat array) markers was used to detect eight genomic regions responsible for FHB resistance. AAC Concord contributed favourable alleles on chromosomes 3D, 4B, 5B, and 7D, whereas CDC Hughes contributed resistant alleles on chromosomes 1A, 2A, 2D, and 5A. QTL associated with resistance to FHB incidence and severity co-located on chromosomes 1A, 2D, 4B, and 5B. The QTL on 4B which co-localise with Rht1 accounted for the most FHB incidence variation at 28.8% and the QTL on 5A explained the highest phenotypic variation for FHB severity at 24.5%. The SNP markers associated with resistance QTL could be utilized to facilitate combining these QTL and accelerating the development of FHB resistant adapted wheat cultivars.