Molecular mapping of QTL for Fusarium graminearum biomass and deoxynivalenol accumulation
Berraies, S., Knox, R., Cuthbert, R., Henriquez, M.A., Ouellet, T., Balcerzak, M., Blackwell, B., Bhadauria, V., Meyer, B., Ruan, Y., and Sangha, J. 2018. Molecular mapping of QTL for Fusarium graminearum biomass and deoxynivalenol accumulation in spring wheat grain. Joint 9th Canadian Workshop on Fusarium Head Blight and 4th Canadian Wheat Symposium, Winnipeg, November 19-22, 2018.
Fusarium graminearum a causal agent of fusarium head blight (FHB) of wheat produces deoxynivalenol (DON), the predominant trichothecene mycotoxin in contaminated wheat grain that, when ingested, causes a wide range of acute and chronic effects in humans and animals. Understanding the genetics and identifying molecular markers associated with low FHB symptoms and DON levels is needed to select for resistance breeding in early generation lines. In this study grain samples from 178 doubled haploid (DH) lines derived from the elite cross Carberry/AC Cadillac were harvested from a fusarium-inoculated nursery near Morden (MB). A qPCR-based analytical method was applied to quantify the biomass of F. graminearum in grain of each DH line. The DH lines were also evaluated for DON accumulation. We investigated the correlation between Fusarium biomass and DON levels, and identified molecular markers associated with low Fusarium infection and DON. A significant correlation was observed between the fungal biomass and the amount of DON produced (r = 0.749, P<0.0001, n = 178). Composite interval mapping detected QTL on chromosomes 3B, 4A, 5BS and 5BL for low DON and QTL on chromosomes 3B, 4B, 5BS, 5BL, and 7A for low Fusarium biomass. Resistance to the two traits co-located on chromosomes 3B, 5BS, and 5BL. The QTL on 4B accounted for the most Fusarium biomass variation at 9.5%. The QTL on 3B explained higher phenotypic variation for DON at 14.5% than for Fusarium biomass at 6.5%. This information will be valuable in marker-assisted breeding for lower DON accumulation in wheat grain.