abstract
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Fusarium head blight (FHB) is an important disease of wheat, which is primarily caused by Fusarium graminearum in Canada. FHB reduces grain yield and quality, and results in the presence of the mycotoxin deoxynivalenol in the grain. FHB resistance is a quantitative trait with numerous QTL have been described, each having a small effect on phenotype. Fhb2 was previously described in the cross BW278/‘AC Foremost’ and was one of the first FHB resistance QTL identified in the Chinese spring wheat variety ‘Sumai 3’. Fhb2 has been mapped relative to microsatellite markers but little research has been conducted to map the gene using a dense genetic map. In this study, Fhb2 was retained in a BC2-derived population (‘Shaw’*3/BW278), in which BW278 carries Fhb2 and the Canadian hard red spring wheat variety ‘Shaw’ is susceptible to FHB. One hundred eighty-eight BC2F3 plants fixed for crossovers on chromosome 6B were selected for the study. The population was tested with SNP markers and phenotyped for FHB resistance in field nurseries in 2018. Histograms of the phenotypic data were not bi-modal, which prevented categorical scoring of the phenotypic data. Preliminary QTL mapping results indicate Fhb2 maps near the centromere and is most likely on the short arm as was previously described. This location will likely present difficulties for fine mapping Fhb2 based upon genetic recombination. Haplotype analysis identified the SNP markers for marker-assisted selection in breeding programs.