QTL Analysis of Common Bunt Resistance in the ‘Kenyon'/86ISMN 2137 Mapping Population

Common bunt is an important disease of wheat caused by Tilletia laevis and T. tritici. Host resistance has been utilized to manage common bunt on the Canadian prairies for decades. Resistance to common bunt is conditioned by single, race-specific Bt genes that impart near-immune levels of  resistance. The hard red spring wheat variety ‘Neepawa’ possesses partial resistance to common bunt. ‘Neepawa’ was a widely grown variety in the late 1980s to early 1990s and is an important ancestor of current western Canadian hard red spring wheat varieties. Common bunt resistance is being studied in the ‘Kenyon’/86ISMN 2137 mapping population. ‘Kenyon’ has the pedigree ‘Neepawa’*5/‘Buck Manantial’ and possesses common bunt resistance from ‘Neepawa’. The ‘Kenyon’/86ISMN 2137 linkage map consists of over 3,000 single nucleotide polymorphism (SNP), simple sequence repeat (SSR), and Diversity Array Technology (DArT) markers. The mapping population was tested for common bunt reaction in Lethbridge, AB and Swift Current, SK over the 2012 growing season. ‘Kenyon’ contributed QTL for bunt resistance were on chromosomes 2B and 6A. The chromosome 2B QTL was significant in the mean dataset over environments and in the Swift Current 2012 dataset, while the chromosome 6A QTL was significant in the mean dataset over environments and in the Lethbridge 2012 dataset. Common bunt data will be collected in additional environments with the goal of detecting additional QTL and identifying the QTL with the largest effect on common bunt reaction. The detected QTL are expected to be widely deployed in western Canadian wheat germplasm and will be targets for marker-assisted selection.