Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2015
Publication Date: 3/10/2015
Citation: Naruoka, Y., Garland Campbell, K.A., Carter, A. 2015. Genome-wide association mapping for stripe rust (Puccinia striiformis F. sp. tritici) in US Pacific Northwest winter wheat (Triticum aestivum L.). Field Crops Research. doi: 10.1007/s00122-015-2492-2. Interpretive Summary: The problem is that although stripe rust resistance loci have been identified in other environments, specific knowledge about the number and location of stripe rust resistance genes effective in the Pacific Northwest was lacking. Stripe rust is a severe problem for producers in the Pacific Northwest and breeders have incorporated a several resistance genes. This research was initiated to identify specific loci and their interactions that resulted in stripe rust resistance. An association mapping panel was constructed based on breeding material from major PNW wheat breeding programs. Molecular markers, including both single nucleotide polymorphisms and SSR markers was assayed for association with stripe rust resistance. Potential novel and known QTL for race-specific all-stage and adult plant resistance to stripe rust were identified by genome-wide association mapping in the US PNW winter wheat accessions.Wheat breeders now have some good molecular tools to select for winter survival in wheat.
Technical Abstract: Stripe rust (Puccinia striiformis F. sp. tritici; also known as yellow rust) is a globally devastating disease of wheat (Triticum aestivum L.) and a major threat to wheat production in the US Pacific Northwest (PNW), therefore both adult plant and all-stage resistance have been introduced into the winter wheat breeding programs in the PNW. The goal of this study was to identify quantitative trait loci (QTL) and molecular markers for these resistances through genome-wide association (GWAS) mapping in winter wheat accessions adapted to the PNW. Stripe rust response for adult plants was evaluated in naturally occurring epidemics in a total of nine environments in Washington State, USA. Seedling response was evaluated with three races under artificial inoculation in the greenhouse. The panel was genotyped with the 9K Illumina Wheat single nucleotide polymorphism (SNP) array and additional markers linked to previously reported genes and QTL for stripe rust resistance. The population was grouped into three sub-populations. Markers linked to Yr17 and previously reported QTL for stripe rust resistance were identified on chromosomes 1B, 2A, and 2B. Potentially novel QTL associated with race-specific seedling response were identified on chromosomes 1B and 1D. Potentially novel QTL associated with adult plant response were located on chromosomes 2A, 2B, 3B, 4A, and 4B. Stripe rust was reduced when multiple alleles for resistance were present. The resistant allele frequencies were different among sub-populations in the panel. This information provides breeders with germplasm and closely linked markers for stripe rust resistance to facilitate the transfer of multiple loci for durable stripe rust resistance into wheat breeding lines and cultivars.