Author
MULETA, KEBEDE - WASHINGTON STATE UNIVERSITY | |
BULLI, PETER - WASHINGTON STATE UNIVERSITY | |
RYNEARSON, SHERI - WASHINGTON STATE UNIVERSITY | |
Chen, Xianming | |
PUMPHREY, MICHAEL - WASHINGTON STATE UNIVERSITY |
Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/1/2017 Publication Date: 6/7/2017 Citation: Muleta, K.T., Bulli, P., Rynearson, S., Chen, X., Pumphrey, M. 2017. Loci associated with resistance to stripe rust (Puccinia striiformis f. sp. tritici) in a core collection of spring wheat (Triticum aestivum). PLoS One. 12(6):e0179087. Interpretive Summary: Stripe rust remains one of the most significant diseases of wheat worldwide. We investigated stripe rust resistance by genome-wide association analysis (GWAS) in 959 spring wheat accessions from the Unites States Department of Agriculture-Agricultural Research Service National Small Grains Collection, representing major global production environments. The wheat panel was characterized for stripe rust resistance in multi-environment field trials and seedling stage under greenhouse conditions. A genome-wide set of 5,619 informative simple nucleotide polymorphism (SNP) markers were used to examine the population structure, linkage disequilibrium and marker-trait associations in the panel. Based on model-based analyses of population structure and clustering algorithm, the accessions were clustered into two major subgroups, which were largely separated according to geographic origin and improvement status of the accessions. A significant correlation was observed between the population sub-clusters and response to stripe rust infection. We identified 11 and 7 genomic regions with significant associations with stripe rust resistance at adult plant and seedling stages, respectively. The regions harboring all, except three, of the quantitative trait loci (QTL) identified from the field and greenhouse studies overlap with positions of previously reported QTL. Further work should aim at validating the identified QTL using proper germplasm and populations to enhance their utility in marker assisted breeding. Technical Abstract: Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss. (Pst) remains one of the most significant diseases of wheat worldwide. We investigated stripe rust resistance by genome-wide association analysis (GWAS) in 959 spring wheat accessions from the Unites States Department of Agriculture-Agricultural Research Service National Small Grains Collection, representing major global production environments. The panel was characterized for field resistance in multi-environment field trials and seedling resistance under greenhouse conditions. A genome-wide set of 5,619 informative SNP markers were used to examine the population structure, linkage disequilibrium and marker-trait associations in the germplasm panel. Based on model-based analysis of population structure and hierarchical Ward clustering algorithm, the accessions were clustered into two major subgroups. These subgroups were largely separated according to geographic origin and improvement status of the accessions. A significant correlation was observed between the population sub-clusters and response to stripe rust infection. We identified 11 and 7 genomic regions with significant associations with stripe rust resistance at adult plant and seedling stages, respectively, based on a false discovery rate multiple correction method. The regions harboring all, except three, of the QTL identified from the field and greenhouse studies overlap with positions of previously reported QTL. Further work should aim at validating the identified QTL using proper germplasm and populations to enhance their utility in marker assisted breeding. |