Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 14, 2012
Publication Date: February 6, 2013
Citation: Asoro, F.G., Newell, M.A., Scott, M.P., Beavis, W.D., Jannink, J. 2013. Genomewide association study for beta-glucan content in North American elite oat. Crop Science. 53:542-553. Interpretive Summary: Beta glucans are found in oat grain and have well-documented health benefits, including reducing serum cholesterol levels and reducing the risk of coronary heart disease. Because of these benefits, it is desirable to produce oat varieties containing high levels of beta-glucan. The best way to do this is by breeding. The current breeding approach requires measurement of beta glucan content in many samples which is an expensive and time-consuming process. In this work, we determined the genetic location of genes controlling beta glucan content on oat. This information will enable breeders to use improved breeding methods to develop high beta glucan varieties. This will reduce the cost and speed development of high beta glucan oat varieties. The public will benefit as foods with increased beta glucan content are developed from these high beta glucan oat lines.
Technical Abstract: Genome wide-association studies (GWAS) can be a useful approach to detect quantitative trait loci (QTL) controlling complex traits in crop plants. Oat (Avena sativa L.) beta-glucan is a soluble dietary fiber and has been shown to have positive health benefits. We report a GWAS involving 446 elite oat breeding lines from North America genotyped with 1005 DArT markers and with phenotypic data from both historical and balanced two-year data. Association analyses accounting for pair-wise relationships and population structure were conducted using single marker tests and LASSO. Single marker tests yielded six and 15 significant markers for the historical and balanced data sets, respectively. The LASSO method selected 24 and 37 markers as the most important in explaining beta-glucan content for the historical and balanced data sets, respectively. Comparisons of genetic location showed that 15 of the markers in our study were found on the same linkage groups as QTL identified in previous studies. Four of the markers co-localized to within 4 cM of three previously detected QTL, suggesting concordance between QTL detected in our study and previous studies. Two of these significant markers were also adjacent to a beta-glucan candidate gene in the rice genome. Our findings suggest that GWAS can be used for QTL detection for the purpose of gene discovery and for marker-assisted selection to improve beta-glucan content in elite oat.