Genetic Analysis of Quantitative Trait Loci for Groat Protein and Oil Content in Oat

Abstract

Groat protein and oil content are major quality traits in oat (Avena sativa L.). Information regarding the number, genomic location, and effect of quantitative trait loci (QTL) for protein and oil content, and epistasis between these QTL would facilitate the development of oat cultivars with desirable levels of the two traits. QTL for protein and oil content were mapped and characterized in an oat population consisting of 152 recombinant inbred lines from the cross of ‘Ogle’ (low)/MAM17‐5 (high). Groat protein and oil were measured for samples harvested from field hill plots across two years. Composite interval mapping was used for QTL analysis with a framework map consisting of 272 molecular markers. Seventeen and six regions were identified significantly (LOD score threshold of 3.5) associated with protein and oil, respectively. Significant additive × additive gene interactions were detected for both protein and oil. In particular, the interactions between nonparental alleles played an important role in conferring high oil for most progeny of the cross. The final models best for single years, due to either the main effect or the interaction, explained 29 to 42% and 42 to 52% of the total phenotypic variation for protein and oil content, respectively. The QTL on OM6 and OM19 for protein and the QTL on OM3 and OM6 for oil, which were consistently identified, could serve as starting points for more intense scrutiny of genomic regions controlling groat protein or oil content in oat.