Mapping quantitative trait loci (QTLs) underlying seed vitamin E content in soybean with main, epistatic and QTLxenvironment effects

Soybean (Glycine max (L.) Merr.) seed contains small amounts of tocopherol, a non-enzymatic antioxidant known as lipid-soluble vitamin E (VE). Dietary VE contributes to a decreased risk of chronic diseases in humans and has several beneficial effects on resistance to stress in plants, and increasing VE content is an important breeding goal for increasing the nutritional value of soybean. In this study, quantitative trait loci (QTLs) underlying VE content with main, epistatic and QTLxenvironment effects were identified in a population of F-5:6 recombinant inbred lines from a cross between Hefeng 25' (a low-VE cultivar) and OAC Bayfield' (a high-VE cultivar). A total of 18 QTLs were detected that showed additive main effects (a) and/or additivexenvironment interaction effects (ae) in different environments. Moreover, 19 epistatic pairs of QTLs were found to be associated with -tocopherol (-Toc), -tocopherol (-Toc), -tocopherol (-Toc) and total VE (TE) contents. The QTLs identified in multienvironments could provide more information about QTL by environment interactions and could be useful for the marker-assistant selection of soybean cultivars with high seed VE contents.