Genetic mapping of loci involved in oil tocopherol composition control in Russian sunflower (Helianthus annuus L.) lines

Tocopherols are antioxidants that preserve oil lipids against oxidation and serve as a natural source of vitamin E in the human diet. Compared with other major oilseeds like rapeseed and soybean, sunflower (Helianthus annuus L.) exhibits low phenotypic diversity of tocopherol composition, both in wild and cultivated accessions from germplasm collections. Two major mutations that alter tocopherol composition were identified in genetic collections, and several studies suggested additional loci controlling tocopherol composition, with their expression possibly depending on the genetic background. In the present study, we performed QTL mapping of tocopherol composition in two independent F2 crosses between lines with contrasting tocopherol composition from the Pustovoit All-Russia Research Institute of Oil Crops (VNIIMK) collection. We used genotyping-bysequencing (GBS) to construct single nucleotide polymorphism-based genetic maps, and performed QTL mapping using quantitative and qualitative encoding for phenotypic traits. Our results support the notion that the tocopherol composition in the assessed crosses is controlled by two loci. We additionally selected and validated two single nucleotide polymorphism markers for each cross which could be used for marker-assisted selection.