Genetic analysis of the high oleic acid content in cultivated sunflower (Helianthus annuus L.)

Summary Sunflower lines breeding true for very high oleic acid content in their oil (average levels higher than 85%) were crossed with standard sunflower lines with mean oleic acid levels of 30%. Analysis of the oil of F₁ seeds indicated dominance for high oleic levels and control of the genotype of the embryo. Segregating generations were obtained selfing heterozygous high oleic BC_nF₁ plants from several generations of a backcrossing program to incorporate the high oleic character to standard inbred lines and testcrossing these plants to low oleic material. Analysis of F₂ and testcrossed seeds showed three kind of segregations, in both F₂ and testcrossed populations, with different proportions of low, intermediate and high oleic types. Genetic analysis of these data supported the hypothesis, that the high oleic character is controlled by three dominant complementary genes OL₁, OL₂ and OL₃. Additional data showing F₁ seeds with intermediate oleic content and segregations for high oleic in progenies of intermediate types, suggest the presence of major factors modifying high oleic acid content.