Genetic factors influencing high oleic acid content in Spanish market-type peanut cultivars

Increasing the ratio of oleic to linoleic acid (On) in peanut (Arachis hypogaea L.) significantly improves the nutritional and quality attributes of the crop. In currently grown cultivars, the O/L ratio ranges from 0.8 to 2.5. Variation in peanut for On ratio has been characterized, and the On ratio is digenically inherited at two loci designated as Ol(1), and Ol(2). Previous research has been conducted with Virginia-and runner-type peanut; however, there have been no reports regarding the inheritance and allele frequency at these loci in Spanish-type peanut. The objectives of this study were to determine if the inheritance of the high oleate trait in Spanish-type peanut is similar to that previously reported and to determine the allelic composition of Spanish-type peanut at Ol(1) and Ol(2). Six different Spanish-type peanut cultivars (low oleate) were hybridized with F435-2-2 (high oleate), F-2 and BC1F1 progenies were evaluated for the On ratio. Segregation patterns indicated that high oleic acid content is digenically inherited in Spanish-type peanut, but there seems to be more allelic variation both within and among these cultivars, In addition, variation within the high and low oleate ratio classes indicated that other factors may be involved in determining the precise On ratio.