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

Increasing the ratio of oleic to linoleic acid (On) in peanut (Arachis hypo gaea L.) significantly improves the nutritional and quality attributes of t he 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). Previ ous research has been conducted with Virginia-and runner-type peanut; howev er, there have been no reports regarding the inheritance and allele frequen cy 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 pe anut is similar to that previously reported and to determine the allelic co mposition 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 olea te), F-2 and BC1F1 progenies were evaluated for the On ratio. Segregation p atterns indicated that high oleic acid content is digenically inherited in Spanish-type peanut, but there seems to be more allelic variation both with in and among these cultivars, In addition, variation within the high and lo w oleate ratio classes indicated that other factors may be involved in dete rmining the precise On ratio.