Oil concentration and fatty acid composition of Achenes of Helianthus species (Asteraceae) from Canada

The cultivated sunflower (Helianthus annuus) is one of the four most import ant annual crops in the world grown for its edible oil. Species of the genu s Helianthus served as the ancestral stock for the present cultivated sunfl ower. The wild relatives are a valuable genetic reservoir for improving the crop species. This study examined oil concentration and fatty acid composi tion in oil of two annual Helianthus species (31 populations) and four pere nnial species (32 populations) from the prairie provinces of Canada. The hi ghest average oil concentration was observed in annual H. petiolaris with 3 1.3%. Among the perennials, H. maximiliani Schrad. had the highest average oil concentration with 31.1%. Helianthus tuberosus L. had the highest avera ge palmitic (16:0) acid concentration with 8.0%, while the lowest value was observed ii? H. petiolaris with 4.0%. The highest average stearic (18:0) a cid concentration was found in H. annuus with 2.9%, while H. petiolaris had the loll,est with 2.3%. The highest average oleic acid (18:1) was observed in H. petiolaris (18.4%), and the highest linoleic (18:2) was observed in H, maximiliani (77.4%). The variability within the wild species appears to be sufficient Sor altering oil and fatty acid characteristics in cultivated sunflower.