Monday, November 2, 2009
Convention Center, Exhibit Hall BC, Second Floor
Confederate Daisy, or Porter’s Golden-Eye, Helianthus porteri, formerly known as Viguiera porteri, is an annual sunflower that was recently transferred to the genus Helianthus. It occurs in and around granite outcroppings in the Piedmont regions of North and South Carolina, Alabama, and Georgia. Wild sunflower species offer the potential to improve the quality of sunflower oil, a key issue in sunflower breeding. High levels of linoleic fatty acid (>720 g/kg) in sunflower oil make it desirable for use in the production of margarines. The objective of the study was to evaluate achene oil of H. porteri for the composition of four major fatty acids: palmitic (16:0), stearic (18:0), oleic (18:1), and linoleic (18:2). Achenes from eight populations collected in Georgia and North Carolina were analyzed. Fatty acid composition was determined using a gas chromatograph on oil extracted from two 10-achene samples for each population converted to methyl esters using an organic catalyzed transesterification method. Oleic acid concentration averaged 65.2 g/kg, which is low compared to typical sunflower oil. This resulted from a high linoleic acid concentration. The 815 g/kg average linoleic concentration in H. porteri was the highest observed in any wild species, with one population having a concentration of 830 g/kg. Higher linoleic acid concentrations (>700 g/kg) are generally observed at northern latitudes, while lower values are observed at southern latitudes. Linoleic acid concentrations observed in this study were much higher than one would expect for populations grown in southern latitudes. The high linoleic acid concentration observed in H. porteri has the potential to improve the linoleic concentration in commercial sunflower oil. Further research will be needed to determine the inheritance of the linoleic fatty acid.