Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 10, 2007
Publication Date: October 10, 2007
Citation: Seiler, G.J., Gulya, T.J., Marek, L.F. 2007. Wild perennial Helianthus pumilus as a potential source for improved oil content and quality in cultivated sunflower. Association for the Advancement of Industrial Crops, October 7-10, 2007, Portland, Maine. Abstract OC-07. p. 52. Technical Abstract: The genus Helianthus consists of 51 species and 19 subspecies with 14 annual and 37 perennial species. The narrow genetic base of cultivated sunflower has been broadened by the infusion of genes from the wild species, which have provided a continued source of desirable agronomic traits. There has been an increased interest in using wild species in breeding programs, but there have been concerns about the introgression of low oil content and quality from the wild species. Helianthus pumilus (Dwarf sunflower) is a perennial species with potential genes for oil improvement based on its xerophytic habitat. Unfortunately, due to the demand for achenes of this species and the difficulties of regenerating achenes from the original populations, few achenes have been available for research for almost 20 years. The objective of the study was to undertake an exploration to Colorado and Wyoming, USA to collect achenes from the entire distributional range of the species and assess the potential of the populations for improving oil content and quality in cultivated sunflower. The sunflower exploration took place from August 7 to August 19, 2005 and covered 5150 kilometers in Colorado and Wyoming. Heads were collected from 10 to 100 plants within each population and were bulked into a single sample. For each population, a composite sample of 10 randomly sampled achenes was analyzed for fatty acids composition using organic base-catalyzed transesterification of fatty acid methyl esters and capillary gas chromatography. Oil content was determined on a 2-ml achene sample using nuclear magnetic resonance (NMR). The achene samples were deposited at the USDA-ARS, NPGS, North Central Regional Plant Introduction Station, Ames, Iowa, where they are maintained and distributed. Voucher specimens are maintained at the USDA-ARS wild sunflower species herbarium at Fargo, North Dakota. It had been 20 to 30 years since six known locations of this species were last visited. Achenes of 47 additional populations were collected and placed in the wild sunflower germplasm collection. The exploration was successful in collecting representative populations from the entire distributional range. The H. pumilus populations had an average oil content of 254 g/kg, which is considerably lower than cultivated sunflower which average 470 g/kg. The highest oil content of an H. pumilus population was 294 g/kg, 30% higher than previously reported. The linoleic acid concentration approached 750 g/kg, much higher than the 540 g/kg expected from a semi-arid environment. The combined saturated palmitic and stearic fatty acids in H. pumilus averaged 102 g/kg, about equal to cultivated sunflower oil average of 110 g/kg. The higher concentrations of linoleic acid in H. pumilus could be a potential source of genes for increasing linoleic acid concentration in traditional sunflower oil. The low oil content of this species can be increased by backcrossing to a high oil cultivar. Further research will be needed to determine the inheritance of the fatty acids and oil content traits.