Submitted to: International Symposium on Plant Lipids
Publication Type: Abstract Only
Publication Acceptance Date: March 25, 2002
Publication Date: N/A
Technical Abstract: Dietary saturated fat has become an important concern of consumers in recent years, as studies have indicated that high levels of saturated fat consumption are correlated with increased risk of coronary heart disease. The purpose of the present study was to screen the USDA-ARS sunflower germplasm accessions to determine the extent of diversity for saturated fat content in the seed oil, and then to develop sunflower lines in which reduced saturated fat content is stably inherited. The total saturated fat content of oil from current sunflower hybrids averages about 13%. To identify sunflower germplasm with reduced saturated fatty acid composition, a total of 884 cultivated sunflower accessions from the USDA-ARS North Central Regional Plant Introduction Station, Ames, Iowa, were screened for fatty acid composition by gas chromatography. PI 250542, a cultivar collected in Egypt and deposited into the USDA-ARS National Plant Germplasm System in 1958, was identified as an accession with reduced saturated fatty acid content. The fatty acid composition of 26 half-seeds of PI 250542 was determined, and the seeds with lowest saturated fatty acids were grown out in the greenhouse. Pollen from a single plant was used to pollinate nuclear male-sterile line HA 89, and the F1 seed was grown in the field and self-pollinated. After several generations of selection by half-seed analysis, two lines (RS1 and RS2) were developed with a stable, reduced saturated fatty acid trait. The total saturated fatty acid composition of both RS1 and RS2, including C16 to C24 fatty acids, was less than 7.7% when grown in the field during the summer of 2000. To determine heritability of the reduced saturated fatty acid trait, both RS1 and RS2 were pollinated by sunflower line HA 821. The resulting F1 seeds were reduced in saturated fatty acids, suggesting that the reduced saturated fatty acid trait was dominant.