Wild perennial sunflower as a potential source of reduced palmitic and stearic fatty acids in sunflower oil

Abstract

The trend in healthier human diets is to decrease the consumption of the saturated fatty acids. Sunflower oil, which is fourth in production among edible vegetable oils in the world, contains 65 g kg-1 palmitic and 45 g kg-1 stearic acids, both saturated fatty acids. These levels are high compared with rapeseed (Brassica napus L) oil with 40 g kg1 palmitic and 20 g kg-1 stearic acids. A reduction of saturated fats in traditional sunflower oil would lead to a healthier edible oil. The objective of this preliminary study was to search the vast genetic diversity available from wild ancestors of cultivated sunflower for potential sources of reduced palmitic and stearic fatty acids. Achene oil of one population of wild H. giganteus L. (GIG-102) from INRA, Montpellier, France, had 47 g kg-1 palmitic acid and 18 g kg-1 stearic acid. The combined 65 g kg-1 palmitic and stearic acids is 40% lower than the present level of these fats in sunflower oil. The level of saturated fatty acids observed in the population remained low when plants were grown in the greenhouse under uniform conditions. In the greenhouse, palmitic acid averaged 48 g kg-1, while stearic acid averaged 16 g kg-1. This would indicate that palmitic and stearic acid concentrations are under genetic control with potential for incorporation into cultivated sunflower. Crossing this population with an inbred cultivated line produced F1 plants with an achene oil that averaged 39 g kg-1 palmitic and 26 g kg-1 stearic acid. The inbred cultivated parent averaged 55 g kg-1 palmitic and 51 g kg-1 stearic acid. F2 plants produced an achene oil that averaged 47 g kg-1 palmitic and 29 g kg-1 stearic acid, for a total of 76 g kg-1. When F1 plants were back-crossed to the cultivated inbred, BC1F1 plants produced an achene oil that averaged 47 g kg-1 palmitic and 28 g kg1 stearic acid for a total of 75 g kg-1. The inbred cultivated parent averaged 54 g kg-1 palmitic and 56 g kg-1 stearic acid, for a total of 110 g kg-1. Preliminary information indicate that palmitic and stearic fatty acids in sunflower oil can be reduced by introducing genes from a wild perennial progenitor into cultivated sunflower. Further research will be needed to determine the inheritance of these fatty acids. Other agro-nomic traits will also have to be monitored during the introgression of genes for reduced saturated fatty acids into cultivated sunflower.