Breeding for specialty oil types in sunflower

Abstract

Oil quality in vegetable oils is a relative concept that depends on the enduse of the oil. Vegetable oils are intended for food applications (salads and cooking oils, margarines, shortenings, etc) and nonfood industrial applications (biodiesel, lubricants, surfactants, etc). Sunflower (Helianthus annuus L.) oil has been traditionally appreciated in the world oil market. However, new emerging markets are demanding changes in oil quality for both food and nonfood applications. Nutritional and functional properties determining oil quality are primarily determined by the fatty acid composition of oil and the total content and composition of natural antioxidants, especially tocopherols. During the last 30 years these components have been extensively modified in sunflower through conventional selection from naturally occurring variation and trough mutagenesis. As a result, together with the standard sunflower oil whose fatty acid profile is made up of 11% saturated fatty acids, 20% oleic acid, and 69% linoleic acid, there is currently available a vast diversity of other sunflower oil types, for example low saturated ( 25%), high stearic (>25%), high oleic (>85%), high linoleic (>75%) as well as a number of oils with intermediate levels and combinations among them. Similarly, the standard sunflower oil with 95% of the tocopherols in the alpha-tocopherol form has been modified to produce oils with high levels of betatocopherol (>75%), gamma-tocopherol (>95%), and delta-tocopherol (>65%). The novel fatty acid and tocopherol traits are in all cases governed by a reduced number of genes, which facilitates considerably their management in plant breeding programs aimed at developing cultivars with improved oil quality. .