PERFORMANCE OF NEAR-ISOGENIC HIGH AND LOW OLEIC-ACID HYBRIDS OF SUNFLOWER

The development of hybrids with high levels of monounsaturated oleic acid is an important goal among sunflower (Helianthus annuus L.) breeders. The objective of this study was to determine the association of high oleic alleles with agronomic and chemical characters of sunflower. Two cytoplasmic male sterile and two restorer parental lines averaging 890 g kg(-1) oleic acid and their isogenic counterparts with 230 g kg(-1) oleic acid were crossed to obtain four high oleic and four low oleic acid near-isogenic hybrids. The pairs of isogenic hybrids were evaluated for agronomic performance in a replicated test at several locations differing widely in temperature and water availability during seed formation. High oleic acid hybrids produced significantly greater seed yield, oil content, and above-ground biomass than low oleic acid hybrids. For the other evaluated characters, high oleic acid hybrids were earlier and less self-compatible than their isogenic counterparts with low oleic acid forms, although there were differences between environments and genetic backgrounds. The high oleic acid hybrids averaged 626 g kg(-1) higher oleic acid content than low oleic hybrids. This difference was lower for open-pollinated seed although high oleic hybrids maintained oleic acid levels near 775 g kg(-1) under open pollination. The high oleic OL allele appears to have a positive influence on yield and oil content and a negative effect on self-compatibility; but it depends somewhat on the genetic background into which they are introduced.