No abstract

We investigated variability in the response of oil fatty acid composition to temperature among high stearic and high stearic-high oleic sunflower (Helianthus annuus L.) genotypes. Two experiments were conducted with high stearic (including the CAS-3 mutation) and high stearic-high oleic inbred lines (including both the CAS-3 and the high oleic Soldatov mutations). Plants were cultivated in pots with soil, irrigated, and fertilised. Plants were exposed to different day/night temperatures during grain filling: 16/16°C, 26/16°C, 26/26°C, and 32/26°C. Oil fatty acid composition was determined by gas–liquid chromatography in seeds harvested after physiological maturity. Higher temperature during grain filling increased palmitic and oleic acid percentages and reduced stearic and linoleic acid percentages, suggesting some modifications on enzymatic activities. When the high oleic mutation was included, the variation in stearic and oleic acid percentages in response to temperature was reduced but not the variation in palmitic acid concentration. Variations in fatty acid composition in high stearic genotypes were mainly associated with night temperature as reported previously for traditional and high oleic hybrids. Knowing the effect of temperature on oil fatty acid composition in traditional and mutated genotypes is useful for selecting the environment in which to produce grains with the desired oil quality.

The NM1 mutation is the best option to develop ultra-high oleic sunflower oil that is stable across environments and genetic backgrounds, making its agronomical production more efficient and predictable. © 2018 Society of Chemical Industry.

No abstract

BACKGROUND This study characterized the influence of temperature during grain filling on the saturated fatty acid distribution in triacylglycerol molecules from high stearic sunflower lines with different genetic backgrounds. Two growth chamber experiments were conducted with day/night temperatures of 16/16, 26/16, 26/26 and 32/26 °C. RESULTS In all genotypes, independently of the genetic background, higher temperatures increased palmitic and oleic acid and reduced linoleic acid concentrations. Increasing night temperature produced an increase in saturated‐unsaturated‐saturated species, indicating a more symmetrical distribution of saturated fatty acids. The solid fat index was more affected by temperature during grain filling in lines with high linoleic than high oleic background. Higher variations in symmetry among night temperatures were observed in lines with high oleic background, which are more stable in fatty acid composition. CONCLUSION The effect of temperature on triacylglycerol composition is not completely explained by its effect on fatty acid composition. Thus night temperature affects oil properties via its effects on fatty acid synthesis and on the distribution of fatty acids in the triacylglycerol molecules. © 2016 Society of Chemical Industry