Effect of salicylic acid on the quality of edible oil and fatty acids composition in different regions of sunflower (Helianthus annuus L.) heads

To study the effect of salicylic acid (SA) on the amount and quality of oil in different regions of sunflower inflorescence, a factorial experiment was conducted based on randomized complete block design with 3 replications at the University of Mohaghegh Ardabili, Ardabil, Iran. Salicylic acid at concentrations of 0, 0.1, and 0.2 g L-1 were sprayed on whole plant at 3 stages (twice before flowering and a third time after flowering) and kernels were collected from different regions of capitulum (inner, middle, and outer layers). Samples were taken fifteen days after flowering with 5-day intervals and the amount of oil and four fatty acids (palmitic, stearic, oleic, and linoleic acids) were measured. Results showed that SA increased content of oil and unsaturated fatty acids but decreased the amount of saturated fatty acids and improved the quality of the kernels obtained from the mother plant. Linoleic acid content increased more than oleic acid by spraying of SA and the concentration of 0.2 g L-1 SA was more effective. Kernel position had significant effect on the oil content and fatty acids, so that from the periphery toward the center there was a reduction trend in the oil and saturated fatty acid content.