Lipid Composition in Fast and Slow Germinating Sunflower (helianthus Annuus L.) Seeds

The physiochemical characteristics and lipid composition in fast and slow germinating sunflower (Helianthus annuus L.) seeds were studied. The quantity of phospholipids, glycolipids and sterols in cotyledons and embryonic axes in fast germinating seeds (FG embryo emerged within 24 h after sowing) increased progressively between the 1st 6th days after sowing (DAS) compared with the slow growing seeds (SG embryo emerged after the 4th DAS). The fatty acid composition in cotyledons of FG seeds showed increased levels of palmitic and oleic acids 6 and 8 DAS, while a decline in palmitic and stearic acids as well as accumulation of oleic and linoleic acids were observed in SG seeds. However, higher content of linolenic acid was found in the embryonic axes of FG seeds compared with SG seeds 6 and 8 DAS. The FG seeds located in the peripheral whorls of the inflorescence, with high quantity of storage lipids, contributed to the enhanced rate of germination compared with SG seeds located in the central whorls.