Gamma radiation effects on fattly acid composition of lipids in cotton leaves

The mechanism of high irradiation dose (30 kR) effect on the lipid fatty acid composition of cotton leaves was studied in the ontogenesis. The experiment was carried out in vegetation vials (capacity 25 kg, humidity level - 65% of full water capacity). Before seeding, each vial was fertilized with 5g P2O5, 3g K2O and 5gN as an auxillary nutrition during vegetation. The test vials also contained 0.4 - 0.5 g CaO per kg of soil. A portion of irradiated seeds was soaked in 1.5% solution of CaO and Ca(NO3)2 before seeding. The cotton seeds were gamma-irradiated at 50 R/sec in the Institute of Nuclear Physics, Usbec SSR Academy of Sciences. The fatty acid composition of mature leaf lipids determined by gas-liquid chromatography proved to change in the blooming phase. Leaves of irradiated plants contained traces of myristic acid, higher levels of palmitic, palmitoleinic and strearinic acids and lower levels of oleinic and linoleic acids. Lower content of fatty acids with long carbon chains seemed to handicap the renewal of membranes and their components, especially in mitochondria. When irradiated seeds were soaked in calcium salt solution and CaO is added to the soil, the amount of unsaturated long chain fatty acids increased. The fact probably promotes the membrane renewal in irradiated plants