Effect of Pre-Sowing γ-Irradiation of sea buckthorn Seeds on the Content and Fatty Acid Composition of Total Lipids in the Seeds of the First Plant Generation

Absolute content and FA-composition of sea buckthorn (Hippophae rhamnoides L.) seed lipids were studied. The seeds of cvs. Vitaminnaya and Zyryanka belonging to the Siberian climatype and also the seeds of the first generation (M(1)) plants grown from the seeds subjected to pre-sowing. gamma-irradiation ((60)Co) at the doses of 50 and 100 Gy (cv. Vitaminnaya) and 100, 250, and 500 Gy (cv. Zyryanka) were used in analyses. In all treatments, irradiation resulted in the reduced seed weight in M(1) plants, which was sharper in cv. Vitaminnaya. In contrast, oil content declined strongly in cv. Zyryanka seeds, especially after irradiation with 500 Gy, whereas this index remained almost unchanged in cv. Vitaminnaya. Control and treated plants were close by their FA qualitative composition and by the total content of unsaturated FAs (88-90%). Pre-sowing seed irradiation resulted in the rise of the unsaturation index of lipids and linolenic acid concentration; at lower irradiation doses, this rise was more pronounced. With the increase of irradiation dose, the content of linolenic acid reduced in both cultivars, whereas the content of linoleic acid increased. As distinct from cv. Vitaminnaya, in cv. Zyryanka irradiation increased the content of linoleate and reduction in the level of oleate. The conclusion is that pre-sowing gamma-irradiation of sea buckthorn seeds could affect substantially on the basic quantitative indices characterizing seeds of M(1) plants. The range and direction of induced changes depend on both the dose of irradiation and cultivar genotype.