SEED FATTY ACID PROFILES: POTENTIAL RELATIONS BETWEEN SEED GERMINATION UNDER TEMPERATURE STRESS IN SELECTED VEGETABLE SPECIES

The study was undertaken to determine characterization of the fatty acid profile of pepper (Capsicum annuum L.), eggplant (Solanum melongena L.), radish (Raphanus sativus L.) and cabbage (Brassica oleracea var. capitata) seeds as well as relations between fatty acid profile and seed germination under temperature stress in controlled conditions. Germination tests were conducted using four replicates of 50 seeds from each species at low, optimum and high-temperatures (5, 10, 15, 20, 25 30, 35 and 40 C). Germination percentage of pepper, eggplant, radish and cabbage in last count ranged from 1.28 to 72.10, from 1.28 to 74.88, from 22.51 to 88.72 and from 1.28 to 74.94, respectively. Palmitic (C16:0), oleic (C18:1n-9) and linoleic,(C18:2n-6), acids were sequentially the highest in concentration followed by stearic acid (C18:0) at less than 5% and miristic, palmitoleic, margaric, arachidic, erucic, behenic and nervonic acids at an even lower content (<1%) in pepper and eggplant. Erucic acid (C22:1n-9) was the principal fatty acid followed by oleic, linoleic, gadoleic and behenic acids and miristic, palmitic, palmitoleic, arachidonic and stearic acids at a lower content between <1% and 5% in radish and cabbage seeds. The simple correlation coefficients and stepwise multiple regression analysis showed that the low or high amount of fatty acids in tested species such as palmitic (C16:0), palmitoleic (C16:1n-7), margaric (C17:0), stearic (C18:0), oleic (C18:1n-9), linoleic (C18:2n-6), arachidic (C20:0), gadoleic (C20: 1n-9), arachidonic (C20:4n-6), behenic (C22:0), MUFA, n-6 PUPA and total oil might play a major role in seed germination under low and high temperatures.