SODIUM CHLORIDE PRIMING IMPROVES SALINITY RESPONSE OF TOMATO AT SEEDLING STAGE

Abstract

We aimed to investigate whether sodium chloride seed priming and irrigation at seedling stage enhance response of 5-leaf stage tomato plants (Lycopersium esculentum Mill.) to high salt stress. Three experimental groups were as; non-primed seeds, seeds primed with 0.05M sodium chloride (NaCl), and seeds primed and irrigated with 0.05M NaCl starting from sowing to salt stress application. Sodium chloride solutions (0.1M, 0.2M, 0.4M, and 0.6M) were added to cups under pots in every 2 days for 10 days to treatment groups. Control groups were irrigated with distilled water at the same time intervals. At least two experimental setups contained at least four plants, and two samplings of leaf and root tissues were performed for analysis of each plant to evaluate changes in pigment and proline contents, lipid peroxidation and electrolyte leakage levels, and ascorbate peroxidase and catalase activity. Priming reduced mean germination time, and increased final germination percentage together with energy of germination. Increased root and hypocotyl lengths as well as increases in fresh weights supported enhanced seedling vigor. Considering growth and stress parameters such as chlorophyll content, chlorophyll to carotenoid ratios, and lipid peroxidation and electrolyte leakage were less affected in primed plants. Moreover, improvement of the accumulation of osmoregulating defense molecules, such as proline and anthocyanin, and of the inductions of the antioxidative enzyme system points out to higher adaptive response of these plants against deleterious effects of salt.