Seed halopriming outdo hydropriming in enhancing seedling vigor and osmotic stress tolerance potential of rice varieties

Abstract

Seed priming improves the seed performance and also helps the seedlings to alleviate the detrimental effects of various stresses. Seed priming is believed to bring about some biochemical changes in the metabolism within the seed, which ultimately favors germination and the further growth stages of the seedlings even under stressed conditions. The present investigation was carried out to study the effect of hydropriming and halopriming in three rice varieties (Neeraja, Vaisakh, and Vytilla 6), with varied abiotic stress tolerance potential under NaCl and PEG stress. In general, the application of both stresses, NaCl and PEG induced retardation of growth and metabolism of the seedlings. However, seed priming treatments could reduce the extent of decrease in these biological attributes. Both hydro- and halopriming resulted in the enhancement of protein, carbohydrate, and photosynthetic pigment content, modulated antioxidant enzyme activities, reduced the lipid peroxidation of biomembranes, and enhanced the photochemistry and mitochondrial activities in rice seedlings subjected to NaCl and PEG stress as compared to non-primed ones. According to the various morphological, physiological, and biochemical characteristics studied in the rice seedlings raised from primed and non-primed seeds, we confirmed that both hydropriming and halopriming had a positive influence on stimulating metabolism in rice seeds, which ultimately resulted in improved seedling vigor and tolerance under NaCl and PEG stress. Halopriming was found to be more efficient than hydropriming in enhancing the seedling vigor, overall growth, and stress tolerance potential of rice varieties.