Effect of sodium chloride mediated salt stress on seedling vigour and growth of okra (Abelmoschus esculentus L.) grown in hydroponics

Salinity is a major abiotic stressor that has been reported to affect 900 million hectares of cultivated land and induce agricultural loss of more than $25 million per year. Okra is a vital annual vegetable crop grown globally in 2.5 million hectares of land. Further, it is a crop sensitive to a variety of abiotic stresses including salt stress, making it important to reveal the effect of salt stress on the morphological and biochemical parameters of okra. In view of this, the present study was conducted from May 2023 to July 2024 at Lovely Professional University, Phagwara, Punjab, India to determine the effect of variable NaCl concentrations; 25, 50, 75 mM, on the morphological and biochemical aspects of okra in hydroponics. Results indicated that the salinity stress reduced the growth attributes including shoot length (15-49%), root length (24-61%) and fresh weight (19-61%) as compared to the control. The physiological attributes such as photosynthetic pigments (Chlorophyll a, 11-34%; Chlorophyll b, 15-38%; and Carotenoids, 8-29%), carbohydrates (25-45%), and total proteins (23-50%) content were also diminished by salinity stress. Moreover, the accumulation of enzymatic parameters, superoxide dismutase, catalase, and ascorbate peroxidase, and the non-enzymatic components including phenol and flavonoids triggered the antioxidant system in okra seedlings to regulate the salinity stress.