Variation in Carbohydrate Accumulation in Two Cultivars of Mustard and its Association with Salt Tolerance

Among various environmental stresses, soil salinity is one of the most severe stress factors that may impair crop productivity. Increased salinization of arable land is expected to have devastating global effects resulting 50% land loss by the year 2050. The physiological and biochemical responses of two different mustard cultivars (cv. Varuna and cv. SS2) to salt stress were studied under green house conditions. The plants were grown in pots and were treated for 7 days with NaCl starting at the appearance of the first trifoliate leaf unfolded. It was established that the applied dose of NaCl caused stress in the young mustard plants, which found expression in the suppression of growth and photosynthesis activity. The applied NaCl caused stronger inhibition in both the cultivars but the effect was more pronounced on cv. SS2 than cv. Varuna. The amount of carbohydrate in the tissues of the salt-treated plants increased, while the cell water potential was reduced. Adaptation of plants to salinity is associated with osmoregulation adjustment. Variation in carbohydrate accumulation is of particular importance because of their direct relationship with physiological processes as photosynthesis, translocation and respiration. Further, accumulation of carbohydrate under salinity stress is an osmotic adjustment that helps plants to survive under stress and greater accumulation in Varuna and least in SS2 helps in categorizing Varuna as a tolerant cultivar.