Physiological characterization of rice under salinity stress during vegetative and reproductive stages

Abstract

Salinity is one of the major environmental factors limiting crop productivity. For this reason, a greenhouse experiment was conducted in Rasht, North of Iran during 2010 growing season to evaluate the salinity levels of irrigation water at different growth stages on the some physiological characterization of rice. Treatments were arranged in a randomized complete block design with two factors and three replications. Factor one included four levels of saline water (2, 4, 6, and 8 dS m -1 ); factor two consisted of four growth stages (tillering, panicle initiation, panicle emergence and ripening). The results of this work showed that effect of different salinity levels on the all yield components except percentage of filled grains per panicle was not significant. Increase in salinity levels decreased this component. Effect of different growth stages on total number of empty grains per panicles, percentage of filled grains per panicle, number of unfilled panicles and percentage of ratio of number of unfilled panicles to tillers was significant but effect of different saline water on length of unfilled panicle and number of spikelets per unfilled panicle was insignificant. Resistance of final growth stages, i.e. panicle emergence and ripening stages against salinity was more than primary growth stages, i.e. tillering and panicle initiation. Therefore, in irrigation with saline water the final growth stages were important and irrigation with saline water should be applied at final growth stages.