Effect of salt stress on some morphophysiological characters of two rice culitivars during different growth stages at greenhouse

In order to evaluate the effects of salt stress in different growth stages on morpho physiological traits in rice, a greenhouse experiments was conducted in three replications with using two rice cultivars, including Daylam and PSBRC88 as main plats, as well as three salinity levels including 0, 6 and 12 dS/m at vegetative growth, stem elongation and flowering as sub-plots in a split plot factorial based on RCBD. Salinity treatments were imposed for 20 days in nutrition solution at each stage. Results showed that total and leaf area as well as their dry weight, decreased with increasing salinity at different growth stages. K+ concentration with increasing salinity levels decreased while that of Na+ increased. The SPAD value, RWC, stomatal conductance and photosynthetic rate also declined. Reduction at flowering stage was more than vegetative growth and stem elongation stages. The maximum reduction in dry matter in any growth stage of growth, was observed at 12 dS m salinity level. Saline water with EC 12 dS/m, at the flowering stage reduced leaf area, total dry weight, photosynthetic rate and stomatal conductance by as much as 12, 25, 48 and 55 percent.