Physiological responses of two Turkish rice (Oryza sativa L.) varieties to salinity

Effects of salinity (60 mM NaCl) on 2 Turkish rice varieties (Kıral and Yavuz) were studied in comparison to 2 international check varieties (IR4630-22-2 tolerant and IR31785-58-1-2-3-3 susceptible) in 2 hydroponic and 1 outdoor soil-based pot experiments. Partitioning of dry matter, leaf chlorophyll concentration, K^+ and Na^+ uptake, and proline accumulation in the leaves were investigated under both control and salt stress conditions. Dry matter accumulation decreased with salt stress in all varieties, with the decreases being more pronounced in IR31785 and Kıral. The results showed that the varieties tested expressed different adaptation mechanisms under salt stress; however, the increase of leaf proline accumulation was a general indicator for responses to salt stress in all cultivars.