Genotypic Variation in Plant Growth and Physiological Response to Salt Stress in Grapevine

摘要

Soil salinity is one of the major stresses that severely limit the growth and production of grapes (Vitis vinifera L.) especially in the arid and semi-arid regions. Grapes are moderately sensitive to salinity and variation in response to salinity is shown among different grape varieties. To evaluate the effects of NaCl concentrations (0, 40, 80 and 120 mM) on the physiological and morphological responses of four Iranian grape cultivars, this research was carried out on potted vines under greenhouse conditions. Results showed that increase in NaCl concentration caused a significant reduction in length, diameter and dry weight of the root and shoot as well as leaf area. The highest and the lowest net photosynthesis reductions were recorded in the cultivars Askari (93%) and Rasha (80%), respectively. Salinity progressively reduced transpiration rate and stomatal conductivity in all grape cultivars, except Sarghola. However, intercellular CO2 concentration was increased with salt treatment in all the tested cultivars except Rasha. Na uptake increased with increasing salinity in all cultivars, with the highest Na accumulation in Askari. Rasha showed the least salt injury symptoms in response to high salt concentration. The patterns of changes in leaf K and Ca concentrations from 0 to 120 mM NaCl were quite different among the cultivars. K content at 120 mM NaCl in all cultivars, except Sarghola, was higher than that of the control. Also, the change in the level of Ca was minimal, except in Askari where Ca content decreased drastically at 120 mM NaCl. Based on the overall results, Rasha and Sarghola showed a higher capacity to tolerate higher salinity compared with the other cultivars.