Leaf water potential, photosynthetic pigments and compatible solutes alterations in four grape cultivars under salinity

Abstract

A hydroponic culture experiment was conducted to investigate the effects of different concentrations (0, 25, 50 and 100 mM) NaCl on own-rooted table grape (Vitis vinifera L.) cultivars (red 'Rishbaba', red 'Sahebi', 'Dastarchin' and red 'Sultana') under greenhouse conditions. Cultivars were evaluated for growth analysis leaf area, leaf water potential and the chlorophyll a, b and carotenoid contents in relation to proline and soluble sugars accumulation. Salinity treatments caused a growth reduction (P ≤ 0.05) in all the cultivars. Also leaf water potential and chlorophyll a, b contents decreased whereas carotenoid, proline and soluble sugars increased with increasing NaCl concentration. 'Dastarchin' and red 'Sultana' showed the salt- sensitivity, the highest loss of growth, leaf water potential and chlorophyll content and the lowest accumulation of carotenoids, proline and soluble sugars. Also salt stress significantly (P < 0.001) increased the rate of lipid peroxidation in the all cultivars particularly in 'Dastarchin' and red 'Sultana'. The increase in malondialdehyde content indicated that salinity induced oxidative stress. There was a significant negative correlation between leaf water potential and NaCl concentrations (r2: -0.781, p < 0.001). A positive correlation was also found between lamina proline contents and NaCl concentrations (r2: +0.964, p < 0.001) for all salinity treatments. Considering overall results red 'Rishbaba' and red 'Sahebi' showed higher capacity to tolerate salinity when compared to 'Dastarchin' and red 'Sultana'.