مجله تولید و فرآوری محصولات زراعی و باغی

Reduction of deleterious effects of salt stress using some plant bioregulators has been reported in different plant species. Salicylic acid (SA) has been considered as a signaling molecule and it is known to ameliorate the oxidative damage caused by environmental stresses such as salt stress. The present study was conducted to investigate the effects of SA on different growth characteristics, photosynthesis, and photosynthetic pigments content in two grapevine (Vitis vinifera L.) cultivars, Qarah Shani and Thompson Seedless under NaCl stress. Plants were treated with 5 levels of nutrient solution salinity consisting 0 (control) , 25, 50, 75 and 100 mM NaCl and 4 levels of foliar-applied SA consisting 0 (control), 100, , 200 and 300 mg/l. Results indicated that the highest concentration of NaCl (100 mM) decreased all the growth parameters and net photosynthetic rate. Content of total chlorophyll QarahShani cultivar was much greater than Thompson Seedless. Net photosynthetic rate and stomatal conductance decreased in response to salt stress, but Qarah Shani showed a smaller reduction in photosynthesis than Thompson Seedless. NaCl in nutrient solution decreased photosynthesis of Qarah Shani and Thompson Seedless as much as 1.97 and 3.94, however with SA spray at the rate of 300 mg/l under NaCl (100 mM) these reductions were1.91 and2.52, respectively. These findings suggest that ameliorative effects of SA (200 mg/l) on growth and photosynthesis of both cultivars were notable especially for Qarah Shani, and also SA could be used as a potential growth regulator to improve plant salinity stress resistance.