L. Rezazad Bari - Department of Horticultural Science, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Islamic Republic of Iran.
A. Ghanbari - Department of Horticultural Science, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Islamic Republic of Iran.
R. Darvishzadeh - Department of Plant Production and Genetics, Faculty of Agriculture and Natural Resources, Urmia University, Urmia, Islamic Republic of Iran.
M. Torabi Giglou - Department of Horticultural Science, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Islamic Republic of Iran.
H. Doulati Baneh - Horticultural Crops Department, Kurdistan Agriculture and Natural Resources Research and Education Centre, Sanandaj, Islamic Republic of Iran.

Soil salinity is one of the most important environmental constraints that reduce plant growth and productivity. This study aimed to investigate the effects of various NaCl concentrations on the physiological properties of grape cultivars. NaCl was added at three levels (۰, ۲۵, and ۵۰ mM) to Murashige and Skoog medium under in vitro conditions to assess various effects on ۲۱ grape cultivars. Effects of salinity stress were investigated on ascorbate peroxidase, catalase, and superoxide dismutase activities, as well as malondialdehyde, protein, proline, chlorophyll A and B contents, of all samples. The results showed that with an increase in salinity, the amount of antioxidant enzymes, proline content, and protein increased in cv. Rasha, suggesting that it was more tolerant than the other cultivars. Malondialdehyde and Electrolyte leakage accumulation also increased in all cultivars, but this increase was higher in salinity-sensitive cultivars, such as hybrids and wild cultivars than resistant cultivars. During salinity stress, chlorophyll content decreased, and the lowest decrease in chlorophyll content was recorded in cv. Rasha, compared to other cultivars. This research demonstrated that the resistance of cv. Rasha, H۶ and H۴ to salinity stress was due to its ability to adjust proline, protein content, and antioxidant enzymes.

Salinity stress, Vitis vinifera, Proline, Grape cv. Rasha..