Evaluation of some physiological and morphological responses of four Iranian grapevine (Vitis vinifera L.) cultivars to drought stress under in vitro conditions

Water stress is one of the most important abiotic limiting factors that restricts growth, development and productivity of horticulrural crops. In vitro methods have been successfully used for evaluating water deficit stress in plants. In this regards, responses of four Iranian grapevine genotypes to drought stress induced by polyethylene glycol 6000 at -5, -5.24, -5.65, -6.24 and -7 bar were studied in Murashige and Skoog (MS) medium. Results indicated that drought stress reduced shoot fresh weight, leaf area, shoot length and leaf relative water content. Water deficit stress also caused significant increase in proline and malondialdehyde content, and activity of catalase antioxidant enzyme,. It seems that among studied genotypes, ‘Shahani’ with a greater capability to produce proline and antioxidant enzymes was more tolerant to drought stress and ‘Keshmeshi Ghermez Ghazvin’ and ‘Yaghuti Sefid’ genotypes were more susceptible and eventually ‘Asgari’genotype performed semi tolerance to water deficit stress.