Evaluation of some physiological and biochemical characteristics of several promising grapevine cultivars under low irrigation conditions

One of the most important climate changes today is the decrease in precipitation. The present study was conducted to investigate the effect of drought stress on some physiological and biochemical characteristics of some promising grape cultivars. Experimental treatments included 5 Russian grape cultivars (Qazagiski Ramphi, Supran Bulgar, Muscat Yamtazini, Kishmish Hisrao, Besmiamphi Ramphi) and two Iranian cultivars (Chafteh and Soltan) and 3 drought levels (100 (control), 70 and 40% field capacity). A factorial completely randomized design with three replications was conducted in the greenhouse of Takestan Grape Research Station. After stress application, catalase, peroxidase, guaiacol peroxidase, ascorbic peroxidase, and hydrogen peroxidase enzymes activity, soluble sugar, total proteins, proline, chlorophyll and leaf relative water content, leakage rate and membrane stability index were measured. Reducing the amount of irrigation water to 70 and 40% of relative field capacity significantly improved the activity of peroxidase, ascorbic peroxidase, hydrogen peroxidase, and guiocol peroxidase activity, and soluble sugar and proline concentrations. Water shortage significantly reduced ion leakage, chlorophyll content, leaf relative water and the stability of grape leaf cell membrane. There were differences among different grape cultivars in response to stress. In general, Qazagiski Ramphi cultivar was more resistant to drought stress than other cultivars. Bidaneh Sefid and Besmiamphi Ramphi were the second and third cultivars in drought tolerance capacity, respectively.