Effect of Different Levels of Soil Moisture on the Morphological and Physiological Characteristics of Three Grape Cultivars (Vitis vinifera L.)



Drought tolerance of three own-rooted grape cultivars (Rashe, Ghezil Uzum and Red Sultanina) was evaluated at four different levels of soil moisture contents (40, 60, 80 and 100% field capacity through a factorial experiment based on a randomized complete block design with three replications for a duration of 3 months. Results revealed that, grape cultivars, levels of soil moisture and the interaction between them had significant effect on fruit's morphological and physiological parameters. However, leaf temperature did not differ significantly among cultivars. With decrease in soil moisture from field copacity (F.C.), shoot length, number of leaves per plant, leaf area, fresh weight of leaf, dry weight of shoot and root relative water content (RWC) as well as chlorophyll index were significantly decreased, while leaf temperature, proline content and soluble sugars were increased. All the evaluated parameters, except leaf temperature and soluble sugars, were higher in “Rashe” than in other cultivars, but the level of soluble sugars was higher in “Ghezil Uzum” compared with others. The highest leaf chlorophyll index were observed for 100, 80 and 60% of F.C. in “Rashe” while the lowest chlorophyll indexes being observed in “Ghezil Uzum” and “Red Sultaninia” for the treatment of 40% of F.C. In the 40% of F.C. treatment, leaf temperature of “Red Sultaninia”, proline content of “Rashe” and soluble sugars in “Ghezil Uzum” were higher in comparison with those of the others. Based on the obtained results, “Rashe” and “Red Sultaninia” cultivars, were respectively found as the most, and the least drought tolerant cultivars.