Grapevine is a Key Plant Utilizable against Extreme Conditions and Water Shortage Crisis in South of Iran

In recent years, the water shortage is a major, economic and social problems of Iran especially in Fars province. Development of horticultural crops with low water requirement feature can be used as a policy to reduce the water loss from limited water resources in Fars province (South of Iran). Grapevine with a low water requirement (about 5000 m3/ha.) in comparison to citrus plants is one of the most important horticultural crops can be used to overcome this problem. Determining the commercial grapevine cultivars adapted to warm climate condition is considered as a major factor to successful development of viticulture in this region. The aim of thisresearch was to determine Physico-biochemical and physiological responses of six grapevine cultivars (Askari, Monagha, Rotabi, Flame Seedless, Perlette and Yaghooti) to warm climate conditions of Ghir-o-Karzin region in south of Iran for two years. Leaf chlorophyll content, relative water content (RWC), electrolyte leakage (EL), Fv/Fm, carotenoid and leaf gas exchange parameters were measured. Results showed that gas exchange responses of grapes to high temperature stress varied with the cultivar and it was cultivar dependent. Flame Seedless had a relatively desirable photosynthetic rate and it was a heat- tolerant cultivar. Photosynthetic rate of Perlette and Rotabi was less than Flame Seedless. Therefore, they were moderately- heat- tolerant cultivars. Askari and Monagha were heat-sensitive cultivars compared to Flame Seedless and Rotabi. Photosynthetic rate in Yagooti was more than Askari and Monagha and less than other cultivars. Heat tolerant cultivar in this study (Flame Seedless) had highest levels of photosynthetic rate (A), stomatal conductance (gs), transpiration rate (E), leaf chlorophyll content (total chlorophyll,chlorophyll a and chlorophyll b), carotenoid and Fv/Fm