Physiological effects of high temperature treatments on leaves of olive cv. gemlik

Abstract

Temperature is one of the most important environmental factors for survival of plants. Each plant has an optimum temperature for development and growth. However, as in most plant species, olive tree may be subjected to different temperatures distinct from its ecological needs. This study was conducted to investigate the effects of high temperatures which are likely to be observed in the future due to global climate changes on olive cv. Gemlik leaves. For this purpose, one-year shoots of 25 yearold olive trees were obtained at the end of May and the leaves were subjected to high temperature treatments in water bath at 40, 45, 50, 55, 60 and 65°C with gradual increments every 3 hours. The leaves were then analyzed for cell membrane injury, lipid peroxidation, loss of turgidity, leaf relative water content and chlorophyll content. Results revealed that membrane damage and lipid peroxidation were increased significantly starting at 50 oC, while leaf relative water content and chlorophyll content decreased. Therefore, it can be concluded that high temperature stress affects the growth and development of olive tree by damaging cellular membranes in leaves, reducing water content and inhibiting photosynthesis particularly when the temperature is above 50 °C in May in northwest of Turkey.