The Effect of High and Low Temperature Stress on Growth, Photosynthesis and Antioxidant Activity in Vegetative Growth Stage of Tomato

The aim of this was to investigate the effect of high and low temperature stress on growth, photosynthesis and antioxidant changes in vegetative growth stage of tomato. Tomato plants which were grown in hydroponics system exposed to temperature stress at 40 ºC and 10 ºC compared with plants grown in the greenhouse at optimum temperature of 25±2 as control. All plants were transfer to optimum condition in the greenhouse after stress treatments and growth parameters were measured after 10 days. The results of the comparison between these three temperatures showed that the highest fresh weight of shoot was observed at control treatment. In high temperature stress conditions observed 56.7% decrease fresh weight compared to control treatment and in low temperature stress conditions observed 65.3 decrease. Similarly, fresh weight of root was highest in control treatment and heat stress 45% and low temperature stress 64.6% showed decrease compared to optimum temperature conditions. Root volume was reduced by temperature stress significantly and photosynthesis rate was the highest in control treatment and lowest under high temperature stress. In general, it can be stated that temperature stress in this study affected growth and photosynthetic traits more than antioxidant traits.