XVI International Botanical Congess
Superoxide dismutases (SOD) are metal-containing enzymes that catalyze the dismutation of superoxide radicals to oxygen and hydrogen peroxide. The effects of water stress on growth, water status and SOD activities in four tomato cultivars were examined. As expected, growth of drought-tolerant TM 0126 (TM) and VF-134-1-2 (VF) was better than that of drought-sensitive Kyokko (KK) and Ratan (RT) under water stress conditio n s . Leaf water potential was decreased by the treatment in all the cultivars, but the reduction was more rapid and pronounced in KK and RT than VF and TM. SOD activities were increased by water stress in all the cultivars . Increase of SOD activities by water stress was more rapid and pronounced in TM and VF than in KK and RT. Protein concentration was decreased by the water stress treatments in all the cultivars. In KK and RT, more rapid reduction was observed than in TM and VF. The regression analysis suggests possibility to use SOD activities as a criterion for tomato drought tolerance.