The production of active oxygen in the leaves of sugarcane were accelerated and their scavengering ability weakened when they were subjected to water stress. With water stress intensifying, the malondialdehyde (MDA) content and plasma membrane permeability were raised depending on the genotypes. The decrease of 2,6 dichlorophenol indophenol photoreductive activity, Fv/Fm, Fv/Fo ratio and Fds/Fms values of chloroplast isolated from sugarcane leaves suggested that PSⅡ activity, the primary...