| The fluorescence characteristics and active oxygen metabolism in leaves of Lycium barbarum seedlings were studied under NaCl stress. The results showed that the fluorescence parameters Fv/Fm, Fv/Fo and фPSII were decreased with the increase of NaCl concentration, but NPQ was increased under low NaCl concentration stress, then it was decreased with the increase of stress. The activities of protective enzymes SOD, POD and CAT showed increase to different extents with the increase of NaCl concentration and the prolonging of stress time, however, the O-2 production rate and H2O2 content were also increased. This illustrated that the active oxygen in leaves was not eliminated in time, causing the photosynthesis rate decreased and the photosynthesis structure injured. It was also shown that the Lycium barbarum seedlings possessed certain adaptability to low NaCl stress (0.3%) and short-term stress (4 d). |