| In order to explore the effectiveness of photosynthetic characteristics as evaluation index for salt tolerance,
the chlorophyll fluorescence kinetics parameters of maximal fluorescence (Fm), variable fluorescence (Fv), minimal
fluorescence (Fo), maximal photochemical efficiency of PS Ⅱ(Fv/Fm), photochemical efficiency of PS Ⅱ(ØPSII), non -
photochemical quenching(NPQ) of four kinds of trees(Ulmus pumila, Lycium dasystemum, Celastrus orbiculatus and Syringa
microphylla) differing in tolerance to salt stress were determined. The results showed that saline and alkaline stress had
negative impact on the function of PSⅡin the four trees. With the increase of stress intensity, Fm , Fv , Fv / Fm、ØPSⅡof the four seedlings deceased gradually, Fo and NPQ, however, expressed increasing trends. The results suggested that Fo, Fv and Fv/Fm could be used as effective index for salt tolerance assessment of woody plants with different life forms, while Fm ,NPQ and ØPSII could not. |
