Effects of NaCl stress on photosynthetic and physiological indexes of strawberry leaves with different leaf ages.

Taking strawberry variety "Hongjia" as the tested material,the effects of NaCl stress on the photosynthetic and physiological indexes of strawberry leaves with different leaf ages were studied.The results showed that the potential chlorophyll fluorescence Fv/Fo was sensitive to NaCl stress,and it decreased obviously in the functional leaves.Among the photopia chlorophyll fluorescence parameters,the actual photochemical efficiency of PSⅡ,photochemical quenching and photochemical rate of strawberry new leaves and old leaves under NaCl stress declined significantly.The salt stress could significantly reduce the net photosynthetic rate,stomatal conductance and transpiration rate of strawberry functional leaves,but could increase the MDA content and the activities of SOD and POD in the functional leaves of strawberry.