The relationship between the accumulation of salt ions and be taine，and the photosynthesis in leaves of Lycium barbarum L．under salt stress

Effects of NaCl on concentrations of salt ions and glycinebetaine and photosynthesis of salt-tolerance Lycium barbarum L．are determined．The results show that leaf burn sysnptoms are very serious under NaCl stress of 9～12g／kg concentration，and slight under its concentration of 0．8～6egkg．With the increasing of NaCI concentration and the prolongation of days of treatment，the contents of Na and C1-are accum ulated gradually．As to the NaCl concentration，the rate of photosynthesis of Lycium barbarum L．gradually decreases．When the concentration of NaCl is 0．8～6g／kg，the photosynthesis of Lycium barbarum L．1eaf is decreased，which is caused mainly by the decrease of stomatal conductance．On the contrary，when the concentration of NaCl is more than 6g／kg，the photosynthesis is decreased yet．The main cause is that the photosynthetic enzyme is damaged by surplus Na and Cl-accumulated in the Lycium barbarurn L．1ea f，therefore．the non-stomatal limitation becomes the main factor，decreasing seriously the photosynthesis and PS 11 photochemica1 efficiency．Accumulations of Na and C1-show a trend from quick to slow，while betaine is accumulated excessively．The accumulation of betaine is also contributed to the salt resistance of Lycium barbarum L．