Effects of Salt Stress on the Contents of Proline in Different Varieties of Lonicera japonica Thunb.

[Objective] To study the effects of salt stress on the contents of proline in the leaves of different varieties of Lonicera japonica Thunb.. [Method] The seedlings of Lonicera japonica Thunb. were treated with different concentrations of NaCl solution (0,100,200,400 and 600 mmol/L), and the proline content can be used as indicator for evaluating the salt tolerance of Lonicera japonica Thunb..[Result] After short treatment, the content of proline in the leaves of treelike Lonicera japonica Thunb. increased dramatically with the concentration of NaCl increased; although there were no significant difference among the vinelike Lonicera japonica Thunb. groups, the content of proline in the leaves of vinelike Lonicera japonica Thunb. increased dramatically with the concentration of NaCl increased as time went by. The contents of proline in treelike and vinelike Lonicera japonica Thunb. achieved the highest level when the concentration of NaCl was 400 mmol/L. [Conclusion] The proline in the leaves of treelike Lonicera japonica Thunb.was more sensitive to salt stress and showed stronger osmotic regulation ability.