Response of Main Osmotic Adjustment Substances to NaCl Stress Accumulation in Atriplex canescens

In this study,Atriplex canescens(Pursh) Nutt.plants were cultivated in sand-pots and irrigated with NaCl water so as to research the response of main osmotic adjustment substances to NaCl concentration and stress time for 1,5,10,20,40 and 60 days respectively.The result are as follows:(1) The effects of stress time on proline,K+,Na+ and Cl-contents and K+/Na+ ratio in A.canescens leaves were extremely significant.The proline and Na+ contents in A.canescens leaves were increased with the stress time,but the K+ content and K+/Na+ ratio was decreased.The change of Cl-content was complicated.Proline and Na+ contents were slightly increased when the stress time was shorter than 40 days but increased significantly when the stress time was longer than 40 days;(2) The effects of NaCl concentration on the proline,K+,Na+ and Cl-contents and K+/Na+ ratio in A.canescens leaves were extremely significant.The proline and Na+ contents were increased with increasing NaCl concentration,but K+ content and K+/Na+ ratio was decreased.Under high NaCl concentration,the Na+ and proline contents were significantly increased,but the K+ content and K+/Na+ ratio was significantly decreased;(3) The ion transportation of A.canescens was selectable.Under salt stress,K+ was selected to transport from roots to stems,but Na+ was still remained in roots;Na+ was selected to transport from stems to leaves,the transportation of K+ to leaves was restricted,and K+ was transported from roots to stems;the K+/Na+ ratio in different vegetative organs was in an order of stem leaf root,and the ratio was decreased with increasing NaCl concentration.In conclusion,the effects of NaCl concentration on proline,K+ and Na+ contents and K+/Na+ ratio were increased with the NaCl stress time,and the interaction between NaCl concentration and stress time affected significantly the proline,Na+ anad Cl-contents in A.canescens leaves.Therefore,the time scale and interaction between NaCl concentration and stress time should be considered in further research in the future.