关键词: 碱茅, 盐胁迫, Na⁺、K⁺选择性吸收(SA), Na⁺、K⁺选择性运输(ST)

Abstract: The plants of potted Puccinellia tenuoflora were stressed by treating with various gradient solutions of mixed salts.The main ingredient is sulphate.Changes in the selective ab sorption (SA)capacity of Na⁺, K⁺ from the soil by root system and in the selective transportation (ST) capacity of Na, K in different parts of the plant under saline conditions were studied, and changes in the distribution characteristics of Na⁺, K⁺, Ca²⁺ and Cl^- in different parts of the plant under saline conditions were also studied.The results showed that SA value of the plant in treat-ment-1 and treatment-2 conditions is slightly lower than that of the plant in CK, and that ST1 (root system; stem)value of the plant in the former two conditions is higher than that of the plant in CK; SA value of the plant in treatment-3 is almost half of that of the plant in CK, ST1 value of the plant in treatment-3 is also lower than that of the plant in treatment-1 and treatment 2.This suggests that within a certain extent of salintiy, effects of salt stress on the selective ab sorption capacity of the root system are weak, and the selective transportation capacity of the root system somewhat increases; but in higher salinity, the selective absorption capacity of the root system decreases greatly, and the selective trarisportation capacity of the root system somewhat decreases.The fact that ST₂(stem: leaf sheath)values are lowest in all the salinity conditions indi cates that stem has a very weak selective transportation capacity.With the increase in salt content of the soil, ST₃(leaf sheath: blade) value of the plant increases correspondingly, this shows that under salt stress the capacity of the leaf sheath limiting Na⁺ and promoting K⁺ transported ion to the blade increases gradually.

Key words: Puccnellia tenuiflora, salt stress, selective absorption (SA) of Na⁺ and K⁺, selective transportation (ST) of Na⁺ and K⁺