NaCl、Na_2SO_4和Na_2CO_3胁迫对小麦叶片自由基含量及质膜透性的比较研究

分别用浓度为２５ｍｍｏｌ／Ｌ、５０ｍｍｏｌ／Ｌ、１００ｍｍｏｌ／Ｌ和２００ｍｍｏｌ／Ｌ的ＮａＣｌ、Ｎａ２ＳＯ４和Ｎａ２ＣＯ３的营养液培养小麦４ｄ，较之不含盐的营养液，其自由基含量上升，产生速率增加，叶片质膜透性增加。不同盐的影响也不同，在低浓度时，ＮａＣｌ的影响大于Ｎａ２ＳＯ４，高浓度时，ＮａＣｌ影响小于Ｎａ２ＳＯ４，Ｎａ２ＣＯ３的影响最为显著。实验结果也表现出小麦叶片自由基含量和质膜透性呈现较好的相关性。因此可认为，盐胁迫促使自由基含量增加，自由基通过过氧化作用影响质膜透性，从而影响植物的生长。

COMPARATIVE STUDY ON CONTENT OF FREE RADICAL AND MEMBRANE LEAKAGE IN WHEAT LEAVES UNDER SALT STRESS OF NaCl,Na 2SO 4 AND Na 2CO 3

Wheat seedlings (4 days old) were treated with Hoagland solution contained NaCl,Na 2SO 4 and Na 2CO 3 with the concentrations of 25 mmol/L,50 mmol/L,100 mmol/L and 200 mmol/L. The content of the organic free radical and the rate of production of the superoxide radical in the leaves of the wheat incveased and the membrane leakage increased too. Under the stress of low concertration, the effect of NaCl is greater than that of Na 2SO 4, but under the stress of the high concertration, the effect is contrary. The effect of Na 2CO 3 is the greatest. The results showed the good relationships existing between the content of free radical and membrane leakage of wheat leaves. The results showed that the salt stress the increase of the content of free radical, then the free radical affected the membrane leakage through the peroxidation and finally the growth of the wheat was affected by salt stress.