盐胁迫对珠美海棠和山定子膜保护酶系统的影响

Effect of salt stress on protective enzyme system of membrane in Malus zumi and M.baccata

实验以耐盐种珠美海棠(MaluszumiMats)和盐敏感种山定子[Malusbaccata(L.)Borkh]为试材,比较研究了在盐胁迫下叶片质膜透性、叶绿素和丙二醛(MDA)含量、膜保护酶超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性及根质膜透性的变化,为探索苹果属植物耐盐机制提供素材。结果表明,盐胁迫对根质膜透性没有明显的影响;但导致叶片质膜透性增加,盐敏感种山定子的质膜透性高于耐盐的珠美海棠。随盐胁迫加重,叶绿素a、b含量降低,叶绿素a/b比值增加,类胡萝卜素变化不明显。MDA含量随盐胁迫而升高,但珠美海棠低于山定子。山定子叶片中SOD、POD、CAT活性随盐胁迫加重而降低,而珠美海棠SOD活性在盐胁迫下保持稳定,POD、CAT活性增高。由此可见珠美海棠在盐胁迫条件下有活性较高的膜保护酶系统。

The Malus zumi and M. baccata were used as materials for studying the effect of salt stress on protective enzymes system of membrane. The results showed that： under salt stress, the MDA content and membrane permeability in leaf increased, especially under 100 mmol/L NaCI stress the membrane permeability ofM. baccata （L.） Borkh. increased enormously, which showed the membrane had been destroyed intensively. The chlorophyll a （chla）, chlorophyll b （chlb） content decreased, the chla/chlb increased, but the carotenoid content kept constant. The root membrane permeability didn＇t show obvious changes. The membrane protection enzymes, SOD, POD and CAT decreased for M. baccata CL.） Borkh., whereas the SOD kept constant and POD and CAT increased for M. zumi Mats. It is suggested that the salt tolerance ofM. zumi Mats was better protected against active oxygen species under salt stress than M. baccatct （L.） Borkh. and had stronger membrane protection enzyme system.