镉胁迫对桐花树光合·蒸腾作用及保护酶活性的影响

目的]探究镉胁迫对桐花树生理指标的影响。方法]通过砂土混培试验研究红树植物桐花树幼苗在含镉(Cd2+)浓度为(0、0.6、61、22、43、0 mmol/L)系列蒸馏水培养液〔盐度为10‰)中的某些生理特性的变化。结果]当培养液中Cd浓度低于6 mmol/L时,随Cd浓度的增加,叶片光合蒸腾作用增强,叶绿素含量、总糖含量增加,过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性有所提高。当Cd高于6 mmol/L时,桐花树幼苗的生长减缓,叶片光合蒸腾作用减弱,叶绿素含量、总糖含量减少,过氧化物酶(POD)、超氧化物酶(SOD)和过氧化氢酶(CAT)活性出现下降趋势。结论]该研究为阐明红树植物对Cd金属的抗性机制,治理海洋河口重金属污染提供了理论和实践依据。

Effects of Cd Stress on the Physiological Indexes in Aegiceras corniculatum

Objective] The aim of the research was to probe into the effects of Cd stress on the physiological indexes of mangrove plant Aegiceras corniculatum.Method] In the sand-soil mixed culture test,the changes of some physiological characteristics of the seedlings in A.corniculatum in distilled-water culture solution(salinity of 10‰) with Cd2+ concentration of 0,0.6,6,12,24,30 mmol/ L were studied.Result] When Cd concentration in culture solution was lower than 6 mmol/L,with the increase of Cd concentration,the photosynthesis and transpiration of leaves were strengthened,the contents of chlorophyll and total sugar were increased and the activities of peroxidase(POD),superoxide dismutase(SOD) and catalase(CAT) were enhanced.When Cd concentration was higher than 6 mmol/ L,the growth of A.corniculatum seedlings was slowly,the photosynthesis and transpiration of leaves were weakened,the contents of chlorophyll and total sugar were decreased and the decreasing trends appeared in activities of POD,SOD and CAT.Conclusion] The research provided theoretical and practical basis for clarifying the resistance mechanism of mangrove plant to Cd and controlling the heavy-metal pollution in oceans and estuaries.