重金属镉、铅胁迫下湿地植物丁香蓼的生理生化特征研究

The Physiological and Biochemical Characteristics of the Wetland Plant Ludwigia prostrata Roxbunder the Heavy Metal Pollution Stress of Cadmiumand Lead

为了研究乡土湿地植物对重金属污染的生理响应特征,并以此作为乡土植物修复湿地土壤重金属污染的可行性依据,以分布于乐安河上游重金属污染区域的优势湿地植物丁香蓼(Ludwigia prostrata)为研究对象,采用土培实验,设置不同浓度重金属镉、铅及其复合污染胁迫处理各盆栽中的土壤,经历2个不同培养周期后,分别测定不同重金属污染胁迫下丁香蓼的生长状况、叶绿素含量、抗氧化酶活性等指标.研究结果表明:Cd、Pb单因素污染或其复合污染均能抑制丁香蓼的生长,且抑制作用随着各污染物浓度的增加而增强;无论是Cd、Pb单因素或其双因素污染物对丁香蓼的胁迫均呈显著负相关;丁香蓼叶片的叶绿素a、b及叶绿素a+b的含量则随着重金属污染物胁迫浓度的增加而呈下降趋势;重金属Cd、Pb的单因素污染或其复合污染对丁香蓼叶片的超氧化物歧化酶(Superoxide Dismutase,SOD)活性的影响表现出不同的趋势.

The aim of the study was to investigate the physiological responses of the native wetland plants to the heavy metals and provide feasible basis for the remediation of soil heavy metal pollution the native wetland plants.The dominant plant named Ludwigia prostrata Roxbwere selected as the experimental materialswhich were collected in the upper reaches of Le＇an River,where were polluted by heavy metals. Different concentrations of heavy metals of cadmiumand lead as the contaminants stress condition were added to the potted soils of the plants byusing pot experiment methods,and the growth,different Chlorophyll contents,antioxidant enzyme activity and other indicators of L. prostrata was determinedunder the different heavy metals pollution stressafter two different growth cycles. The results show that both of the single pollution factor and the compound pollution factors of cadmium and leadcould inhibit the growth of L. prostrata,and the inhibitory effects increased with the increase of the pollutant concentration.Both the single pollution factor and the compound pollution factors of cadmium and leadhad a significant negative correlation with the stress of of L. prostrata,but the contents of chlorophyll a,chlorophyll b and the total contents of chlorophyll in the leaves of L. prostrata showed a decreasing trend with the increase of heavy metal concentration,andit showed different effects on the activities of superoxide dismutase（ SOD） in the leaves of L. prostrata under pollution stress of the single factor and the compound factors of cadmium and lead.