U、Cd单一及复合污染对水芹生长和生理特性影响

Effects of single and combined pollution of uranium and cadmium on growth and physiological characteristics of Oenanthe javanica

通过土壤盆栽试验研究不同浓度的U、Cd单一及其复合污染对水芹的生长、叶绿素含量、根系活力、细胞膜透性和MDA含量的影响。结果表明:与对照相比,随U、Cd单一及其复合污染处理浓度的增加,水芹的生长受到显著抑制(P<0.05);水芹叶绿素含量逐渐减少,其中以Cd元素对水芹叶绿素b胁迫作用最显著;水芹根系活力在低浓度(15 mg·kg^(-1))时受到促进,而在高浓度(150mg·kg^(-1))时受到抑制;叶片相对电导率处理组数据均显著高于对照组,U胁迫作用强于Cd;叶片丙二醛含量与对照相比随处理浓度的增加呈上升趋势。比较U、Cd单一及其复合处理对水芹的胁迫效应表明,高U高Cd(U150 mg·kg^(-1)+Cd150 mg·kg^(-1))对水芹生长和生理影响最显著,水芹在低浓度U、Cd胁迫下具有较好的抗逆性,因此,其在低浓度U、Cd单一及其复合污染的土壤修复方面具有潜在应用价值。

The growth,chlorophyll content,root activity,cell membrane permeability and MDA content of Oenanthe javanica（Blume）DC were studied under uranium（U）and cadmium（Cd）alone and in combination in pot experiment.Results showed that U and Cd stresses significantly inhibited the growth of O.javanica（P0.05）when compared with the control.The inhibition increased with increasing concentrations of U and Cd.The chlorophyll content of O.javanica decreased remarkably under U and Cd stresses.Cadmium reduced the content of chlorophyll b of O.javanica more significantly than U did.The activity of O.javanica roots was enhanced by low concentrations（15 mg·kg^（-1））of U and Cd,but significantly inhibited at high concentrations（150 mg·kg^（-1））.The relative electrical conductivities of leaves were higher under U and Cd stresses than under CK,with U showing greater effect than Cd.Leaf MDA content increased as U and Cd concentrations in-creased.Combined applications of U and Cd（U150 mg·kg^（-1）＋Cd 150 mg·kg^（-1））had greater influences on O.javanica＇s growth and physiological characteristics than their single.The present findings showed that O javanica has high resistance to U and Cd,which has potential to remediate U and Cd single and combined pollution soils.