P·Cd·Zn交互作用对沉水植物吸收积累P·Cd·Zn的影响

目的]研究P、Cd、Zn交互作用对沉水植物吸收积累P、Cd、Zn的影响。方法]采用溶液培养的方法,模拟Cd、Zn重金属污染和P富营养化污染环境,研究P、Cd、Zn交互作用对沉水植物吸收积累P、Cd、Zn的影响。结果]对于黑藻施加P浓度为1mg/L范围内,P与低浓度Cd、Zn之间为协同关系,施加P促进植物体对Cd、Zn的吸收积累。对于伊乐藻在P浓度为5～50mg/L时,P与高浓度Cd、Zn之间为拮抗关系,随着P浓度的增加,植物体内Cd、Zn含量呈下降趋势。黑藻与伊乐藻对P的吸收积累有一个平衡态,约为20～23mg/g。结论]湖泊环境中当重金属及富营养化污染同时存在时,重金属对植物的胁迫是污染的主要因素,而富营养化元素在一定程度上还可以缓解这种重金属对植物的毒害作用。

Effects of P-Cd-Zn Interactions on the Absorption and Accumulation of Submerged Macro-phytes to P, Cd and Zn

Objective] This study was to explore the effects of P-Cd-Zn interactions on the absorption and accumulation of submerged plants to P,Cd and Zn.Method]Employing the hydroponic culture to simulate the Cd,Zn heavy metal contamination and P eutrophication environment,we studied the effects of P-Cd-Zn interactions on the absorption and accumulation of submerged plants to P,Cd and Zn.Result]For Hydrilla verticillata,in the presence of 0-1 mg/L P,it showed a synergy relationship with low concentrations of Cd and Zn,suggesting that P could promote the absorption and accumulation of plants to Cd and Zn.For Elodea nuttallii,in the presence of 5-50 mg/L P,it showed an antagonistic relationship with high concentrations of Cd and Zn.The contents of both Cd and Zn in plants showed a declining trend with the increase of P concentration.H.verticillata and E.nuttallii had an equilibrium threshold of absorption and accumulation to P（20-23 mg/g）.Conclusion]When the heavy metals and eutrophication pollutions both existed in the lake environment at the same time,the stress of heavy metal on plants is the major cause of pollution,while eutrophication can to some extent alleviate the toxic effect of heavy metals to plants.