土壤Cu Zn Pb污染对蔬菜根伸长的抑制及毒性效应

Inhibition and Toxicity of Cu,Zn,Pb on Root Elongation of Vegetable in Contaminated Soil

采用室内盆栽试验观测了黄泥土上不同浓度Cu(0～2000mg·kg-1)、Zn(0～3000mg·kg-1)和Pb(0～5000mg·kg-1)污染下叶菜类蔬菜(小白菜和包菜)、根茎类蔬菜(萝卜和洋葱)和茄果类蔬菜(番茄和黄瓜)的根伸长,以阐明不同重金属及用量对蔬菜根生长的抑制及毒性效应。结果表明,相同Cu、Zn、Pb浓度下,番茄的根伸长抑制率最大,小白菜的根伸长抑制率最小,番茄对Cu、Zn、Pb的毒性响应最敏感,小白菜则不敏感;蔬菜对不同重金属的毒性响应不同,对Cu最敏感,Zn和Pb次之。种植蔬菜的土壤中有效态重金属含量与蔬菜根伸长均呈显著负相关(rCu=-0.782,rZn=-0.995,rPb=-0.982),表明重金属有效态是影响蔬菜根伸长的重要因素。

A pot experiment was conducted to observe the root elongation of leaf vegetables （pakchoi and cabbage ）, root vegetables （radish and onion ）, solanaceous vegetables （tomato and cucumber） in paddy soil which was polluted by different heavy metals at different concentra- tions （Cu 0-2 000 mg·kg^-1, Zn 0-3 000 mg·kg^-1, Pb 0-5 000 mg·kg^-1） in greenhouse, in order to clarify the inhibition and toxicity effects of different heavy metals on vegetables. The results indicated that the inhibition rate in tomato was the highest and the pakchoi was the lowest in the same concentrations of Cu, Zn and Pb contamination, so tomato was the most sensible to Cu, Zn, Pb, and pakchoi was insensible. The vegetables responded differently to different heavy metals, more sensible to Cu （copper） than to Zn （Zinc） and Pb （lead）. A significantly negative relationship was found between root elongation and available concentrations of heavy metals in the involved soil （rCu=-0.782＊, rZn=-0.995＊＊, rPb=-0.982＊＊）. In conclusion, the available heavy metal was one of the important factors in affecting root elongation of vegetables.