荠菜和油菜对镉污染土壤的修复效应研究

Research on Phytoremediation of Cadmium Polluted Soil by Capsella bursa-pastoris and Oilseed rape

以荠菜(Capsella bursa-pastoris)和油菜(Oilseed rape)为试材,采用盆栽试验研究了荠菜和油菜对不同水平Cd污染的耐性及富集效应,并施加不同水平螯合剂初步探讨了荠菜和油菜净化重金属污染土壤的应用潜力。结果表明:荠菜和油菜的株高、干重和叶绿素含量等在低水平Cd处理时轻微的促进,而在高水平Cd处理中受到抑制,在土壤Cd添加量为120mg/kg时,荠菜和油菜的株高、干重和叶绿素含量达到最大;荠菜和油菜植株中脯氨酸含量随Cd添加量的增加而增加,当土壤Cd含量为200mg/kg时,荠菜和油菜体内脯氨酸含量达到最高,分别比对照升高了16.57、17.95倍;荠菜和油菜体内Cd含量大小均表现为:地下部>地上部>籽实,各部位Cd含量均随着土壤Cd添加量的增加呈先增加后降低趋势,并在土壤Cd添加量为120mg/kg时达到最大值,此后则急剧下降;荠菜和油菜不同部位Cd含量与不同水平处理Cd浓度之间的回归方程均达到显著性水平(P<0.01),间接表明添加Cd处理后土壤中Cd能被植物有效吸收,并且各部位对Cd的吸收主要依赖于土壤中Cd含量的变化;荠菜和油菜具有修复Cd污染土壤的潜力,二者对重金属Cd的吸收富集表现出较为一致的特点,但相比之下,荠菜对土壤中Cd的吸收富集能力强于油菜;荠菜和油菜地上和地下部Cd含量随着螯合剂浓度的增加而逐渐增加,添加螯合剂能明显提高荠菜和油菜对土壤中Cd的转运和吸收。

Taking Capsella bursa-pastoris and Oilseed rape as test materials,the Cd tolerance,uptake and accumulation of Capsella bursa-pastoris and Oilseed rape under different Cd concentration in soil,and to enhance the remediation effect by adding chelator was studied.The results indicated that low concentration of Cd could increase the plant height,dry weight and chlorophyll contents of oilseed rape to some extent,while high concentration of Cd restrain the growth of Capsella bursa-pastoris and Oilseed rape,when Cd concentration was 120mg/kg,the plant height,dry weight and total chlorophyll content of Capsella bursa-pastoris and Oilseed rape was the highest.The proline content of Capsella bursa-pastoris and Oilseed rape increased with the increase of Cd in soil,when Cd concentration was 200 mg/kg,The proline content increased by 16.57 times and 17.95 times respectively compared with control.The accumulation of Cd in roots was much higher than that in shoots and seeds,the Cd contents in different parts of Capsella bursa-pastoris and Oilseed rape were significantly increased with the increase of Cd in soil,reached the highest content when Cd concentration was 120mg/kg,after that,the Cd content were decreased sharply.The Cd contents in different parts of Capsella bursa-pastoris and Oilseed rape were significantly correlated with concentration of Cd in soil,which showed that the concentration of Cd in soil could be absorbed by plants effectively and the Cd contents in different parts were mainly depended on the concentration of Cd in soil.Capsella bursa-pastoris and Oilseed rape was a promising crop to be used for phytoremediation on Cd contaminated soil,and the characteristics of Cd absorption and accumulation by the two plants were uniform which Capsella bursa-pastoris was higher than Oilseed rape.The Cd contents of above-ground and under-ground of Capsella bursa-pastoris and Oilseed rape increased with the increase of chelator which could obviously improve the transshipment and absorption of Cd in soil.