油菜对Cd污染土壤的修复潜力分析

以甘蓝型油菜为研究材料,利用盆栽试验研究了不同浓度Cd(0,1,2mg/kg)胁迫下油菜的吸收特性,以及土壤微生物群落结构变化.结果表明:随着Cd浓度的升高,油菜植株对Cd的吸收显著增加,而且油菜地上部分的吸收量显著高于地下部分,其中茎的Cd浓度最高,籽粒最低;油菜将Cd从地下转移到地上部分的转运系数随外源Cd浓度的升高而呈现先升高后下降的趋势;且低浓度Cd处理下,油菜对Cd的转运系数较高,修复效率可以达到6.841%~7.752%.土壤微生物多样性分析发现,Cd改变了土壤微生物群落的结构,降低了部分优势菌群的相对丰度,而油菜可以增加这些菌群的相对丰度,提高土壤微生物多样性.因此,种植油菜有利于土壤生态系统的稳定性,可以用于修复中等程度Cd污染土壤.

Analysis of the Potential Remediation of Oilseed Rape to Soils Contaminated with Cadmium

The pot-experiment was conducted to analysis the absorption characteristics of oilseed rape and the change of soil microbial community structure under different Cd concentrations. Results indicated that the absorption of Cd in the plant increased significantly as the rising of Cd concentrations, and the content in the shoot was higher than that of roots. Cd concentration in stem was the highest, and Cd concentration in seed was the lowest. The translocation factors (TFs) of Cd in oilseed rape showed a trend of first increasing and then decreased with the rising of Cd concentrations. At a low Cd concentration, the translocation factors (TFs) of Cd in oilseed rape was higher and the remediation rate can reach 6.841~7.752%. Soil microbial diversity analysis showed that Cd contamination altered soil microbial community structure and reduced the relative abundance of some dominant bacteria, but cultivation of oilseed rape can increase the relative abundance of them, and increased the soil microbial diversity. Therefore, cultivation of oilseed rape is beneficial to the stability of soil ecosystem and can be used to remediate the Cd-contaminated soil.