南京栖霞重金属污染区植物富集重金属效应及其根际微生物特性分析

以南京栖霞重金属污染区5种植物及其根际土壤为研究对象,对植物富集重金属特征以及重金属含量与根际土壤细菌数量、土壤酶活性等的相关性进行了调查分析。结果发现,植物根际重金属污染物以Zn和Cd为主;重金属污染地区的植物有较强的吸收重金属能力,龙葵和茼草具备了超积累植物的基本特征;植物根际细菌和Pb抗性细菌的数量达到了107CFU g-1土;根际土壤酶活性未受到重金属的毒害或受到的毒害很小;植物体中重金属含量与土壤重金属含量及其存在状态、土壤酶、土壤重金属抗性细菌有显著的正相关性。根际土壤细菌尤其是具有重金属抗性的活性细菌可能会促进土壤重金属的活化,由此促进植物体对重金属的吸收和转运。

Phyto-accumullation of heavy metals and characteristics of rhizospere microbes in heavy metal contaminated soils Qixia, Nanjing

Five species of plants and their rhizospheric soils were sampled and collected from heavy metal contaminated soils in Qixia, Nanjing for analysis and exploration of characteristics of phyto-accumulation and relationships of contents of heavy metals with population of bacteria and activity of soil enzymes in the soil. It was found that the heavy metal pollutant in the rhizosphere was dominated with Zn and Cd; and the plants growing therein were quite high in heavy metal absorbing capacity. Beckmannia grass and Solanum nigrum featured the characteristics of a heavy metal hyperaccumulator plant. The numbers of bacteria and Pb-resistant bacteria in the rhizospheric soil both reached up to 107 cfu g-1 of soil. The activities of soil enzymes were little inhibited. Significant positive relationships were observed of heavy metals contents in the plant with contents and forms of the heavy metals in the soil, soil enzymes activity, and Pb-resistant bacteria. Soil bacteria in the rhizosphere, heavy metal-resistant bacteria in particular, may improve bioavailability of heavy metals in soil, thus promoting uptake and transport of heavy metals by plants.