丛枝菌根真菌作用下桉树对土壤中Pb、Zn和Cd的耐受机理研究-环境工程专业论文.docx

Pb 和 Cd 向活性更低的化学形态转化。增强根部滞留作用、细胞壁固持作 用和可溶组分区隔化作用，促进重金属向活性更低的形态转化，可能是 AMF 作用下桉树耐 Pb、Zn 和 Cd 的机理。 关键词：桉树 丛枝菌根真菌 铅 锌 镉 亚细胞分布 化学形态 STUDY ON THE Pb-, Zn- OR Cd-TOLERANCE MECHANISM OF EUCALYPTUS UNDER THE ACTION OF ARBUSCULAR MYCORRHIZAL FUNGI ABSTRACT In order to discussion the tolerance mechanism of Eucalyptus under the action of Arbuscular Mycorrhiza Fungi (AMF), subcellular distribution and chemical form of lead (Pb), zinc (zinc) and cadmium (Cd) in roots, stems and leaves of Eucalyptus were studied by the method of gradient centrifugation and sequential chemical extraction in pot experiments. Eucalyptus was cultivated in artificial soil with different concentration of Pb (0, 50, 100, 100 and 200 mg/kg), zinc (0, 50, 100 and 200 mg/kg) or Cd (0, 20, 40 and 60 mg/kg) respectively. With inoculated with AMF or non-inoculated with AMF, Eucalyptus was harvested after 12 weeks. The colonization rate of root inoculated with AMF, the biomass and heavy metal content in aerial part or underground part of Eucalyptus, and the subcellular distribution and chemical forms of Pb, Zn or Cd in roots, stems and leaves of Eucalyptus were determined respectively. The results showed that Pb, Zn or Cd accumulated mainly in underground part of Eucalyptus. The concentration of Pb, Zn or Cd in the Eucalyptus was reduced under high Pb, Zn or Cd stress inoculated with AMF, compared with non-inoculated. The distributing proportions of Pb, Zn or Cd were differently in various subcellular components in roots, stems and leaves of Eucalyptus. Pb or Cd was mainly bounded to the cell wall or distributed in the soluble fraction; Zn was mainly distributed in the cell wall or the soluble fraction, and then was bounded to nuclear fraction. Under high Pb, Zn or Cd stress, inoculation with AMF could strength binding capacity to them of the cell wall and the vacuolar compartmentalization. There were many chemical form of Pb, Zn or Cd in various parts of Eucalyptus. With the increase in Pb concentration of soi