Study On Cu-Zn Accumulation Characteristics And Physiological Mechanism Of Myriophyllum Aquaticum

The disseration taked the advantage of aquatic plant from the chengdu plain pollution rivers as the object of screening. through the field survey of different plants. Use Cu and Zn for culture two kinds of heavy metal processing, Cu concentration respectively0(CO),100(C1),200(C2),300(C3),400(C4),500(C5) mg/kg;Zn concentration respectively0(Z0),100(Z1),200(Z2),300(Z3) mg/kg; CK for Z0C0. Through the indoor potted controlled trials. It was found that emergent aquatic plant myriophyllum aquaticum was a accumulator for Cu; The enrichment characteristics and physiological mechanisms were studied in this dissereation. The results showed:1.The research river has rich vegetation types, phyletic and various.the content of Cu Lead of7dominant plants in shoots are30.14mg/kg-486.21mg/kg,the content of Zn in shoots are44.36mg/kg～113.41mg/kg,The content of Lead in shoots of Myriophyllum aquaticum is486.21mg/kg,and is the highest in the7dominant plants. The Cu translocation coefficients and bioconcentration coefficients of Myriophyllum aquaticum are0.78、0.29and2.61.2.Under the Cu,Zn stress. Only the Cu or Zn stress the roots of content heavy metal were more than the shoots. The results were instead when the composition of Cu and Zn. The highest Cu concentrations in root and shoot of myriophyllum aquaticum were631.94mg/kg and964.02mg/kg respectively, while the highest Zn concentrations were390.32mg/kg and467.16mg/kg respectively. The highest Cu,Zn accumulation coefficients were5.13and2.74. The highest Cu,Zn translocation coeffieients were2.28and1.63. Under the composition of Cu and Zn, myriophyllum aquaticum hyperaccumulation threshold to aboveground Cu content (plant aboveground Cu content is1000mg/kg is the Cu hyperaccumulation plants), showed strong enrichment ability for Cu,So, myriophyllum aquaticum was a new Cu enrichment plant.3. The low concentrations of Cu-Zn compound pollution of myriophyllum aquaticum growth has certain promoting effect, whether single or compound pollution, myriophyllum aquaticum biomass are along with the increase of concentration of Cu-Zn overall showed decreasing trend after first increases, and under the Z0C4(Cu:400mg/kg) reached a maximum of24.45g/plant.4.The effects on myriophyllum aquaticum physiological by Cu-Zn pollution. Found that the myriophyllum aquaticum chlorophyll centent significantly by Cu-Zn polltution. It maked the chlorophyll content decreased obviously by the different concentrations of Cu-Zn pollution; Only Cu or Zn pollute, the soluble protein content showed a gradually decreased with the increase of Cu-Zn concentrations.While the same with soluble sugar content. But after Cu-Zn composite treatment. The content of the change appears to rise after a fall. It showed that under the condition of cu, zn pollution, myriophyllum aquaticum can regulate, soluble protein and soluble sugar content in its own to form the self protection mechanisms and art.But all lower that controls. It showed that the myriophyllum aquaticum have the carbon and nitrogen metabolism exists certain printing effect by Cu-Zn pollution.5.The effects on plant protective enzyme by Cu-Zn pollution. It showed that MDA has rising when the Cu concentration increase and the content of leaf MDA content than the root. When the concentration of Zn was certain the root and leaves SOD activity with the increase of the concentration of Cu rising.while the activity of POD after the first rise fall to rise again. But the activity of CAT after the first drop rise and fall. It showed that a certain concentration range of Cu-Zn pollution showed myriophyllum aquaticum a physiological adaptation mechanism of active resistance to stressFrom this study:the emergent aquatic plant myriophyllum aquaticum can grow under Cu-Zn pollution, compared with other aquatic plants the biomass is bigger, prove that it has good tolerance and resistance; And for Cu in the Cu-Zn compound pollution of enrichment capability is strong, the absorption of Cu reached a point of hyperaccumulation plants, and the transfer coefficient and the concentration coefficient is greater than1, So myriophyllum aquaticum is a Cu enrichment plant. So it Can be applied to Cu pollution area to the repair of Cu in water and enrich the rich product plant resource of water pollution.