Studies On The Cu Absorption And Its Mechanisms Of Pol-ygonum Lapathifolium

With the discharge of the industrial “three wastes”, municipal solid waste emissions, the unreasonable use of high Cu fungicides, pesticides, and fertilizers, the Cu pollution of soil is worse and the Cu poison to plants gradually emerged.With a Polygonum Lapathifolium as material and through pot experiment, this study explored the effects of copper stress on Polygonum Lapathifolium and its ability of copper enrichment. Using the mycorrhiza inoculation to improve the effect of the capacity of the copper enrichment was also studied, so as to lay a foundation for the phytoremediation of copper contamination.The study showed that the Polygonum Lapathifolium had normal growth when copper concentration was lower than600mg·kg-1in the soil. The PolygonumLapathifolium could absorb a certain amount of copper, up to67.1mg·kg-1; Rumex absorb copper as while as absorbing of nitrogen phosphorus and potassium.The copper had different influences on Polygonum Lapathifolium in growth and development, physiological metabolism, soil enzyme activity and soil microbial quantity. With the increasing of copper concentration, the leaf length, leaf width, plant height and leaf area was decreased. Chlorophyll content decreased under the stress of copper, compared with CK. MDA contents in200,400,800,1000mg·kg-1Cu were lower than that of CK, decreased by34.40%,32.47%,20.25%, and27.65%. In the600mg·kg-1treatment, there was no obvious difference compared with Ck. In200,400,600,800mg·kg-1concentration of Cu treatment, POD activity was significantly higher than that of CK, about22.2times,13.3times,9.12times,6.35times respectively. SOD activity under the treatment of1000mg·kg-1increased significantly by50.45%. However SOD activity had no significant difference between other treatments; with the increase of the concentration of Cu, the activity of CAT also showed an increasing trend, CAT of800,1000mg/kg treatments showed the highest activity, about2.25times,2.41times. Compared with CK, the activity of cellulase under copper stress reduced significantly, especially when the concentration was800mg·kg-1. Cellulose activity is the lowest and the decline was94.34%.But when Cu concentration was600mg·kg-1, the difference was not significant compares with control. The activity of invertase decreased when the copper concentrations were200mg·kg-1and1000mg·kg-1. The invertase activity was decreased by61.94%and59.91%. When under1000mg·kg-1treatment, thecatalase activity was the lowest, only25.95%of the control. When the copperconcentration was1000mg·kg-1, urease activity was the lowest,70.03%lower ofCK. Bacterial number increased under800,1000mg·kg-1treatments. When Cu treatments was400,1000mg·kg-1, the number of fungi were more than that of CK.The study also found that mycorrhiza fungi inoculation increased the Cuabsorption. While inhibited the capacity of absorption NP (nitrogen, phosphorus) andimproved the activity of POD and CAT, promoted the synthesis of chlorophyll.However it has no significant effects on MDA content and POD activity, but it canimprove the activity of POD and CAT, promote the synthesis of chlorophyll.