Effect Of Cu, Pb And Their Interactions On The Physiological And Ecological Characteristics Of The Houttuynia Cordata Thunb

Based on field survey , soil and nutrient incubation methods , the effect of Cu ,Pb and their interactions on the physiological and ecological characteristics of the Houttuynia cordata Thunb was carried. This research is about the effect of Cu,Pb concents in three soil on Cu , Pb accumulating in the Houttuynia cordata Thunb, the effect of Cu ,Pb and their interactions on the growth of the Houttuynia cordata Thunb and Cu ,Pb accumulating, migration and allocation in the Houttuynia cor'data Thunb body, and the influence of Cu , Pb and their interactions on the physiological and biochemical characteristics and trace elements. The result of the study shows :1.The under ground stems of the Houttuynia cordata Thunb accumulating Cu,Pb shows as synergism function in yellow soils and rice soils,it shows as antagonism function in leaf and the over ground stems .The Houttuynia cordata Thunb accumulating Cu,Pb shows as synergism function in purple soils.It show that the Houttuynia cordata Thunb accumulating Cu,Pb has different interactions in defferent soils under natural condition.2.Adding small dose of Cu can promote the growth of the Houttuynia cordata Thunb , the concentration of treatment of Cu reaches 3.2mg/L will restrain the growth of the Houttuynia cordata Thunb in the nutrient solution, present the symptom of poisoning .Pb restrains the growth of the Houttuynia cordata Thunb, when the concentration of the treatment reaches 750mg/L in the nutrient solution, the plant dies. Cu-Pb interactions has little promotion on the growth of the Houttuynia cordata Thunb.The result shows the greater injury of Cu than that of Pb on the Houttuynia cordata Thunb. Though the effect of Cu-Pb interactions of the Houttuynia cordata Thunb is smaller than single function of Cu and Pb ,it influences the growth of the Houttuynia cordata Thunb.3.Along with the increase of Cu , Pb concentration, Cu and Pb accumulating dose increases significantly in the Houttuynia cordata Thunb .The trends of the Houttuyniacordata Thunb accumulating Cu fits best with the quadratic curve in the nutrient solution.The trend of accumulating Pb fits best with the logarithm curve.This indicates that the Houttuynia cordata Thunb has different accumulation regulation to Cu and Pb. Pb promotes the accumulation of Cu in over ground stems of the Houttuynia cordata Thunb,iX is not obvious to accumulate Cu in the part under the ground; Cu promotes the accumulation of Pb in the Houttuynia cordata Thunb. In the soil incubation , it is not significant to Pb accumulating Cu in the part of the Houttuynia cordata Thunb under ground. With the increase of Pb, Cu increases and then restrains in the over ground stem.Cu decrease Pb in the stem under ground, With the increase of Cu, Pb increases and then restrains in the over ground stem. It can be found that Cu and Pb in different medium ,different concentration, different position of the Houttuynia cordata Thunb has the different interactions.The rich collection ability to Cu of every position of Houttuynia cordata Thunb is the stem under the ground >the stem over the ground> the leaf, the rich collection ability to Pb is the leaf >the stem over the ground> the stem under the ground. It indicates that the part of the Houttuynia cordata Thunb over the ground has the better transporting ability to Pb.4.Under the condition of the nutrient solution, Cu and Pb promote the absorption of Fe in the Houttuynia cordata Thunb,vfhen the concentration is low. The high concentration suppresses the absorption of Fe; It can not influence obviously that Pb absorbs Mn in the Houttuynia cordata Thunb.Cu promotes the Houttuynia cordata Thunb to absorb Mn; As concentration of Cu and Pb treatment increasing ,the dose of Zn absorbing of the Houttuynia cordata Thunb increases after reducing; The trends of Cu-Pb interactions to the Houttuynia cordata Thunb absorbing Fe and Mn in the over ground is not obvious, to the under ground part absorbing Mn and the over ground department absorbing Zn restrains, to the under ground part absorbing Zn increases. In soil incubation, Cu-Pb reciprocation has reduced Fe content in the stem over the ground, promotes the under ground stem to absorb Mn ,which can not influence significantly as to absorb Mn and Zn in the leaf.5.Cu and Pb reduce the content of chlorophyll a , chlorophyll b and chlorophyll a +b in the lamina of the Houttuynia cordata Thunb significantly. With the increasing of Cu treatment concentration, the activity of SOD declines after rising, the activity of POD andCAT rises gradually. With the increasing of the Pb treatment concentration, the activity of SOD ,POD and CAT all declines after rising. Cu-Pb interactions can increase the content of chlorophyll in the lamina of the Houttuynia cordata Thunb, restrain the activation of SOD and POD. It is not significant to influence the trend of CAT.