The Studies On Pb-Zn Enrichment, Physiological And Biochemical Character Of Pseudostellaria Maximowicziana(Franch.et Savat.) Pax To Pb-Zn Stresses

The dissertation taked the dominant plant species from the Tangjia,Wusihe and Tuanbao mountain lead(Pb)-zinc(Zn)mine of Hanyuan county in Sichuan province as riddling objects,through the field survey and analysis in the fourteen plants,it was found that the enrichmentalabilities of Pb,Zn in the Pseudostellaria maximowicziana(Franch.et Savat.)Pax was stronger than that of other species.The concentration of Pb,Zn were nearly reached those of the soil.It showed widely-spread and great biomass in the mine areas.Based on the above reasons,its accumulation character and ecophysiological responses were studied in this paper,the main results were showed as follows:1.During the fourteen dominant plants in the mining areas,the enrichment, bio-concentration and translocation coefficients of Pseudostellaria maximowicziana (Franch.et Savat.)Pax which possessed basic characteristics of accumulators were better than those of other species,the average Pb,Zn contents in roots of Pseudostellaria maximowicziana(Franch.et Savat.)Pax were 1018.33mg/kg,1102.90mg/kg respectively, while in shoots were 728.30mg/kg,1034.10mg/kg respectively,the average Pb,Zn bio-concentration coefficients in roots were 0.85,0.87 respectively,while in shoots were 0.76,0.85 respectively,the average Pb,Zn translocation coefficients were 0.81,0.86 respectively,the contents of Pb,Zn reached or overpassed those of the soil.the results indicated that it was an accumulator of Pb,Zn.2.In the potted experiment,it indicated that:(1)The root activity presented the tendency of increasing with the increase of the heavy metals' concentration,the highest root activity(1.398mgTTF/(g·h))which increased by 433.92%comparing with the control was attained by the plants at Pb/Zn levels of 400/500 mg/L treatment,while the contents of chlorophyll contents,dry weight and root/shoot ratio had similar tendency when the the heavy metals' concentration increased.in comparison with the control,the maximum root(1.62g/plant)and shoot(10.33g/plant) biomass which was 6.23,5.55 times than the control,respectively.(2)There were the tiny differences among the antioxidant enzyme systems in shoots under the stress of Pb,Zn with the increase of the heavy metals' concentration,on the whole,with the increase of the Pb concentration,the activities of peroxidase(POD) superoxide dismutase(SOD)and catalase(CAT)rose at first and lowered later,while the content of MDA was decreased first and increased afterwards.(3)The soluble carbohydrate contents in shoots of Pseudostellaria maximowicziana (Franch.et Savat.)Pax increased with the increase of Pb,Zn concentrations.The soluble protein contents in shoots rose at first and lowered later with the increase of Pb,Zn concentrations.It indicated that the soluble carbohydrate and soluble protein contents in shoots were enhanced under the stresses of Pb,Zn.(4)The distribution of Zn in diferent plant parts was:shoots＞roots,however,the Pb, Zn translocated was:roots＞shoots.generally speaking,the Pb,Zn contents in roots and shoots,the translocated amount and translocation coefficients increased with the increase of Pb,Zn concentrations,the highest Pb,Zn contents in roots of Pseudostellaria maximowicziana(Franch.et Savat.)Pax were 1386.08 mg/kg,9250.50 mg/kg respectively, while in shoots were 1197.93 mg/kg,8243.15 mg/kg respectively,the highest Pb,Zn bioconcentration coefficients in roots were17.4,76.5 respectively,while in shoots were13.5, 66.5 respectively,the highest Pb,Zn transportation coefficients were0.90,0.93 respectively. the highest total Pb,Zn translocated were11.73mg/plant,82.71mg/plant respectively,the average Pb,Zn translocated occupied the 0.80,0.10%of dry weight respectively,while the highest were 0.93 percent,0.12 percent respectively.(5)The Pb,Zn concentration had synergy effect of inhibiting to the Pb,Zn content in roots,shoots,also had a highly significant linear relationship,there were highly significant positive correlations between the different Pb,Zn concentrations and the Pb contents in roots and shoots,the correlation coefficients were 0.890^**,0.884^**,0.625^**and 0.610^**respectively.also there were extremely significant positive correlations between the different Pb concentrations and the Zn contents in roots and shoots,the correlation coefficients were 0.718^**and 0.722^**respectively,while significant positive correlations between the different Zn concentrations and the Zn contents in roots,meanwhile, extremely significant positive correlations in shoots,the correlation coefficients were 0.501^* and 0.539^**respectively.3.We conclude that Pseudostellaria maximowicziana(Franch.et Savat.)Pax,which is tolerant to Pb,Zn,could translocate lead,zinc from the roots to the shoots,so it should be preferred agents phytoremediation of Pb,Zn polluted areas.