The Study Of Tolerance For Cu,Zn,Pb And Cd Combined Pollution Of Eight Common Species

The paper studied the remediation pollution of compound heavy metal in the soil.Select the common woody plants,Black Locust,Ulmus pumila,Salix matsudana Koidz,Ailanthus altissima(Mill.)Swingle,Broussonetia papyrifera(Linn.)L'Hér.ex Vent.,Populus L.Koelreuteria bipinnata Franch.var.integrifoliola(Merr.)T.Chen and Paulownia as experimental material.The effects of heavy metals Cu,Pb,Zn and Cd stress on the growth and physiological and biochemical indexes of 8 common tree species by the orthogonal experiment method.Comprehensive evaluation the heavy metal accumulation and tolerance of the 8 species.Screening tree species which can repair heavy metal pollution in soil.Which provide reference for selecting tree species to repair heavy metal pollution in soil.(1)Under the combined pollution of heavy metals Pb,Zn,Cd and Cu in soil,All tested plants showed different degrees of the victim's symptoms,With the extension of stress time,the degree of plant damage gradually increased.To observe the symptom of plant leaf,Found that the growth of Ailanthus altissima(Mill.)Swingle and Broussonetia papyrifera(Linn.)L'Hér.ex Vent.papyrifera good.Salix matsudana Koidz and Paulownia poor of growth.By comparing the tolerance index of plants,Black Locust,Ulmus pumila,Salix matsudana Koidz,Ailanthus altissima(Mill.)Swingle,Broussonetia papyrifera(Linn.)L'Hér.ex Vent.,Populus L.Koelreuteria bipinnata Franch.var.integrifoliola(Merr.)T.Chen and Paulownia were 105.78?76?99.56?65.11?106.11?114.89?71.22?56.89.Therefore,from the perspective of plant growth and development are 8 species of compound heavy metals pollution tolerance ability in order.Broussonetia papyrifera(Linn.)L'Hér.ex Vent.> Ailanthus altissima(Mill.)Swingle > Koelreuteria bipinnata Franch.var.integrifoliola(Merr.)T.Chen>Ulmus pumila>Black Locust>Populus L.>Salix matsudana Koidz>Paulownia.(2)Under heavy metal stressed,Disseded the changes of SOD,POD and CAT activity in plants,The study found that Ailanthus altissima(Mill.)Swingle,s SOD,POD and CAT on activity in cells were increased gradually.Broussonetia papyrifera(Linn.)L'Hér.ex Vent.,Koelreuteria bipinnata Franch.var.integrifoliola(Merr.)T.Chen and Ulmus pumila SOD,POD and CAT activity increased gradually and then decreased.And the activity of SOD,POD and CAT were still higher than CK.Salix matsudana Koidz and Paulownia SOD,POD and CAT were lower than CK.The changes of proline,MDA and relative electrical conductivity in plant cells were consistent.Under heavy metal stressed,Ulmus pumila,Salix matsudana Koidz,Ailanthus altissima(Mill.)Swingle,Broussonetia papyrifera(Linn.)L'Hér.ex Vent.,Populus L.Koelreuteria bipinnata Franch.var.integrifoliola(Merr.)T.Chen and Paulownia the contents of proline,MDA and relative electrical conductivity in plant cells were compared 1.13?1.22?1.16?1.29?1.08?1.02?1.33?1.47.The results show that the tolerance ability of compound heavy metal contamination among the 8 tree species were Broussonetia papyrifera(Linn.)L'Hér.ex Vent.> Ailanthus altissima(Mill.)Swingle > Koelreuteria bipinnata Franch.var.integrifoliola(Merr.)T.Chen>Ulmus pumila>Black Locust>Populus L.>Salix matsudana Koidz>Paulownia.(3)Analysis concentration and enrichment index of heavy metals,The sudyed show that 8woody species did not reach the standard of the super enrichment plants.Ailanthus altissima(Mill.)Swingle,Broussonetia papyrifera(Linn.)L'Hér.ex Vent accumulation amount and enrichment index were high then others.Ulmus pumila,Koelreuteria bipinnata Franch.var.integrifoliola(Merr.)T.Chen,accumulation amount and enrichment index were commonly.S Salix matsudana Koidz Populus L.,Ulmus pumila and Paulownia,Pb,Zn on the Cu,Cd heavy metal accumulation.Generally speaking,under the combined heavy metal stress,analyzed the changes of growth morphology,resistance index and physiological indexes in 8 tree species.Ailanthus altissima(Mill.)Swingle and Broussonetia papyrifera(Linn.)L'Hér.ex Vent.can be used as a preferred tree species to repair complex heavy metal pollution.Koelreuteria bipinnata Franch.var.integrifoliola(Merr.)T.Chen and Ulmus pumila can be used as build a group of species to repair pollution.Black Locust,Paulownia,Populus L.and Salix matsudana Koidz should not be used to repair complex heavy metal pollution.