Abstract:

Heavy metal content in the soil near roots of Populus tomentosa at different ages,and Superoxide dimutase(SOD),Peroxidase(POD),Catalase (CAT),content of chlorophyll,permeability of cell membrane in the poplar various organs were studied.The trees located at sides of a road which was along a river,in Baoding,China.The results showed that the pollution of soil heavy was serious.SOD activity reduced with age of Populus tomentosa grown in the contaminative area.POD activity and content of chlorophyll increased at early stage and decreased later with age of Populus tomentosa,Variation of CAT activity had no relationship with the age of Populus tomentosa.Permeability of cell membrane was not difference over ages of Populus tomentosa.Variation pattern of allelopathic index of SOD,POD,CAT,Chlorophyll,permeability of cell membrane of different age Populus tomentosa in pollution area were inconsistent.Subordinate function value method （SFVM） was adopted in this paper to evaluate heavy resistance of Populus tomentosa in contaminative area comprehensively,the result indicated that the pollution capacity was 3 age＞10 age＞20 age＞30 age,which suggested that resistance ability was reduced with age of Populus tomentos.

Key words: highway, Populus tomentosa, heavy metal, anti-oxidative enzyme, allelopathic index