Effects of Cu on the growth and scavenging system of activated oxygen of Cynodon dactylon

The effect of Cu pollution on seeding growth and ecophysiological index of C.dactylon was studied by water cultivation experiments.At low concentrations of Cu(10 mg/L),the growth of C.dactylon seedling was maintained,while CAT and POD in the activated oxygen metabolism system and the MDA content of leaf cells increased slightly.In general,with an increase of Cu concentration,there was an obvious negative effect on the growth of C. dactylon seedlings.Seedlings exposed to high concentrations of Cu were shorter and smaller,with shorter and fewer fibrous roots,and their fresh/dry weight and leaf chlorophyll contents were drastically reduced.Meanwhile,as Cu concentration increased,the membrane penetration,electric conductivity,velocity of O2·-production and MDA content of leaf cells increased.Furthermore,the activated oxygen metabolism system was destroyed and as the balance of the protective enzyme system was broken,the activities of SOD,POD and CAT significantly decreased.