Preliminary study on Zn accumulation of duckweed(Lemna minor Linn.) and antioxitant enzyme(SOD) activity response to Zn in Zn-polluted water

To check the abilities of Zn uptake and accumulation of duckweed(Lemna minor Linn.),experiments of growth,Zn accumulation and SOD activitial response to Zn in plant duckweed were performed with fresh plant in vivo.The results showed that growth of duckweed was affected by 5 mg/L Zn treatmenat in solution,indicating better resistance to Zn.SOD activity was at peak in 5 mg/L Zn treatmenat,indicating greater ability to eliminate ROS caused by excessive Zn.Zn contents in roots and thalluses of duckweed in vivo increased significantly with increase of Zn concentration in solution at 0-5 mg /L Zn.When Zn concentration was higher than 5 mg /L,Zn accumulation in duckweed was no more increased significantly.And,the plant was damaged by excessive Zn.Therefore,there is a stronger ability of Zn accumulation in duckweed and 5 mg /L Zn can be regarded as critical concentration in Zn-pollution water.