Effects of Heavy Metal Enrichment on Ca Uptake in Submerged Plants

The common submerged plants in Xuanwu Lake （Vallisneria natans （Lour.） Hara,Ceratophyllum demersum L.,Hydrilla verticillata （Linn.f.）Royle,Potamogeton crispus L.）were selected as research objects.Quantitative and qualitative analysis of heavy metal elements in plants were carried out and the research focused on the interaction between Ca and heavy metal elements in plants,in order to provide a theoretical reference basis for the correct understanding and utilization of submerged plants for controlling heavy metal pollution in water.The results showed that the four submerged plants had different accumulative capacities for different heavy metal elements;the content of Fe in Vallisneria natans （Lour.）Hara,Zn,Cd in Ceratophyllum demersum L.,Pd in Hydrilla verticillata （Linn.f.）Royle,and Cr,Ni,and Cu in Potamogeton crispus L.were relatively high.The average content of Ca in the four submerged plants were as follows,Hydrilla verticillata （Linn.f.）Royle(112 146.24mg·kg^-1)＞Ceratophyllum demersum L.(79 375.71mg·kg^-1)＞Potamogeton crispus L.(36.59mg·kg^-1)＞Vallisneria natans （Lour.）Hara(53 441.44mg·kg^-1).There was a significant negative correlation between Ca and Pd in the four submerged plants（P＜0.05）.There was a extremely significant positive correlation between Ca and Cr in Vallisneria natans（Lour.）Hara（P＜0.01）.