Effects of different sediments from Meiliang Bay of Taihu Lake on the growth of three submersed aquatic macrophytes

The effects of two different sediments(lake sediment vs.bank sediment) from the heavily polluted Meiliang Bay of Taihu Lake were investigated on the growth of three submersed aquatic macrophytes using artificial culture method.Vallisneria natans(Lour.)Hara,Hydrilla verticillata(Linn.F.) Royle,and Potamogeton malaianus Miq.grew well on the contaminated lake sediment when they were cultured in plastic tanks,and the biomass and shoot height of the three plants were also much higher than those cultured on the bank sediment in the same tank.The difference of V.natans in the two types of sediment was most obvious.The contents of chlorophyll a and chlorophyll b on the lake sediment were both higher than those cultured on the bank sediment in the same tank.The difference of leaf colour of V.natans between the two sediments was remarkable.The root vitality of V.natans and H.verticillata on the lake sediment was higher than that on the bank sediment.However,the roots of the two submersed aquatic macrophytes were stronger and the root number per shoot was high when grown in the bank sediment.The results showed that the three submersed aquatic macrophytes were able to grow normally under conditions of the overlying water and sediments from the heavily polluted area of Meiliang Bay of Taihu Lake.