太湖梅梁湾不同沉积物对3种沉水植物生长的影响

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

在人工栽培的条件下,研究了太湖重污染区梅梁湾2种不同沉积物(湖泥、岸泥)对苦草(Vallisneria natans(Lour.)Hara)、黑藻(Hydrilla verticillata(Linn.f.)Royle)、马来眼子菜(Potamogeton malaianusMiq.)3种沉水植物生长的影响.在上覆水相同条件下,湖泥中培养的3种沉水植物均生长良好,生物量高,分枝较多,其中苦草最为显著,生长在湖泥中的苦草比岸泥中的植株高,且提前发育成熟至生殖生长阶段;在湖泥中,3种沉水植物的叶绿素含量均较高,苦草在2种不同沉积物中的差别最大,叶色区别明显;在湖泥中,苦草、黑藻的根长及根系活力等指标均高于岸泥,但岸泥中的根较为粗壮,根数相对较多.试验结果表明:苦草、黑藻、马来眼子菜3种沉水植物能够适应梅梁湾湖泥的肥沃底质条件,生长发育正常,可以进行现场引种栽培试验.

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.