[Effects of sediments on submerged macrophytes growth].

With mesocom experiment, this paper studied the effects of different sediments (sandstone, clay and mud) in Taihu Lake of China on the growth of four submerged macrophytes Vallisneria natans, Potamogeton malaianus, Hydrilla verticillata, and Ceratophyllum demersum. The results showed that among the test sediments, mud was more available. When growing on sandstone, clay and mud, the mean biomass of V. natans, P. malaianus, H. verticillata and C. demersum was 72.37, 126.25 and 134.10 g, 40.0, 72.10 and 90.70 g, 0.27, 6.58 and 73.64 g, and 0.17, 3.26 and 84.42 g, respectively. V. natans and P. malaianus had a stronger adaptability to the clay with lower nutrients contents, while H. verticillata and C. demersum didn't. All the test species grown on sandstone had the lowest biomass and shoot height, and H. verticillat and C. demersum were not able to survive by the end of the experiment. V. natans had a lower root activity (TTC) than P. malaianus, being 0, 0.16 +/- 0.05 and 0.36 +/- 0.33 mg x g(-1) x h(-1), and 2.68 +/- 0.34, 2.30 +/- 0.77 and 5.24 +/- 0.67 mg x g(-1) x h(-1) when growing on sandstone, clay, and mud, respectively. The oxygen release from the root systems of test submerged macrophytes was in the order of V. natans > P. malaianus > H. verticillata. The measurements of chlorophyll content, cell membrane permeability, and MDA also had the similar trends mentioned above.