不同基质对四种沉水植物生长的影响

通过模拟试验，研究了太湖五里湖主要3种基质类型(沙石、生土、湖泥)对4种沉水植物(苦草、马来眼子菜、金鱼藻、轮叶黑藻)生长的影响. 结果表明，生长于沙石、生土、湖泥上的苦草和马来眼子菜平均生物量分别为72.37、126.25、134.10 g和40.0、72.10、90.70 g，而金鱼藻和轮叶黑藻平均生物量分别为0.27、6.58、73.64 g和0.17、3.26、84.42 g，说明湖泥较适合这四种沉水植物生长. 苦草和马来眼子菜对相对贫瘠的生土有较强的适应性，而金鱼藻和轮叶黑藻不适宜在生土中生长. 生长在沙石上的4种沉水植物的生物量和株高最低，其中金鱼藻和轮叶黑藻于试验期间死亡.苦草的根系活力(TTC)低于马来眼子菜，生长在沙石、生土、湖泥中苦草的根系活力分别为0、(0.16±0.05) mg·g^-1·h^-1和(0.36±0.33) mg·g^-1·h^-1，而马来眼子菜则分别为(2.68±0.34) mg·g^-1·h^-1、(2.30±0.77) mg·g^-1·h^-1、(5.24±0.67) mg·g^-1·h^-1. 叶绿素、质膜透性和丙二醛(MDA)的测定结果进一步证明了以上结论.此外，苦草、马来眼子菜和轮叶黑藻对基质有较强的沁氧能力，其大小顺序为苦草＞马来眼子菜＞轮叶黑藻.

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.