重污染底泥对苦草（Vallisneria natans）和黑藻（Hydrilla verticillata）繁殖体萌发及幼苗生长的影响

为探究重污染底泥对沉水植物繁殖体萌发和幼苗生长影响，以苦草（Vallisneria natans）种子和黑藻（Hydrilla verticillata）冬芽为研究对象，以轻污染底泥为对照组，通过室内模拟实验研究了重污染底泥对两种繁殖体萌发和幼苗生长、生理特性的影响。实验结果表明，与轻污染底泥相比，重污染底泥对苦草种子萌发和幼苗生长无显著影响。黑藻冬芽萌发和幼苗地上部生物量在两组间没有显著差异，但重污染底泥组幼苗的地下部生物量显著高于轻污染底泥组，其地上部和地下部生物量比值由7.06±0.38下降至2.97±0.08。此外，苦草和黑藻幼苗受到重污染底泥胁迫表现出不同的生理响应。苦草幼苗叶片的类胡萝卜素含量显著减少，可溶性糖和蛋白含量分别降低11.56%、24.10%，根系活力也明显受到抑制，仅为（34.93±3.28） mg/（g·h）；黑藻幼苗生理响应与苦草略有不同，其叶片的叶绿素a、b含量显著增加，根系活力降低44.29%，可溶性糖和蛋白含量在轻污染组和重污染组之间无显著差异。由此可见，重污染底泥对苦草种子和黑藻冬芽的萌发影响不显著，但会明显影响幼苗的生长发育和生理特性，研究结果为...

Effects of heavily polluted sediments on propagule germination and seedling growth of Vallisneria natans and Hydrilla verticillata

This study examined the influences of heavily polluted sediments on the germination of Vallisneria natans seeds and Hydrilla verticillata turions, as well as their seedlings'' growth and characteristics of physiological changes in the laboratory. Compared with the slightly polluted sediment groups, the heavily polluted sediment groups had no significant influence on the seeds'' germination or seedlings'' growth of V. natans. Both the turions'' germination and shoot biomass of seedlings of H. verticillata showed no significant difference between the two groups, but the root biomass accumulation of H. verticillata significantly increased in heavily polluted sediments, and the shoot-root ratio decreased from 7.06±0.38 to 2.97±0.08. In addition, the heavily polluted sediments affected the physiological properties of V. natans and H. verticillata. Specifically, the contents of carotenoid in the leaves of V. natans in heavily polluted sediment groups were significantly lower than in slightly polluted sediment groups. And the contents of soluble carbohydrate and soluble protein decreased by 11.56% and 24.10%, respectively. Furthermore, the root activity was only (34.93±3.28) mg/(g·h) in heavily polluted sediment groups. Different from V. natans, the contents of chlorophyll-a and chlorophyll-b in the leaves of H. verticillata were significantly increased in the heavily polluted sediment groups, the root activity decreased by 44.29%, whereas the contents of soluble carbohydrate and protein showed no significant difference between the two types of sediments. The results could provide a scientific basis for using propagule to restore submerged plants in eutrophic lakes with heavily polluted sediments.