Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China.
Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China.
Sci Total Environ. 2020 Jan 20;701:134944. doi: 10.1016/j.scitotenv.2019.134944. Epub 2019 Nov 2.
This study investigated responses of the submerged macrophyte Vallisneria natans to a water depth gradient of 0.3-1.5 m in shallow lakes, and examined changes of morphology, physiological parameters, leaf-epiphytic bacteria community, and water purifying ability. Results of the morphological and physiological parameters (shoot height, root length, total chlorophyll, contents of soluble protein (SP) and malondialdehyde, activities of superoxide dismutase, catalase, peroxidase, glutamine synthetase, and alkaline phosphatase) indicated that 0.9-1.2 m was the optimal water depth for planting. Vallisneria natans suffered photoinhibition at the shallow water depth of 0.3-0.6 m and lipid peroxidation damage in water 1.2-1.5 m deep. Microbial analyses indicated that at the water depth of 0.6 m, the accumulated cyanobacteria led to the suppression of microbial organics decomposition and nutrient metabolism in the leaf biofilms. The water quality indicators (chemical oxygen demand, total nitrogen, total phosphorus, and fluorescent dissolved organic matter) also confirmed that 0.9-1.2 m was the optimal planting depth of Vallisneria natans. The results of this study provided theoretical guidance and technical support for the restoration of submerged macrophytes in natural shallow lakes.
本研究调查了沉水植物苦草在水深 0.3-1.5 米的浅水湖泊中的响应，并检测了形态、生理参数、叶附生细菌群落和水质净化能力的变化。形态和生理参数（株高、根长、总叶绿素、可溶性蛋白（SP）和丙二醛含量、超氧化物歧化酶、过氧化氢酶、过氧化物酶、谷氨酰胺合成酶和碱性磷酸酶活性）的结果表明，0.9-1.2 米是种植的最佳水深。苦草在水深 0.3-0.6 米的浅水区受到光抑制，在水深 1.2-1.5 米的深水区受到脂质过氧化损伤。微生物分析表明，在水深 0.6 米处，积累的蓝藻导致叶片生物膜中微生物有机物分解和养分代谢受到抑制。水质指标（化学需氧量、总氮、总磷和荧光溶解有机物）也证实 0.9-1.2 米是苦草的最佳种植水深。本研究结果为自然浅水湖泊沉水植物的恢复提供了理论指导和技术支持。
