In aquatic ecosystems, large amounts of epiphytic bacteria living on the leaf surfaces of submerged macrophytes play important roles in affecting plant growth and biogeochemical cycling. The restoration of different submerged macrophytes has been considered an effective measure to improve eutrophic lakes. However, the community ecology of epiphytic bacteria is far from well understood for different submerged macrophytes. In this study, we used quantitative PCR, 16S rRNA gene high-throughput sequencing and functional prediction analysis to explore the structure and function of epiphytic bacteria in an aquatic ecosystem recovered by three submerged macrophytes (Hydrilla verticillata, Vallisneria natans and Potamogeton maackianus) during two growth periods. The results showed that the community compositions and functions of epiphytic bacterial communities on the submerged macrophyte hosts were different from those of the planktonic bacterial communities in the surrounding water. The alpha diversity of the epiphytic bacterial community was significantly higher in October than in July, and the community compositions and functions differed significantly in July and October. Among the three submerged macrophytes, the structures and functions of the epiphytic bacterial community exhibited obvious differences, and some specific taxa were enriched on the biofilms of the three plants. The alpha diversity and the abundance of functions related to nitrogen and phosphorus transformation were higher in the epiphytic bacteria of P. maackianus. In summary, these results provide clues for understanding the distribution and formation mechanisms of epiphytic bacteria on submerged macrophyte leaves and their roles in freshwater ecosystems.

在水生生态系统中，生活在沉水植物叶片表面的大量附生细菌在影响植物生长和生物地球化学循环方面发挥着重要作用。不同沉水植物的恢复被认为是改善富营养化湖泊的有效措施。然而，对于不同的沉水大型植物，附生细菌的群落生态学还远未得到很好的理解。在本研究中，我们采用定量 PCR、16S rRNA 基因高通量测序和功能预测分析来探索由三种沉水大型植物（轮枝藻、Vallisneria natans和Potamogeton maackianus ）恢复的水生生态系统中附生细菌的结构和功能。) 在两个生长期。结果表明，沉水植物宿主上附生细菌群落的群落组成和功能与周围水域的浮游细菌群落不同。10月份附生细菌群落α多样性显着高于7月份，7、10月份群落组成和功能差异显着。在三种沉水植物中，附生细菌群落的结构和功能表现出明显的差异，并且在三种植物的生物膜上富集了一些特定的类群。P. maackianus附生细菌的α多样性和与氮磷转化相关的功能丰度较高. 总之，这些结果为了解沉水植物叶片上附生细菌的分布和形成机制及其在淡水生态系统中的作用提供了线索。