The epiphytic bacteria are the most abundant microorganisms on marine macroalga. However, there are few studies on the distribution of these epiphytic bacteria on male and female Sargassum thunbergii. In this study, the composition and diversity of epiphytic bacterial communities on male and female S. thunbergii were investigated by using the traditional culture-based method and 16S rDNA high-throughput sequencing. The results showed that the dominant bacterial phyla and genera were the same on both male and female S. thunbergii. However, there were significant differences in the relative abundance of epiphytic bacteria at the genus level. Furthermore, male and female S. thunbergii had their own indicative species and specific bacteria. In addition, the predicted functions of the epiphytic bacteria mainly differed in transport and metabolism, environmental adaptation and spore development. This study enriches the baseline knowledge of epiphytic bacteria related to dioecious algae and paves the way for further studies of the relationships between epiphytic microbial communities and the sex of algae.

附生细菌是海洋大型藻类中数量最多的微生物。然而，关于这些附生细菌在雄性和雌性马尾藻上分布的研究很少。本研究采用传统的基于培养的方法和 16S rDNA 高通量测序研究了雄性和雌性S. thunbergii附生细菌群落的组成和多样性。结果表明，雄性和雌性S. thunbergii的优势菌门和属相同。然而，在属水平上，附生细菌的相对丰度存在显着差异。此外，雄性和雌性S. thunbergii有自己的指示物种和特定的细菌。此外，附生细菌的预测功能主要在运输和代谢、环境适应和孢子发育方面存在差异。本研究丰富了与雌雄异株藻类相关的附生细菌的基础知识，为进一步研究附生微生物群落与藻类性别之间的关系铺平了道路。