Spatial distribution of bacterioplankton community in Hongchaojiang Reservoir and its relationship with environmental factors

Abstract:

[Objective] To elucidate the composition, spatial distribution and interaction between phytoplankton community and environmental factors in Hongchaojiang Reservoir. [Methods] The community structure and diversity of planktonic bacteria in Hongchaojiang Reservoir were analyzed based on the 16S rRNA gene high-throughput sequencing technology. The physical and chemical variables of the water were detected simultaneously. [Results] A total of 28 phyla, 79 classes, 168 order, 243 families, 325 genera and 85 species were identified. Proteobacteria, Actinobacteria, Cyanobacteria, Verrucomicrobia, Bacteroidetes and Planctomycetes accounted for 21.95%, 21.30%, 17.98%, 12.27%, 11.72% and 9.51%, respectively. The PCoA analysis based on bray-curtis distance showed that the nine sampling sites in Hongchaojiang Reservoir could be divided into three groups, with the bacterial community displaying a gradient change along the upstream and downstream. The perMANOVA test indicated significant differences among the groups. However, there was no significant difference of the diversity index among the groups. Mantel analysis further confirmed that the transparency (Trans), turbidity (Turb), total phosphorus (TP), nitrite nitrogen (NO₂N), nitrate nitrogen (NO₃N), chlorophyll a (Chlo), pH, dissolved oxygen (DO), oxidation reduction potential (ORP), specific conductivity (SPC), total dissolved solids (TDS), nutritional status (TLI) would affect the planktonic bacteria community structure significantly. [Conclusion] The spatial distribution of bacterioplankton in Hongchaojiang Reservoir is influenced by the combined effects of physical and chemical factors and agricultural activities. These results provided scientific references for understanding the spatial pattern of the plankton-bacterial community and its response to human activities as well as reservoir management.