Investigation Of Planktonic Bacteria Based On High-throughput Sequencing Of 16S RRNA Genes In Poyang Lake And Nanchang Section Of Ganjiang River

In order to get the diversity of the bacterioplankton community in the water of the Poyang Lake and Ganjiang River,high-throughput sequencing of the 16 S rRNA gene was used.Genome DNAwas extracted from the water samples in 6 sampling points,they are KangShan?MeiXi?XingZi?NanJiXiang?WuCheng and Nanchang section of Ganjiang River.Then we used Illumina HiSeq 2500 system to get sequences.We have obtained 2,532,733 Raw PEs,2,469,654 Clean Tags,2,410,401 Effective Tags.At 97%similarity,the sequences were assigned to 62127 operational taxonomic units(OTUs).We annotated OTUs in combination with the GreenGene database and got the Top 10 bacterioplankton at the Phylum level as Proteobacteria,Actinobacteria,Firmicutes,Bacteroidetes,Saccharibacteria,Planctemycetes,Verrucomicrobia,Cyanobacteria,Acidobacteria,Chlorobi.At the same time,we obtainedthe relative abundance of the top 10 strains at the level of Genus by further processing.They were hgcl-clade,Pseudomonas,Brevundimonas,Flavobacterium,CL500-9-marine-group Acidovorax,Massilia,Polynucleobacter,Candidatus-Planktophila and Acinetobacter.Poyang Lake planktonic bacteria community mainly by the Proteobacteria,Actinomycetes and Bacteroides.The dominant bacteria of the bacterioplankton in Poyang Lake are Proteobacteria(mainly Betaproteobacteria,Alphaproteobacteria and Gammaproteobacteria),Actinomyces and Bacteroidetes.This is consistent with the results of previous investigations.Our experimental results help to demonstrate Cohan's point that the abundance of different bacterial populations in the environment changes with the number of different genotypes within the population;that is,the dominant bacterial population in the environment genotypes are more diverse.Here,we hypothesized that the abundance of planktonic bacteria in the Poyang lake is the lowest in annual dry season abundance and then gradually increases.Until the wet season,the abundance of bacterioplankton bacteria reaches a maximum,and then,the bacterial abundance gradually decreases.The abundance of bacteria in the lake is similar to an oscillogram,where the peak of the wet season is the crest,and the dry season is the trough.By analyzing the box plots of Chao1 index,Shannon index and PD_whole_tree index,we have obtained the following conclusions(1)The abundance,diversity,and phylogenetic diversity of bacterioplankton bacteria in Lake Poyang Lake area have increased significantly with increasing ambient temperature.(2)The abundance,diversity,and phylogenetic diversity of bacterioplankton bacteria in the Lake District of southern are higher than that in the northern lake region;(3)The abundance,diversity,and diversity of bacterioplankton bacteria in the same lake region near the lake of mouth are higher than the other region;(4)From April to May 2016,the abundance of bacterioplankton in the Nanchang Section of Ganjiang River was significantly increased.Diversity and phylogenetic diversity were significantly increased.At the same time,we analyzed the composition of planktonic bacteria and found that their composition was at the gate.The composition of planktonic bacteria on water and Poyang Lake is basically similar.The abundance of planktonic bacteria in Poyang Lake is affected by the monsoon climate.The law is similar to that of waveforms.The peak is in the rain season and the trough is in dry season.The results also revealed the predominant bacterial population has a higher genotype diversityin the planktonic bacterial.This study provides more data for us to understand the ecological environment of Poyang Lake.The analysis results of PCA,NMDS,UPGMA and MRPP showed that the community composition of bacterioplankton bacteria in Poyang Lake was relatively close,and the community composition of bacterioplankton bacteria in the different lake regions was slightly different but not significant,and the climate became the most important factor affecting the diversity of planktonic bacterial communities.