不同农田生境对通俗腔蚓肠道菌群结构的影响

Comparison of Intestinal Bacteria Structure of Metaphire vulgaris from Different Habitats

【目的】蚯蚓肠道微生物种类繁多,其中细菌群落对蚯蚓适应不同的生境具有重要作用,而关于蚯蚓肠道菌群的研究多集中于养殖型蚯蚓,野生蚯蚓的研究相对缺乏。【方法】为解析不同生境野生蚯蚓肠道的菌群差异,本研究采集河北省沧州市农林科学院试验田中的黄瓜地和辣椒地的通俗腔蚓(Metaphire vulgaris),并通过高通量测序对其肠道细菌群落进行了分析。提取蚯蚓肠道微生物总DNA,特异性扩增16S rRNA基因的V3-V4区,利用Illumina Hiseq 2500测序平台进行双端测序,然后对OTU(operational taxonomic unit)归类,并进行物种组成分析、Alpha和Beta多样性分析、样品组间统计分析。【结果】蚯蚓肠道分离土样中CZM(采自辣椒地的蚯蚓)和CZH(采自黄瓜地的蚯蚓)相对丰度大于1%的优势菌属分别为12和13个,肠道细菌中门水平相对丰度最高的是变形菌(Proteobacteria)。同时,还发现一些未分类的细菌,CZH肠道菌群中未分类的细菌较多,且CZH肠道细菌多样性指数也高于CZM。此外,CZH和CZM肠道细菌中丰富度位于前30且有属类分析的OTU代表性序列在系统发育树中位置不同。【结论】在种植不同蔬菜的土壤环境中生存的同种蚯蚓肠道微生物存在差异,取自黄瓜地的蚯蚓肠道细菌多样性指数均显著高于取自辣椒地的样品,表明黄瓜地土壤更有利于蚯蚓形成丰富且稳定的肠道微生物菌群。

[Objective]Various intestinal microorganisms have been found in earthworms,among which the bacterial community plays an important role for earthworms to adapt to different habitats.However,the research on the intestinal flora of earthworms mostly focuses on cultured earthworms.This research will be on wild earthworms.[Method]Metaphire vulgaris in cucumber and pepper field at Cangzhou Academy of Agricultural Sciences in Hebei Province were collected in order to analyze the differences of the intestinal flora of wild earthworms in different habitats,and their intestinal bacterial communities were analyzed by high-throughput sequencing.The total DNA of earthworm intestinal microorganisms was extracted,the V3-V4 region of 16S rRNA Gene was specifically amplified,and the two terminal sequencings was carried out by Illumina hiseq2500 sequencing platform.Then OTU(operational taxonomic unit)was classified.The species composition analysis,Alpha and Beta diversity analysis,and inter-sample group statistical analysis were carried out.[Result]The results showed that the dominant bacteria with relative abundance greater than 1%of CZM(earthworm from pepper field)and CZH(earthworm from cucumber field)were 12 and 13.Proteobacteria is the bacterium Phylum with the highest relative abundance of gut microbes.At the same time,some unclassified bacteria were also found,and there were more unclassified bacteria in CZH than CZM.In addition,the abundance of CZH and CZM intestinal bacteria with richness in the top 30 had different positions on the phylogenetic tree.[Conclusion]This study showed that there were differences in intestinal microorganisms of the same earthworm species living in different vegetable environments,which will provide a reference for understanding the intestinal bacterial community composition of wild-type earthworm species.