不同生长年限桔梗根部内生细菌种群结构分析  

Population structure analysis of endophytic bacteria in roots of Platycodon grandiflorum(Jacq)A.DC with different growth years

作　　者：宋旭红[1] 李隆云[1] 崔广林[1] 丁刚[1] SONG Xu-hong;LI Long-yun;CUI Guang-lin;DING Gang(Chongqing Academy of Chinese Materia Medica/Chongqing Engineering Research Center for Fine Variety Breeding Techniques of Chinese Materia Medica/Chongqing Sub-center of National Resource Center for Chinese Materia Medica,China Academy of Chinese Medical Science,Chongqing 400065,China)

机构地区：[1]重庆市中药研究院/重庆市中药良种选育与评价工程技术研究中心/中国中医科学院中药资源中心重庆分中心,重庆400065

出　　处：《南方农业学报》2020年第10期2358-2366,共9页Journal of Southern Agriculture

基　　金：国家中药材产业技术体系建设专项(CARS-21);重庆市现代山地特色高效农业技术体系建设专项(2019〔5〕号)。

摘　　要：【目的】分析不同生长年限桔梗根部内生细菌种群结构及多样性,为深入理解植物—微生物互作和挖掘可培养细菌资源,建立功能细菌资源库提供理论支持。【方法】采用Illumina MiSeq高通量测序技术,对1~3年生桔梗根部内生细菌的16S rDNA V3~V4区进行PCR扩增,对PCR产物进行高通量测序。使用QIIME软件统计不同样本的群落丰富度(Chao1指数和ACE指数)及多样性(Shannon指数和Simpson指数),运用R软件计算各样本共有OTU数量,并通过Venn图呈现各样本共有和独有OTU数量。同时,借用热图和LEfSe进行不同样本间的差异显著单元分析,共同阐述不同生长年限桔梗根部内生细菌种群的多样性变化规律。【结果】不同生长年限桔梗根部内生细菌种群结构及多样性存在一定差异。随着生长年限的增加,桔梗根部内生细菌的丰富度及群落多样性持续降低,桔梗根部内生细菌特有的OTU数量持续减少。1~2年生样本的优势菌群为变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)、蓝细菌门(Cyanobacteria)和放线菌门(Actinobacteria),3年生桔梗根部以变形菌门、厚壁菌门、蓝细菌门和栖热链球菌门(Deinococcus-Thermus)为优势菌群。变形菌门的相对丰度在3个样本中最高,分别为76.35%、82.38%和86.46%。1年生桔梗根部内生细菌中变形菌门的相对丰度显著低于2年生和3年生样本(P<0.05),2年生与3年生桔梗样本间差异不显著(P>0.05)。芽孢杆菌属(Bacillus)、慢生根瘤菌属(Bradyrhizobium)及Dyella的相对丰度在1年生桔梗中最高,假单胞菌属(Pseudomonas)的相对丰度在3年生桔梗样本中最高。【结论】桔梗根部内生细菌具有丰富的多样性,不同生长年限桔梗根部内生细菌的群落结构不同,随着生长年限的增加,桔梗内生细菌的特有OTU、丰富度和群落多样性持续降低。生长年限是造成桔梗内生细菌种群结构及多样性变化的因素之一。芽孢杆菌属、【Objective】In order to provide theoretical support for further understanding of plant microorganism interaction,mining culturable bacterial resources,and establishing functional bacterial resource,the population structure and diversity of endophytic bacteria in the roots of Platycodon grandiflorum(Jacq.)A.DC with different growth years were analyzed.【Method】The 16S rDNA sequence V3-V5 region of bacteria was amplified by PCR,and then the products of PCR amplification were sequenced with high throughput based on Illumina MiSeq platform.The community richness(Chao1 index and ACE index)and diversity(Shannon index and Simpson index)were calculated by QIIME software.R software was used to calculate the number of OTUs shared in each sample,and the number of OTUs shared and unique in each sample was showed through Venn diagram.Meanwhile,heat map and LEfSe statistical analysis were also used to estimate the diversity of endophytic bacteria population in roots of P.grandiflorum in different growth years.【Result】There were some differences in population structure and diversity of endophytic bacteria in root of P.grandiflorum with different growth years.With the increase of growth years,the richness of endophytic bacteria and the diversity of community in the roots of P.grandiflorum continued to decrease.The number of unique OTUs was decreased continuously.The results showed that Proteobacteria,Firmicutes,Cyanobacteria and Actinobacteria were the dominant microflora in 1-year-old to 2-year-old samples,while Proteobacteria,Firmicutes,Cyanobacteria and Deinococcus-Thermus were the dominant microflora in 3-year-old sample.The relative abundance of Proteobacteria was the highest in the three samples,76.35%,82.38%and 86.46%respectively.The relative abundance of Proteobacteria in root of 1-year-old was significantly lower than that of 2-year and 3-year-old samples(P<0.05),but there was no significant difference between 2-year-old and 3-year-old samples(P>0.05).The relative abundances of Bacillus,Bradyrhizobium and Dyel

关 键 词：桔梗 内生细菌 Illumina MiSeq高通量测序 群落组成 多样性变化 

分 类 号：S182[农业科学—农业基础科学]