羽毛针禾内生细菌分离鉴定及系统发育树分析

Isolation,Identification and Phylogenetic Tree Analysis of Endophytic Bacteria FromStipagrostis pennata

以羽毛针禾根和种子组织为试材,采用传统培养方法和免培养方法研究了组织中分离纯化出的内生细菌,对分离得到的纯菌株进行形态学观察、生理生化鉴定,并结合菌株的16S rRNA基因序列在RDP在线数据库中鉴定其属水平。将测序结果与GenBank中已知序列进行BLAST比对,查找相似性最高的菌种序列进行同源性分析,再通过软件MEGA 7.0构建系统发育树确定菌株的系统分类学地位。结果表明:从羽毛针禾种子和根中分别分离鉴定出4株和7株内生细菌,初步将这些细菌归为2门2纲2目2科2属,种子和根中的优势属分别为泛生菌属和假单胞菌属。在羽毛针禾根和种子中的内生细菌群落结构具有较为丰富的种群多样性,且菌群优势度存在差异。该研究成果为羽毛针禾内生菌资源库信息的积累和羽毛针禾内生微生物的后续开发提供了有利指导和参考依据。

In this study,the endophytic bacteria Stipagrostispennataisolated and purified from the tissues were studied by using traditional methods and culture-free methods.The morphological observation,physiological and biochemical identification of the isolated pure strains were carried out.The 16S rRNA gene sequence of the combined strain was identified in the RDP online database.The sequencing results were compared with the known sequences in GenBank,and the sequence of the most similar strains was searched for homology analysis,and then constructed phylogenetic tree by software MEGA 7.0 to determine the systematic taxonomic status of the strain.The results showed that 4 strains and 7 endophytic bacteria were isolated from the seeds and roots of the Stipagrostis pennata,and the bacteria were classified into 2 families,2 classes,2 orders,2 families and 2 genera,and the dominant species in seeds and roots.They were the genus Pantoea and Pseudomonas.The study showed that the endophytic bacterial community structure in the roots and seeds had rich population diversity,and the dominant degree of the flora was different.The research results provided favorable guidance and scientific basis for the accumulation of information on the endophytic resources of the Stipagrostis pennata and the subsequent development of the microbes.