珙桐内生细菌的分离鉴定及系统发育分析

Isolation and phylogenetic analysis of endophytic bacteria in Davidia involucrate

摘要:

用微生物学传统分离培养方法从珙桐茎、叶及叶柄中分离到内生细菌56株, 选取17株内生菌, 提取其基因组DNA, 并以此为模板, PCR扩增其16S rRNA, 扩增出约1 500 bp大小的DNA条带, 对15 株内生菌16S rRNA测序, 结果利用BLAST软件进行相似性比对, 发现11株为Bacillus属, 相似性为95%?98%; 2株为Lysinibacillus属, 相似性为97%和99%; 1株为Bordetella属, 相似性为95%; 1株为非培养细菌的同源菌, 相似性96%。芽孢杆菌为珙桐内生细菌优势菌属。通过构建系统发育树发现这15株内生菌明显聚为2大支。

Abstract:

A total of 56 endophytic bacteria were isolated from the stem, leaves and petioles of Davidia involucrate with tradational cultural methods. Of which, 17 endophytic bateria were selected to carry out succedent molecular studies. About 1 500 bp fragments of 16S rDNA were amplified by PCR method using the extracted genomic DNA as the templet. According to sequences analysis and comparison with the data of GenBank by BLAST, eleven endophytic bacreia were classed to Bacillus genera, the identities are from 95% to 98%, two were classed to Lysinibacillus genera, the identities are 97% and 99%, one were classed to Bordetella genus, the identity was 95%, and one was similar to a reported uncultured bacterium, the identity was 96%. Bacillus was the dominant genus among the endophytic bacteria in Davidia involucrate. The phylogenic tree showed that the 15 endophytic bacteria clustered two main branches.