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【目的】致病杆菌属(Xenorhabdus)细菌是一类重要的生物杀虫剂,斯氏属昆虫病原线虫的共生菌,建立快速准确的分类鉴定方法,对研究开发这类细菌至关重要。【方法】本研究PCR扩增测序了本室保藏的26株,含20种已定名致病杆菌属细菌的一段845 bp的23S rDNA序列,构建了基于这段序列的致病杆菌属系统树并与基于几乎全长16S rDNA序列的相应系统树进行比较,分析了两者作为致病杆菌属细菌分类鉴定分子标记的优缺点。【结果】结果表明,与全长16S rDNA序列相比,所选择的23S rDNA序列片段所含可变位点、简约信息位点比例更高,遗传距离数值跨度大。【结论】上述结果显示该序列片段可用于致病杆菌属细菌进行分类鉴定,特别适用于对野外资源调查中采集到的大量菌株进行快速鉴定。
【Objective】 Xenorhabdus is a kind of important biological insecticide. The symbiotic bacteria of the genus Sirius and the establishment of a rapid and accurate classification and identification method are very important for the research and development of such bacteria. 【Method】 In this study, a total of 26 strains isolated from our laboratory were sequenced, including an 845 bp 23S rDNA sequence of 20 named pathogenic Bacillus species. A phylogenetic tree based on this sequence was constructed Compared with the corresponding phylogenetic tree based on the almost full-length 16S rDNA sequence, the advantages and disadvantages of the two as molecular markers for the identification and identification of bacteria of pathogenic Bacillus were analyzed. 【Result】 The results showed that compared with the full-length 16S rDNA sequence, the selected 23S rDNA sequence fragment contained more variable sites and more parsimony informative sites with larger genetic distance span. 【Conclusion】 The above results show that the sequence fragment can be used for the identification of pathogenic Bacillus species, which is especially suitable for the rapid identification of a large number of strains collected in the field survey.