油菜内生细菌16S核糖体DNA的RFLP分析

16S rDNA RFLP analysis of endophytic bacteria from Brassica napus

植物内生细菌定殖在植物组织内部但不引起明显的病害症状。从健康油菜植株的不同器官中分离到大量内生细菌,这些细菌菌落形态存在明显的差异,表明油菜组织中存在大量内生细菌,且类群丰富。分离到的122株内生细菌根据菌落形态可以划分为35类;利用细菌通用引物对16S核糖体DNA进行扩增,获得约1.5kb片段,分别用内切酶HaeⅢ和MspⅠ对扩增产物进行限制性酶切,产生不同的酶切图谱,根据酶切图谱聚类分析结果,所有供试菌株被归为39类,这一结果从遗传上显示油菜内生细菌类群的多样性。两种方法归类结果比较发现菌落特征所反映的信息量有限,只能作为初步的参考指标,核糖体DNA的限制性片段长度多态性分析快速、准确,可以作为油菜内生细菌多样性分析的一种有效方法。

Endophytic bacteria reside in plant hosts without causing disease symptom. In this study,122 endophytic bacteria strains isolated from healthy oilseed rape plant were categorized preliminarily to 35 groups based on colony morphology; 16S rDNAs were amplified with universal primers of bacteria, all the strains could produce a single band about 1500bp, the PCR products were digested with restriction endoenzyme HaeⅢ and MspⅠrespectively, different patterns were obtained for each enzyme, by combining all the restriction patterns for the two enzymes, the 122 strains could be grouped into 39 16S rDNA genotypes. The results indicated that endophytic bacteria from Brassica napus were genetically diversity. By comparing two methods, colony morphology only showed limited and preliminary information, and PCR-RFLP could be as a rapid and accurate tool for the diversity analysis of endophytic bacteria from Brassica napus.