云南省田菁根瘤菌及根瘤内生细菌遗传多样性研究

本研究采用BOX-PCR指纹图谱和16SrDNA全序列分析,对45株分离自田菁的根瘤菌及根瘤内生细菌进行了菌株多样性研究,BOX-PCR指纹图谱分析结果表明,在78%的相似性水平上,待测菌株分成了4个遗传群,其中群Ⅰ和群Ⅳ分别与根癌土壤杆菌(Agrobacterium tumefaciens)和大肠杆菌(Escherichia coli)聚在一起,其它群没有与参比菌株聚群。选取每群的代表菌株进行16SrDNA全序列测定。结果表明:待测菌株归于6个属,分别是贪铜菌属(Cupriavidus)、拜纳蒙纳斯属(Balneimonas)、土壤杆菌属(Agrobacterium)、克罗诺杆菌(Cronobacter)、肠杆菌属(Enterobacter)和泛菌属(Pantoea),菌株表现了丰富的遗传多样性;其中分离自田菁的根瘤菌隶属于贪铜菌属(Cupriavidus)和拜纳蒙纳斯属(Balneimonas)尚未见其它文章报道。

Diversity of Rhizobia and Endophytic Bacteria Isolated from Root Nodules of Sesbania spp.

The diversity of 45 strains of rhizobial and endophytic bacteria isolated from root nodule of Sesbania spp. in different regions of Yunnan Province was analyzed by using BOX-PCR and full-legnth 16S rDNA sequences. The results showed that all the strains tested could be divided into four groups at a similarity level of 78%, two groups of which, Groups Ⅰ and Ⅳ, were clustered into Agrobacterium radiobacter and Escherichia coli, respectively, while the others did not cluster into the reference strains. Analysis of the full-legnth 16S rDNA sequence from the representative strains of the groups showed that these strains belonged to 6 genera, i.e. Cupriavidus, Agrobacterium, Enterobacter, Pantoea, Cronobacter and Balneomonas, and were rich in diversity, of which Cupriavidus and Balneimonas were endophytic bacteria isolated from the root nodules of Sesbania and were first reported.