Laboratoire de Biologie des Plantes et des Microorganismes, Faculty of Sciences, Mohamed Premier University, Oujda, Morocco.
Arch Microbiol. 2011 Feb;193(2):115-24. doi: 10.1007/s00203-010-0650-0. Epub 2010 Nov 17.
Eighteen isolates of rhizobia isolated from root nodules of Colutea arborescens (Bladder senna) grown in different soils of the eastern area of Morocco were characterized by phenotypic and genomic analyses. All the isolates characterized were fast growers. This is may be due to the isolation procedures used. The phenotypic, symbiotic and cultural characteristics analyzed allowed the description of a wide physiological diversity among tested isolates. The results obtained suggest that the phenotype of these rhizobia might have convergent evolved to adapt the local conditions. The genetic characterization consisted in an analysis of the rep-PCR fingerprints and the PCR-based RFLP of the 16S rDNA patterns. The 16S rDNA of six isolates representing the main ribotypes obtained by the PCR-based RFLP was sequenced. A large diversity was observed among these rhizobia, and they were classified as different species of the genera Rhizobium, Sinorhizobium and Mesorhizobium. The nodC gene was also sequenced, and the results confirmed the three lineages corresponding to the three genera. The results of the sequencing of nodC and 16S rDNA genes suggest that the nodulation genes and chromosome might have co-evolved among these bacteria.
从摩洛哥东部不同土壤中生长的灌木黄耆（膀胱豆）根瘤中分离出的 18 株根瘤菌，通过表型和基因组分析进行了特征描述。所有鉴定出的菌株均为快速生长菌。这可能是由于所采用的分离程序。分析的表型、共生和文化特征允许描述测试菌株之间广泛的生理多样性。研究结果表明，这些根瘤菌的表型可能已经趋同进化以适应当地条件。遗传特征包括重复扩增 PCR 指纹图谱分析和基于 PCR 的 16S rDNA 模式 RFLP 分析。代表基于 PCR 的 RFLP 获得的主要核糖体类型的六个分离株的 16S rDNA 进行了测序。观察到这些根瘤菌之间存在很大的多样性，它们被分类为根瘤菌属、中华根瘤菌属和中慢生根瘤菌属的不同种。nodC 基因也进行了测序，结果证实了对应于三个属的三个谱系。nodC 和 16S rDNA 基因的测序结果表明，这些细菌中的共生基因和染色体可能已经共同进化。
