Centre de Biotechnologies Végétale et Microbienne, Biodiversité et Environnement, Faculté des Sciences, Université Mohammed V de Rabat, 4, Avenue Ibn Battouta, Rabat, Morocco.
Centre de Recherche Forestière, Département des Eaux et Forêts, Avenue Omar Ibn El Khattab, BP 763, Rabat-Agdal 10050, Morocco.
Syst Appl Microbiol. 2021 May;44(3):126197. doi: 10.1016/j.syapm.2021.126197. Epub 2021 Mar 26.
Out of 54 isolates from root nodules of the Moroccan-endemic Chamaecytisus albidus plants growing in soils from the Maamora cork oak forest, 44 isolates formed nodules when used to infect their original host plant. A phenotypic analysis showed the metabolic diversity of the strains that used different carbohydrates and amino acids as sole carbon and nitrogen sources. The isolates grew on media with pH values ranging from 6 to 8. However, they did not tolerate high temperatures or drought and they did not grow on media with salt concentrations higher than 85 mM. REP-PCR fingerprinting grouped the strains into 12 clusters, of which representative strains were selected for ARDRA and rrs analyses. The rrs gene sequence analysis indicated that all 12 strains were members of the genus Bradyrhizobium and their phylogeny showed that they were grouped into two different clusters. Two strains from each group were selected for multilocus sequence analysis (MLSA) using atpD, recA, gyrB and glnII housekeeping genes. The inferred phylogenetic trees confirmed that the strains clustered into two divergent clusters. Strains CM55 and CM57 were affiliated to the B. canariense/B. lupini group, whereas strains CM61 and CM64 were regrouped within the B. cytisi/B. rifense lineage. The analysis of the nodC symbiotic gene affiliated the strains to the symbiovar genistearum. The strains were also able to nodulate Retama monosperma, Lupinus luteus and Cytisus monspessulanus, but not Phaseolus vulgaris or Glycine max. Inoculation tests with C. albidus showed that some strains could be exploited as efficient inocula that could be used to improve plant growth in the Maamora forest.
从生长在马穆拉软木森林土壤中的摩洛哥特有白车轴草根瘤中分离出的 54 株菌株，其中 44 株在感染其原宿主植物时形成了根瘤。表型分析显示，利用不同碳水化合物和氨基酸作为唯一碳源和氮源的菌株具有代谢多样性。这些菌株在 pH 值为 6 到 8 的培养基中生长。然而，它们不能耐受高温或干旱，也不能在盐浓度高于 85mM 的培养基中生长。REP-PCR 指纹图谱将这些菌株分为 12 个聚类，其中选择代表性菌株进行 ARDRA 和 rrs 分析。rrs 基因序列分析表明，这 12 株菌均属于慢生根瘤菌属，它们的系统发育表明它们分为两个不同的聚类。从每个组中选择两个菌株进行多基因序列分析（MLSA），使用 atpD、recA、gyrB 和 glnII 看家基因。推断的系统发育树证实，这些菌株聚类为两个不同的分支。菌株 CM55 和 CM57 与 B. canariense/B. lupini 群相关，而菌株 CM61 和 CM64 则重新分组在 B. cytisi/B. rifense 谱系内。nodC 共生基因分析将这些菌株归类为 symbiovar genistearum。这些菌株还能够结瘤金雀儿、羽扇豆和滨黎豆，但不能结瘤菜豆或大豆。对 C. albidus 的接种试验表明，一些菌株可以被开发为有效的接种剂，可用于改善马穆拉森林中植物的生长。
