Characterisation and Biodiversity of a Fast-Growing Rhizobacterial Population Nodulating Lupine in Morocco

El Hilali I., J. El Jamali, I. Thami Alami, A. Filali Maltouf

First investigation was made to assess the phenotypic and the genetic diversity of nodule occupants harvested from different lupine species in Morocco. The determination of the phenotypic characteristics of strains revealed a wide range of tolerance to pH, to high salt (NaCl) concentrations and to extreme temperatures. Strains were also highly resistant to many heavy metals and antibiotics. Particularly, strains exhibited a fast growth rate and cultural features typical to Rhizobium. Besides, symbiosis with Lupinus luteus showed to be more effective with strains isolated from wild species. Numerical analysis allowed the recovery of interesting strains for use as potential inoculants. PCR-RFLP patterns of 16S rRNA gene indicate a big heterogeneity between the strains with a clear distinction from the reference strains used. However, two strains were closely related to Rhizobium and another strain was grouped with the Mesorhizobium. Further analysis to precise the taxonomic position of these strains is claimed.