Biodiversity of symbiotic microbes in association with Sulla aculeata spp. from semi-arid regions of Morocco

Abstract

Twenty-six root nodule bacteria from two native forage legumes namely Sulla aculeolata subsp. aculeolata and Sulla aculeolata subsp. mauritanica were isolated and analyzed using a polyphasic approach comprising phenotypic traits, ERIC-PCR, and 16S rRNA gene sequencing. This is the first time a study has been performed to determine the diversity of bacteria associated with Sulla aculeolata spp. Phenotypically, all the isolates were identified as fast-growing bacteria and shows high tolerance toward various stressed conditions, particularly those derived from S. aculeolata subsp. mauritanica. On the other hand, the genotypic characterization revealed high diversity among the isolated bacteria and clustered into 14 clusters at the similarity index of 90% based on ERIC-PCR analysis. Furthermore, the 16S rRNA gene sequencing of representatives strains indicates that all the strains share 99 to 100% identity with bacteria belonging to Pseudomonas, Enterobacter, Serratia, and Paenibacillus genera with a clear relation to their host plant. In conclusion, the findings of the present study suggested the inoculation of plants with appropriate bacteria to enhance plant growth and quality of Sulla aculeolata under semi-arid conditions of the Mediterranean area.