Microbial Diversity Analysis of Soil in the Rhizosphere of Securidaca longipedunculata (African Violet Tree)

This study explored the microbial diversity within the rhizosphere of <i>Securidaca longipedunculata</i> (African violet tree), a medicinal plant recognized for its ethnobotanical importance. Six rhizospheric bacterial isolates were identified and characterized for their plant growth-promoting abilities and environmental resilience. Growth-promoting assays demonstrated that the isolates could grow in a nitrogen free environment, solubilize phosphate, produce ammonia, and synthesize indole acetic acid (IAA). Morphological and biochemical characterizations differentiated four Gram-positive from two Gram-negative strains. The bacterial isolates demonstrated plant-growth promoting potential, showing an enhanced ability (<i>p</i>-value < 0.05) to promote root elongation and biomass accumulation compared to the control treatments. The strains showed antifungal properties with some isolates recording 100% fungal mycelial growth and spore germination inhibition. Phylogenetic studies linked these isolates to the genera <i>Pseudomonas</i> and <i>Bacillus</i>. These findings highlight the diversity of rhizospheric bacteria associated with <i>S. longipedunculata</i> and emphasize their role in enhancing soil fertility and plant resilience to pathogens.