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

This study explored the microbial diversity within the rhizosphere of Securidaca longipedunculata (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 (p-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 Pseudomonas and Bacillus. These findings highlight the diversity of rhizospheric bacteria associated with S. longipedunculata and emphasize their role in enhancing soil fertility and plant resilience to pathogens.