Bio - priming and Antagonistic Potentials of Senna obtusifolia Endophytic Bacteria

Abstract

Endophytic microorganisms have continued to gain prominence as rich sources of useful compounds such as plant growth-promoting chemicals, bioactive compounds, among others. The present study aimed at evaluating the tomato seeds bio-priming and antagonistic potentials of endophytic bacteria isolated from Senna obtusifolia. Endophytic bacteria harbored in the roots and leaves of S. obtusifolia were isolated using a combination of cultural, biochemical, and microscopic techniques. The isolates were evaluated for possible applications as growth-promoting agents of tomato seeds and also, as antagonistic agents to the notorious plant pathogenic fungus Fusarium oxysporum. Diverse genera of bacteria were isolated from the plant, and these prominently include Bacillus spp; Staphylococcus aureus; Escherichia coli; Enterobacter spp; Rhizobium spp and Pseudomonas spp. Although tomato seeds bio-primed with Enterobacter spp germinated before all others, the germination period (4 days) was statistically the same (P< 0.05) as that yielded by the control (4.5). Similarly, tomato seeds treated with S. aureus yielded the highest number of leaves (2.5), and this was also statistically the same as that yielded by the control (P < 0.05). All the isolates used in the evaluation of antagonistic activity yielded significantly larger (P > 0.05) zones of inhibition than the control (11.0 mm). Among these, Bacillus spp yielded the largest zone (21.6 mm). The study revealed that S. obtusifolia harbors endophytic bacteria that could inhibit the growth of the plant pathogen, F. oxysporum.