Growth promotion in tomato by endophytic entomopathogenic and arbuscular mycorrhizal fungi: impacts on early development and post-transplant effect.

Tomato (Solanum lycopersicum L.) is a globally significant crop valued for its nutritional content and economic importance. This study evaluated the effect of individual and combined inoculation of two growth-promoting microorganisms in tomato: the entomopathogenic fungus Beauveria bassiana and the arbuscular mycorrhizal fungus Rhizophagus irregularis. The research was conducted in chamber conditions using tomato plants cultivar Elpida, at two developmental stages: seedlings and transplanted plants. Colonization of B. bassiana in plant tissues was confirmed by isolation from different organs, showing a higher presence in stems. mycorrhizal colonization was evident in roots, with the highest intensity in coinoculation treatments, which also showed greater formation of structures typical of symbiosis. Regarding growth, B. bassiana promoted greater leaf number and shoot biomass in seedlings, while R. irregularis favored root development, which is important for adaptation after transplanting. Coinoculation resulted in a significant increase in leaf area and mycorrhizal colonization, especially after transplanting, suggesting that the combination of these microorganisms can enhance the growth of tomato plants. The results indicate that early inoculation with B. bassiana and R. irregularis can be an effective strategy to improve plant development, although additional studies are required to evaluate long-term effects and final yield.