Isolation of Fusarium verticillioides and evaluation of native rhizobacteria for its control in maize

Abstract

Objective: To isolate and identify phytopathogenic fungi associated with maize cultivation and to evaluate in vitro the antagonistic potential of native rhizobacteria against F. verticillioides. Design/methodology/approach: Phytopathogens were isolated from maize plants exhibiting symptoms of root and stem rot. Their identification was carried out based on morphological characteristics and molecular analyses. In addition, seven native rhizobacterial isolates (CB1-CB7) were obtained, and their antagonistic activity against Fusarium strains was determined through in vitro dual-culture assays. Results: The two phytopathogenic strains, FMT08 and FMR13, were identified as F. verticillioides and exhibited pathogenic capacity by reducing seed germination and causing root rot. All evaluated rhizobacteria showed inhibitory activity; however, CB4 displayed the most consistent antagonistic effect against both strains, with biological effectiveness values of 53.75% for strain FMT08 and 52.50% for strain FMR13. Limitations of the study/implications: The native rhizobacterium CB4 evaluated in this study demonstrated the ability to suppress the development of F. verticillioides. As a prospective line of research, further studies are required to determine whether this effect is associated with the synthesis of antifungal compounds or with other mechanisms of action. Findings/conclusions: Two phytopathogenic maize strains identified as F. verticillioides and seven native rhizobacterial isolates from Sinaloa were obtained. Among them, CB4 stood out for its stable antagonistic activity against both pathogen strains, positioning it as a promising candidate for biocontrol strategies in maize cultivation.