Rhizosphere bacteria with an antifungal potential against maize phytopathogens. (Abstr.) Phytopathology

BIGATTÓN E.; AYOUD I.; VAZQUEZ C.; BERDINI A.; ARCHILLA M.; BRUNO M.; DUBINI L.; PIZZOLITTO R.; MORENO V; PRIETO M.; MERLO C.; LUCINI E.

Congreso; 5° Congreso Argentino de Fitopatología. 59° Meeting of the APS Caribbean Division; 2023

Rhizobacteria of the Bacillus genus can produce volatile organic compounds (VOCs) with the ability to reduce fungal growth andsporulation. The objective was to study the bio-controller effect of Bacillus against maize (Zea mays) phytopathogenic fungi. From thesoil rhizosphere of Córdoba agricultural fields (Argentina), 40 bacterial strains were isolated and genetically identified. To evaluateantifungal activity a suspension of each bacterial strain was inoculated onto a Petri plate with nutritive agar and incubated at 28°C for 24h. Subsequently, a conidial suspension (of Fusarium verticillioides and Aspergillus flavus) was added at the center of the plate withPDA. Then, plates with bacteria and conidia were faced and sealed and cultivated at 28°C for 7 days. The radial mycelial growth wasS1.14determined by periodical measurement and growth inhibition percentage was calculated. Of the total of the isolated strains, 18inhibited mycelial growth. The highest percentages were detected for the VOCs emitted by the strains of B. velezensis (RI1, RI2, andSI3), B. altitunidis (SI2), and B. tequilensis (SC1), which could inhibit 47%–55% of A. flavus growth. The strains showed lesscapacity of inhibiting F. verticillioides growth. In conclusion, bacterial VOCs showed a bio-controlling effect, being higher against A.flavus. Future studies should be carried out to elucidate the action mechanisms of VOCs produced by bacteria, for bio-inputsformulation