To assess their potential as biopesticides, the effect on the growth of phytopathogen Fusarium oxysporum of six volatile organic compounds from endophytic fungi was studied in vivo and in vitro; compounds were used both as a mixture and individually. In vivo studies were performed inoculating the pathogen into cherry tomatoes, while the in vitro antifungal effect was studied using agar dilution and gas phase methods. Also, the morphology of the hyphae exposed to these compounds was analyzed. Moreover, the possible mechanism of action of these compounds was determined by studying the respiration and cell membrane permeability. Results show that the compounds have a significant concentration-dependent antifungal effect individually and act in a synergic manner. Additionally, changes in cell membrane permeability, damage to the hyphal morphology, and an inhibitory effect on the respiration were observed. The mixture of the six compounds may be used for postharvest control of F. oxysporum in tomatoes.
Keywords: Antifungal activity; Biopesticides; Endophytic fungi; Fusarium oxysporum; Postharvest control; Volatile organic compounds.