Antifungal activity of camphor against four phytopathogens of Fusarium

Fusarium, one of the main fungal pathogens, can infect field crops, horticultural plants and cause great economic loss. The exploitation of effective and environmentally friendly Fusarium control agents has important application value for agricultural production. In this study, an investigation was completed on the antifungal activity of camphor against four common phytopathogens: Fusarium oxysporum G5, F. solani G9, F. verticillioide, and F. graminearum. The method adopted was mycelial growth inhibition. The minimum inhibitory concentrations (MIC) of camphor against the four tested fungi were 4.0, 4.0, 4.0, and 2.0 mg/mL, and the half maximal inhibitory concentrations (IC50) were 2.0, 2.0, 2.0, and 1.0 mg/mL, respectively. The paper proper also involves an investigation of fungicidal mechanisms via cell membrane permeability, proteins and nucleic acids leakage using colorimetry and scanning electron microscopy. The results indicated that camphor could exhibit pronounced fungicidal activities against the four tested fungi, and cytomembrane may be the target of camphor. The preliminary antifungal mechanism revealed that camphor could cause cytomembrane destruction, enhancing the permeability of cytomembrane and releasing intracellular macromolecules, such as nucleic acids and proteins. In conclusion, our results suggested that the camphor could be a promising alternative for the control of phytopathogenic Fusarium in the production of common and industrial crops.