Abstract: Objective: To study the fungicidal effect and influence of glow discharge plasma (GDP) on the spores of Fusarium sulphureum. Methods: The fungicidal effect of glow discharge plasma on the standard strain (BNCC 117681) of F. sulphureum was studied under different conditions. Then, Box-Behnken design was used to investigate the effects of voltage, time and inter-electrode distance as well as interactions among them on the fungicidal efficiency, and the optimum levels of these parameters were determined. Finally, the effects of glow discharge plasma on the growth, membrane integrity and peroxidative damage of the fungus were studied. The results showed that voltage, time and inter-electrode distance were the significant factors affecting the fungicidal efficiency. Under the conditions of voltage 560 V, time 15 min, and inter-electrode distance 1.5 cm, the highest fungicidal efficiency of 92.73% was obtained. After the strain was treated with glow discharge plasma, the spore germination rate, colony diameter, fungal dry mass and ergosterol concentration decreased significantly (P < 0.05); the relative conductivity, the leakage of macromolecular substances (protein and nucleic acid), the fluorescence staining intensity of propidium iodide and the concentration of malondialdehyde increased significantly (P < 0.05). The results indicated that the cell membrane was likely to be the main site for glow discharge plasma to attack F. sulphureum, causing damage to the cell membrane and consequently cell death. Conclusion: Glow discharge plasma has a significant fungicidal effect on F. sulphureum spores, which provides a theoretical basis for the application of this technique in the killing of pathogenic fungi in foods.

Key words: glow discharge plasma; Fusarium sulphureum; activity; fungicidal