Effect of Wood Vinegar on Respiration of Plant Pathogenic Fungi

To explore practical application of wood vinegar in biological control of plant diseases and its impact on respiratory function of pathogenic fungi, experiment used mycelial growth rate method to determine its antibacterial activity against 7 plant pathogenic fungi, and studied its impact on key enzymes of tricarboxylic acid cycle and energy metabolism of sensitive strain Fusarium culmorum tested．Results showed that wood vinegar had a certain inhibitory effect on 7 kinds of plant pathogenic fungi tested, among which Fusarium culmorum, a sensitive strain, showed the most significant inhibitory effect．Its EC₅₀ value was 4.98 μL/mL, and when concentration was 5.5 μL/mL, inhibition rates of spore germination and biomass by wood vinegar were 90.09% and 95.22%, respectively．After wood vinegar treatment, respiration rate of Fusarium culmorum was inhibited, activities of SDH and MDH decreased, content of ATP decreased, ADP and AMP increased first and then decreased, and energy charge level decreased, indicating that wood vinegar inhibited respiration and metabolism of Fusarium culmorum．It hindered normal operation of tricarboxylic acid cycle, interfered with its energy metabolism, and led to dysfunction of fungal somatic cells．It has been preliminarily proved that wood vinegar ccould achieve its antifungal effect mainly by destroying respiration and metabolism of fungi．