Abstract: The inhibitory activity of Asarum heterotropoides essential oil extracted by steam distillation on five species of Fusarium leading to potato dry rot was tested by mycelium growth rate method and spore germination method.Steam distillation and ultrasonic-assisted extraction were utilized to optimize the extraction efficiency, and GC-MS was employed to analyze the constituents of essential oils.The results showed that the essential oil had a significant inhibitory activity on five species of tested Fusarium, which was in a dose-dependent manner with the concentration of essential oil.A total of 51 compounds were identified in essential oil by GC-MS, 18 of which were the same,while methyl eugenol and safrole were the main components in 4 groups of essential oils extracted by different methods.The content of essential oil of underground part was significantly higher than that of the aerial part and extraction rate of ultrasonic-assisted extraction method was higher.Therefore,essential oil of A.heterotropoides can be further developed as a plant derived antifungal agent with high development prospects.

Key words: Asarum heterotropoides var.mandshuricum (Maxim) kitag, essential oil, Fusarium, inhibitory activity, plant derived antifungal agent