Antifungal activity of Mikania micrantha against Magnaporthe oxyzae

Objective Mikania micrantha, an invasive species, was used as a material to investigate the antifungal activity of its different extracts and components against Magnaporthe oxyzae.

Method The antifungal activity of extract of M. micrantha from Dehong, Yunnan Province was determined by growth rate method with M. oxyzae as the test pathogen, and the antifungal active components of the extract were traced by column chromatography.

Result At the initial screening concentration of 1 mg/mL, M. micrantha ethylacetate extract showed potent antifungal activity against M. oxyzae, with an inhibition rate of 49.84%. The antifungal activity tracking of 14 column chromatography fractions of the ethylacetate extract showed that the antifungal activity of Fr₅, Fr₆, Fr₁₂ and Fr₁₃ was significant, EC₅₀ values were 1.856, 1.846, 0.634 and 0.29 mg/mL, respectively. All the four active components resulted in the reduction of mycelial mass, elevation of MDA content, aberration of mycelial morphology, and reduction of spore number of M. oxyzae.

Conclusion This study finds that M. micrantha can significantly inhibit M. oxyzae, which provides a new idea for comprehensive development and utilization of M. micrantha, and also provides a scientific basis for green control of M. oxyzae.