Abstract: In order to investigate the inhibitory effects of extracts from six plants, namely Cyperus rotundus L., Euonymus maackii Rupr., Adenophora stricta Miq., Rheum palmatum L., Cortex Fraxini, and Helianthus tuberosus L. on Fusarium moniliforme, the growth rate method was used to screen the ethanol crude extracts with strong antibacterial activity from the six plants. Then, a series of polar solvents such as petroleum ether were used to extract the screened ethanol crude plant extracts. The inhibition rate of each extract on mycelial growth was determined, the virulence differences of each extract in inhibiting mycelial growth were analyzed, the plant extract with the strongest inhibitory effect on Fusarium moniliforme was screened out, and the inhibitory effect of this plant extract on spore germination, as well as its effects on mycelial morphology and cell membrane permeability were determined. The results showed that the ethanol crude extracts of Cyperus rotundus and Euonymus maackii had significantly higher inhibitory effects on the mycelial growth of Fusarium moniliforme than the crude extracts of other plants, but there was no significant difference between them. Among the polar extraction solvents of Cyperus rotundus and Euonymus maackii, the petroleum ether extracts showed significant antibacterial activity, and the antibacterial effect of the petroleum ether extract of Cyperus rotundus was significantly higher than that of Euonymus maackii. The median inhibitory concentration (IC₅₀) of the two on mycelial growth were 6.076 6 mg/mL and 16.736 3 mg/mL, respectively. The IC₅₀ of the petroleum ether extract of Cyperus rotundus on spore germination was 7.721 7 mg/mL. This extract could lead to abnormal mycelial growth and damage the semi - permeability of the mycelial cell membrane.

Key words: plant extracts, Cyperus rotundus L., Fusarium moniliforme, inhibitory effects