Abstract: The relationship between Fusarium oxysporum and mass ratio  of  ginsenoside in ginseng root was investigated. In order to determine the effect of ginsen root inoculated with Fusarium oxysporum on the mass ratio of ginsenoside, the  change of mass ratio of three ginsenosides Rb1,Re and Rg1 within 120 h after inoculation with Fusarium oxysporum was monitored  by high performance liquid chromatography (HPLC). The results show that after Fusarium oxysporum infection, the mass ratio  of Rb1 increases, and  the mass ratio of Re and Rg1 does not change significantly.  Rb1 has obviously inhibitory effect on conidia of Fusarium oxysporum, the higher the mass concentration of Rb1, the lower the germination rate  and the higher the inhibition rate.  Re and Rg1 have almost no inhibitory effect on conidia of Fusarium oxysporum. Therefore, Rb1 may be a disease-resistant compound produced by ginseng roots against Fusarium oxysporum.

Key words: ginsenoside, ginseng, chemical response, Fusarium oxysporum