Autotoxicity of Panax ginseng rhizosphere and non-rhizosphere soil extracts on early seedlings growth and identification of chemicals

Laboratory experiments were conducted to study the allelopathy of Panax ginseng growing soil extracts on the growth of its own seedlings. Soil samples were extracted with methanol. P. ginseng seeds were incubated on water-soaked filter paper in Petri dishes containing 6-concentrations (50,100,150,200,250,300 μl per petri dish) of extracts. Each treatment was replicated thrice. After incubation at 20°C in darkness for 15 days, radicle and shoot length of ginseng seedlings were measured to determine the effects of soil extracts. The methanol extract from P. ginseng rhizosphere soil inhibited the growth of P. ginseng seedlings more than extracts from non-rhizosphere soils. Furthermore, chemicals in each soil extracts were analyzed by GC-MS, and more than 30 chemicals were identified.