ABSTRACT
Objective: To explore the relationship between continuous cropping obstacle and autotoxicity of Angelica sinensis, autotoxic effect and organic compounds of rhizosphere soil water extract were determined. Methods: Distilled water (CK), water extract of rhizosphere soil (100, 125, 250, and 500 mg/ mL) were applied to testing their effect on early development of A. sinensis. Seed germination rate, germination index, elongation of radicle and embryo were recorded, and GC-MS was conducted for the compound identification in the extract. Results: The water extract at concentraion as low as 125 mg/mL significantly inhibited the germination and seedling growth of A. sinensis, and this inhibitory effect generally increased with the increase of the concentration of water extracts. Seventeen compounds in rhizosphere soil water extract were identified, including organic acids, ketones, aldehydes, esters, and hydrocarbons, most of them are allelophathic substance. Conclusion: Water extracts from A. sinensis rhizosphere soil have inhibitory effects on A. sinensis germination and seedling growth, and this inhibitory effect generally increased with the increases of the water extract concentration at a certain ranges. In conclusion, there is autotoxicity in continuous cropping of A. sinensis, which is one of the causes of problems associated with the continuous cropping obstacle of a single plant species.