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Atractylodes lancea is one of widely used medicinal herbs in oriental societies.However current practice of continuous cropping of this plant leads to a dramatic lose of production.The aim of this study was to investigate the potential allelochemical autotoxicity involving continuous cropping.Rhizome and rhizosphere soil extracts were collected from 8-month old Atractylodes lancea plants grown in a glasshouse to examine their bioactivity and allelopathic compounds.An in vitro experiment was established to test the autotoxicity of rhizome extracts and rhizosphere extracts on early development of A.lancea.The results showed a general increasing trend of inhibitory effect on seed germination and early development of A.lancea plants with the increase of concentration of extracts.The development of radicles and embryos of seeds treated with higher concentrations of either rhizosphere soil extract (500 mg ml-1) or rhizome extract (200 mg ml-1) were substantially inhibited.A total of 20 compounds were identified from rhizome extracts and 27 compounds from rhizosphere soil extracts by GC-MS.Some phytotoxic compounds,including 2,5-octadecadlynoic acid,methyl ester,n-hexadecanoic acid,pentadecanal,tetradecanoic acid,1-naphthalenol,butylated hydroxytoluene,2-methoxy-4-vinylphenol,were detected in both extracts.The similarities of compounds between rhizome and rhizosphere soil extracts were evaluated by Jaccard coefficient,which ranged from 33% when extracted by diethyl ether to 90% when extracted by ethyl acetate.β-eudesmol and hinesol,which were the main components of naphtha in A.lancea,were found in rhizome extracts.A following up in vitro experiment was then conducted under controlled conditions to examine the autotoxicity of β-eudesmol,which showed the significantly inhibited development of embryo of A.lancea seeds treated with two higher rates of β-eudesmol (100 and 250 mg l-1).This result confirmed the autotoxicity of β-eudesmol and rhizome extracts accordingly.Through well-designed experiments and biochemistry analyses,this study demonstrated the presence of allelochemical autotoxicity during the cultivation of A.lancea.Findings from this research may enhance understanding of the impediments during continuous cropping of A.lancea and other relevant medicinal plants.