ABSTRACT
Objective:To explore the composition characteristics of rhizosphere soil under <italic>Rehmannia glutinosa-Zea mays</italic> intercropping model，and screen out special signal substances in rhizosphere soil of <italic>R. glutinosa</italic> under intercropping <italic>Z. mays</italic>， so as to provide the basis for the study of allelopathic substances in continuous cropping obstacle of <italic>R. glutinosa</italic>. Method:In this experiment，rhizosphere soils of <italic>R. glutinosa</italic> under <italic>Z. mays </italic>intercropping and <italic>R. glutinosa </italic>single cropping models in July，August，September and October were taken as the research objects， and the volatile organic compounds in ethyl acetate fraction were analyzed by gas chromatography-mass spectrometry （GC-MS）. Principal component analysis （PCA）， hierachical cluster analysis （HCA） and orthogonal partial least squares discriminant analysis （OPLS-DA） analysis were performed on the data by SIMCA 14.1 to screen out potential differences in volatile organic compounds between the two models. Result:The types of volatile organic compounds in intercropping and single cropping models were mainly hydrocarbons， alcohols， esters， ketones， amides， acids and other substances. Specifically， the average relative contents of hydrocarbons，esters and amides in intercropping model were 58.46%，32.15% and 5.42% respectively，while the relative contents of hydrocarbons，esters and amides in single cropping model were 37.27%，36.11% and 21.13%. The results of PCA and HCA showed that the characteristics of volatile organic compounds in the ethyl acetate fraction of rhizosphere soil under intercropping and single cropping models could be clearly divided into two categories，the screening results of potential differential components based on OPLS-DA analysis indicated that various components， such as dibutyl phthalate，（<italic>Z</italic>）-9-oleamide，<italic>β</italic>-caryophyllene，dioctyl iso-phthalate， phthalate （2-propylamyl） diester， <italic>n</italic>-hexadecane，octodecane， <italic>n</italic>-heneicosane， were screened from rhizosphere soil under the two models. Conclusion:The <italic>R. glutinosa-Z. mays</italic> intercropping model has certain effects on the volatile organic compounds in the rhizosphere soil of <italic>R. glutinosa</italic>，and the effect of the selected components on the growth and quality characteristics of <italic>R. glutinosa</italic> still need to be further studied.