Abstract: There is a daily change of plant volatile matter. It is very important to study the disturbance of light condition on volatile matter releasing of plants in a day to find out the regulation mechanism of circadian rhythm on volatile matter released by plants. In this study,the cuttage of Thymus mongolicus was used as the experimental material. The species and content of volatile substances were determined by HS-SPME/ GC-MS. Two treatments were performed in the experiment. The experimental group was treated with darkness,and the control group was given normal light. The sampling time was at six time points (0:00;4:00;8:00;12:00;16:00;20:00) in a day. The results showed that the volatile compounds released from thymus were mainly alkenes,aromatic hydrocarbons,alcohols,phenols and esters. The amount and relative content of olefins were the most. Under normal light,80 kinds of volatiles were detected,with the peak at 8:00 and the low at 12:00 and 0:00. In the dark treatment group,77 species were detected,with the least number at 16:00 and the most at 20:00. Dark treatment affected the diurnal variation trend of the relative content of various kinds of volatiles,and reduced the fluctuation range of the relative content of volatile compounds. The variation range of olefins,aromatic hydrocarbons and alcohols were 41.57%,61.03% and 42.87% of the light treatment group,respectively. The experiment provides an evidence for exploring the release mechanism of plant volatiles.

Key words: Thymus mongolicus, Volatile components, Darkness treatment, Diurnal variation

摘要： 为研究黑暗处理对植物挥发物释放日变化节律的影响，本试验采用顶空固相微萃取结合气质联用法（HS-SPME/GC-MS），在1天中6个时间点对正常光照和黑暗处理下的百里香（Thymus mongolicus）叶片释放的挥发性有机物进行测定。研究表明：百里香释放的挥发性物质主要为烯烃类、芳香烃类、醇类、酚类和酯类，其中烯烃类挥发物的数量与相对含量均最多。正常光照下共检测出80种挥发物，8：00为挥发高峰期，12：00和0：00为挥发低谷期。黑暗处理组中共检测出77种，16：00数量最少，20：00数量最多。黑暗处理影响了各类挥发物相对含量日变化趋势，并且减小挥发物相对含量日变化波动幅度，其中烯烃类、芳香烃类、醇类挥发物的变化范围分别为正常光照的41.57%，61.03%，42.87%。本试验为进一步探明植物挥发物释放机理提供了试验证据。

关键词: 百里香, 挥发性成分, 黑暗处理, 日变化