Abstract: In order to investigate the essential oil from Cymbopogon citratus and the antimicrobial activities of its predominant element, to provide a theoretical basis for further exploitation of plant pesticide, this paper extracted essential oil from Cymbopogon citratus by steam distillation and analyzed the component of essential oil by gas chromatography coupled with mass spectrometry (GC-MS). Total 26 components were identified representing 9357% of the essential oil，including citral (75.73%)，the most predominant compound, terpenoids having the highest relative content (93.13%). Besides, aldehyde took the highest proportion of essential oil by 76.35%, followed by alcohol, ketone, cyclic ether and ester. The bacteriostatic activities of Cymbopogon citratus essential oil and citral against 4 important pathogenic fungi from vegetables and fruits Pythium, Botrytis cinerea, Alternaria and Fusarium oxysporum were tested in vitro. The results indicated that among these 4 pathogens, both essential oil from Cymbopogon citratus and citral had the best antibacterial effect against Pythium aphanidermatum, especially the effect of citral is 35.30% higher than that of the essential oil from Cymbopogon citratus.

Key words: essential oil from Cymbopogon citratus, gas chromatography-spectrometry(GC-MS), antibacterial activity

摘要： 为了研究柠檬香茅精油及其主要成分的抑菌活性，为开发植物源农药提供理论基础，采用水蒸气蒸馏法提取柠檬香茅精油，通过气相色谱-质谱法（GC-MS）对精油进行成分分析，鉴定出了26种成分，占精油的93.57%。其中以柠檬醛（75.73%）为主，萜类化合物含量最高，可达93.13%。醛类化合物在精油中比重最高，占76.35%，其次是醇类、酮类、环醚类和酯类。采用菌丝生长法测试柠檬香茅精油及柠檬醛对黄瓜腐霉菌、番茄灰霉菌、番茄早疫病菌和辣椒尖孢镰刀菌4种重要果蔬病原真菌的抑菌活性，结果表明：在4种供试菌中，柠檬香茅精油及柠檬醛均对黄瓜腐霉病的抑菌效果最佳，但柠檬醛的抑菌效果高于柠檬香茅精油35.30%。

关键词: 柠檬香茅精油, 气相色谱-质谱（GC-MS）, 抑菌作用