National Natural Science Foundation of China
圆柏大痣小蜂(Megastigmus sabinae Xu et He)是我国甘肃、青海和西藏等地祁连圆柏(Sabina przewalskii)球果的重要害虫,其危害严重影响了祁连圆柏的种子生产和育苗。为了筛选和鉴定圆柏大痣小蜂寄主定位相关的化学活性物质,利用动态顶空采集法和气相色谱-质谱联用技术(GC-MS,Gas Chromatograph-Mass Spectrometer)分析了祁连圆柏不同状态的球果和枝叶共5类挥发物样品成分,采用气相色谱-触角电位联用技术(GC-EAD,Gas Chromatography-Electroantennagram Detection)测定圆柏大痣小蜂对寄主挥发物的触角电位反应,利用Y型嗅觉仪测定圆柏大痣小蜂成虫对几种化学活性物质的行为反应。研究结果表明:5类挥发物中共鉴定到117种化合物,每类样品都含特有的植物挥发性成分,但其主要成分基本相似;有15种化合物能引起圆柏大痣小蜂的触角电位反应;圆柏大痣小蜂对其中的12种挥发物具有明显的趋向行为反应。3种共有成分月桂烯、桧烯和右旋萜二烯均对圆柏大痣小蜂具有吸引作用,一年生未产卵球果挥发物特有成分α-松油醇能显著吸引圆柏大痣小蜂雌成虫。由此推测月桂烯、桧烯和右旋萜二烯3种共有成分可能是圆柏大痣小蜂寄主定位时起关键作用的化合物,α-松油醇可能是圆柏大痣小蜂识别未产卵球果进行产卵定位的关键化合物。
Megastigmus Sabinae (Xu et He) is an important pest of Sabina przewalskii cone in Gansu, Qinghai and Tibet in China, which seriously affects the seed production and seedling of Sabina Przewalskii. In this study, the dynamic headspace collection and gas chromatograph-mass spectrometry (GC-MS) were used to screen and identify the potentially chemical reactive substances in host localization and oviposition localization of M. Sabinae. The composition and relative contents of 5 volatiles samples from branches and cones in different states of Sabina Przewalskii were analyzed. Gas Chromatography-Electroantennagram Detection (GC-EAD) was used to test the EAD of M. Sabinae collected volatiles in each sample. Y-typed olfactometer was used to test the behavioral responses of adults of M. Sabinae to the chemical active substances. A total of 117 compounds were identified in the 5 samples. The main components in the 5 samples were similar but each sample contained unique components. Fifteen chemical active substances could trigger the EAD reaction of M. Sabinae, of which 12 chemical active substances had significant tendency behavior response. The three shared components, sabinene, myrcene and d-Limonene, could obviously attract the female adults of M. Sabinae, while α-terpineol, the unique component in the volatile of 1-year healthy cones, could attract the female adults of M. Sabinae significantly. It is hypothesized that three compounds, sabinene, myrcene and d-Limonene, may be the key active substances in the host location and α-terpineol may be the key compound to recognize the unoviposit healthy cones of Sabina Przewalskii for oviposition localization for M. Sabinae.