蓝桉叶片挥发物对棉铃虫产卵选择行为的影响
Effects of leaf volatiles from blue gum Eucalyptus globulus on oviposition choices of the cotton bollworm Helicoverpa armigera

为筛选棉铃虫Helicoverpa armigera的产卵驱避剂，利用顶空动态吸附法和气相色谱质谱联用技术分析其非寄主植物蓝桉Eucalyptus globulus叶片挥发物的主要成分和相对含量，通过气相色谱-触角电位联用技术研究抱卵雌蛾对蓝桉叶片挥发物的电生理反应，并测定其电生理活性组分对抱卵雌蛾产卵选择行为的影响。结果表明，蓝桉叶片挥发物中共鉴定出39种物质，以萜烯类物质为主，约占挥发物总量的97.47%，其中含量最高的4种物质为α-蒎烯、反-罗勒烯、1，8-桉叶素和柠檬烯，分别占挥发物总量的44.65%、10.55%、8.16%和7.37%。能够引起棉铃虫抱卵雌蛾电生理反应的物质有12种，分别是α-蒎烯、β-蒎烯、β-月桂烯、α-水芹烯、柠檬烯、1，8-桉叶素、反-罗勒烯、4-异丙烯基甲苯、4，8-二甲基-1，3，7-壬三烯、1，3，8-对薄荷三烯、香橙烯和α-法尼烯。α-水芹烯在0.1 μg剂量、α-蒎烯和α-法尼烯在1 μg剂量时对抱卵雌蛾均表现出显著的产卵引诱作用；柠檬烯在100 μg剂量时表现为显著的产卵驱避作用，其余剂量处理下均失去引诱或驱避效果；4-异丙烯基甲苯在1、10和100 μg剂量以及1，8-桉叶素在10 μg和100 μg剂量时均表现为显著的产卵驱避作用。表明4-异丙烯基甲苯和1，8-桉叶素可作为棉铃虫产卵驱避剂备选物质进行研究和开发。
In order to screen out oviposition repellents of the cotton bollworm, Helicoverpa armigera, the leaf volatiles from Eucalyptus globulus (non-host of cotton bollworm) were collected by dynamic headspace absorption method and were analyzed by gas chromatography-mass spectrometry (GC-MS). The electro-physiological responses of the gravid female cotton bollworm to the leaf extracts were recorded by coupled gas chromatography-electroantennogram detection (GC-EAD). Their oviposition choices for individual GC-EAD-active components were also tested. The results showed that 39 compounds were identified from E. globulus leaves. Among them, the terpenes were the dominant compounds, accounting for 97.47% of the total. Among the terpenes, α-pinene, trans-ocimene, 1,8-cineole, and limonene accounted for 44.65%, 10.55%, 8.16% and 7.37%, respectively. Twelve volatile compounds from E. globulus leaves elicited GC-EAD responses of the females, including α-pinene, β-pinene, β-myrcene, α-phellandrene, limonene, 1,8-cineole, trans-ocimene, 1-methyl-4-isop, 4,8-dimethyl-1,3,7-nonatriene (DMNT), 1,3,8-p-menthatriene, decahydro-1,1,7-trimethyl-4-alpha-methylene-1h-cycloprop[e]azulene, and α-farnesene. α-phellandrene showed significant attractant effect on their oviposition choice at the dosage of 0.1 μg, and so did α-pinene and α-farnesene at the dosage of 1 μg. Limonene respelled their oviposition at the dosage of 100 μg, and none of these four compounds showed any effect on female oviposition choice at other dosages. 1-methyl-4-isop showed significant repellent effect on the their oviposition at the dosages of 1, 10 and 100 μg, and so did 1,8-cineole at the dosages of 10 μg and 100 μg. These results indicated that 1-methyl-4-isop and 1,8-cineole were good candidates as oviposition repellents of the cotton bollworm.