桉蝙蛾幼虫对桉树树干及其林下浅层土壤挥发物的嗅觉行为反应

Olfactory responses of Endoclita signifer Walker larvae to volatiles of eucalyptus trunks and shallow soil under eucalyptus forest

  • 摘要: 【目的】通过比较健康和受桉蝙蛾幼虫危害的桉树树干及其林下浅层土壤挥发物的组成与含量,探究桉蝙蛾幼虫由地栖环境向树栖危害的转移机制,为其生态防治提供理论依据。【方法】采用动态顶空吸附法提取健康和受桉蝙蛾幼虫危害桉树树干及其林下浅层土壤挥发物,利用气相色谱—质谱联用仪(GC-MS)测定挥发物的组分及含量,通过随机森林算法分析,选择5种挥发物用于测定桉蝙蛾幼虫的嗅觉行为反应。【结果】从健康和受害桉树树干及浅层土壤中分别鉴定出17、47和23种挥发物。随机森林分析结果显示,健康与受害树干挥发物的比较中,左旋-β-蒎烯、3,3-二甲基-6-亚甲基环己烯和左旋-α-蒎烯的重要性较高;桉树树干(健康及受害)与浅层土壤挥发物的比较中,左旋-β-蒎烯、莰烯、桉叶油醇、邻伞花烃、3,3-二甲基-6-亚甲基环己烯和左旋-α-蒎烯的重要性较高。行为测定结果显示,莰烯和邻伞花烃(浓度10 mg/mL)分别对桉蝙蛾3龄幼虫具有显著(P<0.05)和极显著(P<0.01)的引诱作用。【结论】桉树树干挥发物中的邻伞花烃和莰烯均可显著吸引桉蝙蛾3龄幼虫,且均在受害桉树树干挥发物中含量更高,推测二者对桉蝙蛾幼虫寻找寄主植物的行为具有调控作用。

     

    Abstract: 【Objective】By comparing composition and content of volatiles from healthy and Endoclita signifer Walkerdamaged eucalyptus trunks and shallow soil under eucalyptus forest, to study transfer mechanism on how terrestrial E. signifer larvae caused arboreal harm, so as to provide a theoretical basis prevention and control for ecological prevention and control.【Method】Volatiles from the healthy and E. signifier-infected eucalyptus trunk and shallow soil of eucalyptus forest were extracted by dynamic headspace adsorption method. Components and contents of volatiles were determined through gas chromatography-mass spectrometry(GC-MS). Through random forest analysis, five volatiles were selected to determine the olfactory behavior of E. signifer larvae.【Result】Seventeen, forty-seven and twenty-three volatiles were identified in healthy trunk, ill trunks and shallow soil. Results of random forest analysis showed that:(-) -β-pinene, 3, 3-dimethyl-6-methylenecyclohexene and(-) -α-pinene were more important seen from comparison between volatiles from healthy and ill trunks; (-) -β-pinene, camphene, eucalyptol, o-cymene, 3, 3-dimethyl-6-methylenecyclohexene and(-) -α- pinene were more important seen from comparison of volatiles in eucalyptus trunks(healthy and ill) and shallow soil. Results of behavioral measurement showed that camphene and o-cymene(concentration of 10 mg/mL) had significant (P<0.05) and extremely significant(P<0.01) attraction to the 3rd instar larvae of E. signifer.【Conclusion】Both o-cymene and camphene in the volatiles of eucalyptus trunks can significantly attract the 3rd instar larvae of E. signifer, and their contents were both higher in the volatiles of ill eucalyptus trunks. It is speculated that the 2 components can regulate the host plant-seeking behavior of E. signifer larvae.

     

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