对草地贪夜蛾有嗅觉生理活性的玉米和水稻挥发物组分

Corn and rice volatile components eliciting olfactory responses in Spodoptera frugiperda

入侵我国的草地贪夜蛾Spodoptera frugiperda(J.E.Smith)严重为害玉米但极少为害水稻。本研究旨在明确对草地贪夜蛾有嗅觉生理活性的玉米和水稻挥发物组分。笼罩试验表明,草地贪夜蛾偏好在玉米上产卵,触角切除后在玉米上的产卵量下降。采用动态顶空吸附法收集玉米和水稻挥发物,利用气相色谱-触角电位联用仪(GC-EAD)和气相色谱-质谱联用仪(GC-MS)定性确定挥发物中活性组分,发现玉米和水稻挥发物中分别有12种和10种能引起草地贪夜蛾嗅觉反应的活性组分,分属于绿叶气味、萜类物质、脂肪族化合物、芳香族化合物。其中,8种组分为玉米和水稻共有,4种玉米特有,2种水稻特有。采用触角电位仪测定草地贪夜蛾对不同浓度挥发物组分的触角电位反应(EAG),发现EAG反应随浓度(0.1~100μg/μL)增大而增强,但对某些组分的EAG反应在一定浓度后趋于稳定。癸醛、壬醛、反-2-己烯醛、反-2-己烯醇能引起草地贪夜蛾强烈的EAG反应。综上所述,玉米和水稻挥发物中对草地贪夜蛾有嗅觉生理活性的组分存在差异,这为进一步明确草地贪夜蛾对玉米和水稻的产卵选择行为奠定基础。

The fall armyworm(FAW),Spodoptera frugiperda,invaded China in 2019,severely damaging corn while rarely occurring on rice.This study aimed to determine corn and rice volatile components that elicit olfactory responses in FAW.Cage tests showed that,FAW preferred corn over rice for oviposition,and the egg production reduced when the antennae were excised.Active components were separated and identified by gas chromatography-electroantennographic detection(GC-EAD)and gas chromatography-mass spectrometry(GC-MS)from the volatiles of corn and rice collected by dynamic headspace adsorption.There were 12 and 10 olfaction-active components in corn and rice volatiles,respectively,which belonged to green leaf volatiles,terpenoids,aliphatic,or aromatic compounds.Among the active components,eight components were shared in corn and rice,four and two components were specific to corn and rice,respectively.The electroantennogram(EAG)responses of FAW to most active volatile components increased with increasing concentrations from 0.1 to 100μg/μL but were saturated at certain concentrations in some components.Decanal,nonanal,(E)-2-hexenal and(E)-2-hexen-1-ol induced the strongest EAG responses.In conclusion,the active volatile components that could elicit olfactory responses in FAW differed between corn and rice.These results provide a foundation for further clarification of the oviposition preference behavior of FAW.