不同状态下扁蓿豆挥发物成分分析及草地螟的触角电位反应

为筛选扁蓿豆中对草地螟Loxostege sticticalis具有生物活性的挥发物，采用动态循环吸附法收集健康、机械损伤和虫害3种状态下扁蓿豆地上部分的挥发物，利用气相色谱-质谱联用技术进行挥发物鉴定及相对含量分析，并选用含量较高的9种挥发物组分对草地螟进行触角电位（electroantennogram,EAG）测定。结果表明：在健康、机械损伤和虫害3种状态下，扁蓿豆释放的挥发物分别有41、43和38种，不同状态间其化合物种类及相对含量存在显著差异。扁蓿豆挥发物主要包括醇类、酮类、醛类、酸类、酯类、萜类、烷烃类、炔烃类和芳香烃类，其中醇类和酮类化合物的相对含量最高，酯类和芳香烃类的种类最多。草地螟对扁蓿豆9种挥发物有一定的EAG反应，反应强度表现为3-辛醇>4-乙基苯甲醛>3-辛酮>叶醇>芳樟醇>对异丙基苯甲醇>乙酸叶醇酯>对二乙酰基苯>3,4-二甲基苯乙酮，其中3-辛醇、4-乙基苯甲醛、3-辛酮和叶醇4种叶片挥发物可引起草地螟触角强烈的电生理反应，推测这些物质是对草地螟具有生物活性的化合物。

Analysis of volatiles from forage legume Medicago ruthenica under different conditions and electroantennographic response of beet webworm Loxostege sticticalis

In order to screen the volatile organic compounds of forage legume Medicago ruthenica that are biologically active to beet webworm Loxostege sticticalis, dynamic circulation adsorption was used to extract the volatiles from the above-ground parts of M. ruthenica under three different conditions (healthy, mechanically damaged and insect damaged). The volatiles and relative contents were identified and analyzed by gas chromatography-mass spectrometry (GC-MS), and nine volatiles with higher content were selected to measure the electroantennography (EAG) of L. sticticalis. The results showed that, under the three different conditions, there were 41, 43 and 38 kinds of volatiles released by M. ruthenica, respectively. The types and relative contents of volatiles released by M. ruthenica were diverse under different conditions. The main elements included alcohols, ketones, aldehydes, acids, esters, terpenoids, alkanes, alkyne and aromatic hydrocarbon. Among them, alcohols and ketones accounted for the highest relative contents, while esters and aromatic hydrocarbons exhibited the greatest variation.Through EAG analysis, it was found that M. ruthenica had EAG responses to the nine volatiles, with a response intensity from strong to weak as followed: 3-octanol, 4-ethylbenzaldehyde, 3-octanone, leaf alcohol, linalool, 4-isopropylbenzyl alcohol, cis-3-hexenyl acetate, 1,3-diacetylbenzene and1-(3,4-dimethylphenyl)ethanone. Four green leaf volatiles (3-octanol, 4-ethylbenzaldehyde, 3-octanone and leaf alcohol) could cause strong electrophysiological response to L. sticticalis. It was speculated that these substances might be bioactive compounds against L. sticticalis.