豆野螟触角感器的电镜超微结构及嗅觉功能

本文利用扫描电镜(SEM)和触角电位仪(EAG)对豆野螟Maruca Testulalis (Geyer)触角感器的结构其及嗅觉功能进行了研究。豆野螟雌、雄成虫触角外部形态结构扫描的结果表明,豆野螟雌成虫触角上存在有毛形感器、刺形感器、腔锥形感器、耳形感器和栓锥形感器5种,雄成虫触角除上述5种感器外,还分布有柱形感器。以基部（触角的1/3）、中部（触角的1/3）和端部（触角的1/3）为单位,对雌、雄成虫触角节的各种类型感器数量进行统计,结果表明毛形感器、腔锥形感器、耳形感器在雌和雄虫触角上的分布都存在极其显著的差异。测定了豆野螟雄虫触角对性信息素化合物反,反-10,12-十六碳二烯醛和反,反-10,12-十六碳二烯-1-醇以及雌虫触角对植物挥发性化合物顺-3-己烯-乙酸酯和芳樟醇的EAG反应感应部位,结果表明EAG反应强弱与感器数量之间不存在明显的线性相关;对性信息素和植物挥发物有反应的触角感器在触角上的分布存在差异,对信息素反应的感器主要分布在触角鞭节的顶端24小节内(约占触角的1/3),而对植物挥发性化合物反应的感器则分布于触角鞭节顶端48小节内(约占触角的2/3)。     

绿盲蝽对性信息素类似物和植物挥发物的触角电位反应

为了更好地利用性信息素类似物与植物挥发物对绿盲蝽Lygus lucorum进行监测和生物防治, 本研究采用电生理学方法测试了绿盲蝽成虫对9种性信息素类似物和12种植物挥发性物质的触角电位(electroantennogram, EAG)反应。结果表明: 在测试的这21种化合物中, 绿盲蝽对丁酸酯类化合物和绿叶气味物质的EAG反应较强; 雄虫对性信息素类似物比雌虫更敏感, 而雌虫对植物挥发物更敏感。其中性信息素类似物中, 绿盲蝽对反-2-丁酸己烯酯的EAG反应最强; 植物挥发物中, 绿盲蝽对反-2-己烯醛的EAG反应最强, 雌虫对反-2-己烯醇、反-2-己烯醛、顺-3-己烯醇等绿叶气味物质的EAG反应相对高于萜类化合物的反应。剂量反应曲线表明, 在测定的浓度范围内, 雄虫对反-2-丁酸己烯酯的反应比雌虫显著高, 而对β 蒎烯的反应则比雌虫显著低。绿盲蝽成虫对性信息素类似物和植物挥发物的EAG反应存在的两性差异具有生态适应意义: 雄虫对性信息素类似物更敏感将更有利于其寻找交配对象, 而雌虫对绿叶气味物质更敏感将更有利于其寻找产卵寄主。     

竹横锥大象对寄主及虫体挥发物的行为和触角电位反应

为了探明竹横锥大象Cyrtotrachelus buqueti Guerin-Meneville是否存在两性间的引诱作用,以及寄主植物慈竹Neosinocalamus affinis笋对两性行为的影响,采用Y型嗅觉仪测定了竹横锥大象雌、雄成虫对4种虫体及寄主挥发物不同处理（雌、雄成虫,慈竹笋与雌、雄成虫的复合体）的行为反应,测定了触角不同部位对雌雄成虫3种虫体的提取物（整体、鞘翅、后肠）及其与寄主植物挥发物质联合作用的触角电位反应（EAG）。结果表明：雌成虫挥发物对雄虫有较高的引诱活性,对雌虫有驱避作用;雄成虫挥发物对雌虫有一定的引诱作用。雌、雄成虫对虫体与竹笋复合体气味的行为和电生理反应均显著或极显著高于对相应虫体挥发物的反应。经EAG测定,触角各部位对虫体不同部位挥发物的EAG值差异明显,触角端部对虫体与植物挥发性物质的联合作用EAG反应差异极其显著（P＜0.01）。竹横锥大象对沾染雌雄成虫虫体提取物的玻璃棒有一定的兴奋表现,雌虫兴奋率为6.67%,雄虫为26.67%。结果提示,竹横锥大象种内存在信息素,雌虫释放的信息素对同类雄虫有很强的引诱作用,而雄虫所释放的信息素对同类雌虫有引诱作用,添加寄主植物能够增强两性间的引诱效果。     

苹褐带卷蛾成虫对主要寄主植物挥发物的触角电位反应和行为反应

【目的】苹褐带卷蛾Adoxophyes orana是危害苹果、桃、梨、枣等果树的一种重要昆虫。近年来在陕西苹果和红枣产区发生面积逐年扩大,危害日趋严重。本研究旨在明确寄主植物挥发物在苹褐带卷蛾成虫嗅觉通讯中的作用,为开发植物源引诱剂提供基础数据。【方法】利用触角电位(electroantennogram, EAG)仪测定苹褐带卷蛾2日龄未交配雌、雄成虫对51种寄主植物挥发性化合物的EAG反应;利用本实验室开发的小型蛾类昆虫嗅觉行为测试装置测定苹褐带卷蛾成虫对15种具有显著EAG反应的挥发性化合物的行为反应。【结果】EAG测试结果表明,苹褐带卷蛾成虫对不同挥发性化合物的EAG反应相对值有显著差异,雌、雄成虫对顺-3-己烯-1-醇、反-2-己烯-1-醇、1-己醇、1-庚醇、己醛、反-2-己烯醛、庚醛、辛醛、壬醛、乙酸丁酯、乙酸异戊酯和乙酸-顺-3-己烯酯的EAG反应较强。此外,雄成虫对3-甲基-1-丁醇、1-戊烯-3-醇、苯甲醛、丁酸丁酯、乙酸乙酯、三甲基巴豆酸乙酯、己酸乙酯、丙酸丁酯、异戊酸-顺-3-己烯酯、苯甲腈和柠檬腈的反应较强。在待测的51种挥发性化合物中,苹褐带卷蛾成虫对29种化...     

绿豆象成虫对绿豆豆荚挥发物的触角电位和行为反应

【目的】探究对绿豆象Callosobruchus chinensi有引诱作用的植物挥发性物质。【方法】采用触角电位(EAG)仪和Y型嗅觉仪分别测定了绿豆象成虫对绿豆Vigna radiata豆荚挥发物的触角电位和选择行为反应。【结果】EAG测定结果表明,已交配的绿豆象雌虫对23种绿豆豆荚挥发物的EAG反应值存在显著差异,对苯甲醛、2-己烯醛、己醛、辛醛和水杨醛5种醛类化合物的EAG反应值相对较高,其中对2-己烯醛的反应值最大,达20.68;且绿豆象成虫EAG反应值在1~100μg/μL浓度下,均随挥发物浓度的提高而增强,但已交配和未交配绿豆象雌雄成虫的EAG反应值无显著差异。行为试验发现,当5种醛类物质浓度达100μg/μL时,已交配绿豆象雌、雄成虫均对苯甲醛和2-己烯醛有显著正趋性,对己醛有显著负趋性,对辛醛和水杨醛无显著趋性。【结论】绿豆豆荚挥发物中2-己烯醛和苯甲醛与绿豆象偏爱选择密切相关。     

烟蚜茧蜂对蚜虫信息素及烟草挥发物的触角电位反应

利用触角电位(EAG)技术测定了烟蚜茧蜂(Aphididius gifuensis)对蚜虫性信息素(荆芥醇和荆芥内酯)和报警信息素(反-β-法尼烯)以及烟草挥发性物质的电生理反应.结果表明:雌蜂和雄蜂对蚜虫性信息素、报警信息素、烟草挥发物均有反应,但雌雄蜂对这些化学信息物质的嗅觉敏感性存在差异,雌蜂对荆芥醇、荆芥内酯、顺-3-己烯-1-醇、反-2-己烯醛、水杨酸甲酯和里那醇的EAG反应都大于雄峰,证明雌雄蜂在利用寄主栖境中信息化学物质方面存在不同的策略,它们分别识别了不同的有关寄主的化学指纹图;烟蚜茧蜂对烟草气味组分具有不同的敏感性,对绿叶气味组分的EAG反应要强于对萜类化合物的反应,绿叶气味组分很有可能在其寻找桃蚜的过程中发挥远距离定向作用.     

甘薯蚁象对不同甘薯品种植物挥发物的EAG和嗅觉反应

【目的】为筛选对甘薯蚁象Cylas formicarius(Fabricius)有引诱作用的植物挥发性物质。【方法】采用顶空气体采样法收集5个甘薯品种的植物挥发物,通过气相-质谱联用系统(GC-MS)进行物质鉴定及定量分析,测定甘薯蚁象成虫对候选挥发物的触角电位(EAG)反应和嗅觉趋向选择行为。利用Y型嗅觉仪测定甘薯蚁象成虫对5个甘薯品种茎叶的嗅觉反应。【结果】5种甘薯品种的植物挥发物种类和含量有所差异。7种候选挥发物(罗勒烯、柠檬烯、壬醛、β-石竹烯、葎草烯、法尼烯和乙酸-顺-3-己烯酯)均引起甘薯蚁象雌、雄成虫的EAG反应。其中,雌虫对柠檬烯、壬醛和β-石竹烯的反应相对值较大;而引起雄虫反应相对值较大的挥发物为罗勒烯、柠檬烯、葎草烯。在趋向行为反应中,柠檬烯和壬醛对甘薯蚁象雄虫的吸引作用高于对照,而雌虫对葎草烯、柠檬烯有极显著的趋向选择。甘薯蚁象成虫对5种茎叶的反应率为40.90%~65.21%,且5个甘薯品种的茎叶挥发物均没有显著的引诱作用(P0.05)。【结论】甘薯蚁象雌、雄成虫对甘薯植物挥发物具有不同的EAG及趋向行为反应,气味化合物柠檬烯与甘薯蚁象偏爱选择密切相关。     

横坑切梢小蠹对植物挥发物的电生理和行为反应

为筛选出适宜配制横坑切梢小蠹(Tomicus minor Hartig)引诱剂的有效化合物,测定了横坑切梢小蠹雌、雄成虫对寄主云南松主要挥发性化合物的触角电位(EAG)和行为反应。结果表明:与对照相比,在10 g·L-1浓度刺激下所测试的9种植物挥发物都能引起横坑切梢小蠹雌、雄虫触角的EAG反应,且触角对不同挥发物的EAG反应差异显著(P0.05),其中雌、雄虫对(+)-α-蒎烯、(+)-柠檬烯、(+)-3-蒈烯、β-蒎烯和异松油烯的EAG反应较强;在剂量反应试验中,雌、雄虫的EAG反应都随着(+)-α-蒎烯、(+)-柠檬烯、(+)-3-蒈烯和β-蒎烯浓度的增加而增强,当浓度增加到10 g·L-1时,EAG反应最强;而雌、雄虫对异松油烯的EAG反应在1 g·L-1最强;除(+)-柠檬烯没有明显的定向作用外,(+)-α-蒎烯、β-蒎烯、(+)-3-蒈烯和异松油烯对横坑切梢小蠹均表现出了明显的引诱作用;行为反应多重比较表明,(+)-α-蒎烯在10 g·L-1浓度下对雌雄虫的引诱作用最大。该研究结果可为开发横坑切梢小蠹林间引诱剂提供参考。     

桔小实蝇对几种寄主挥发物的触角电位反应

桔小实蝇寄主范围广,可危害芒果、柑橘、咖啡和红辣椒等250多种水果和蔬菜,现已成为中国、东南亚、印度次大陆和夏威夷群岛一带的危险性果蔬害虫。本文利用触角电位(electroantennogram,EAG)技术,测定了桔小实蝇雌雄成虫对8种寄主挥发物标准化合物(1,8桉叶素、α-蒎烯、β-石竹烯、柠檬醛、香草醛、乙醇、芳樟醇和月桂烯)的EAG反应。结果表明:上述标准化合物均能引起EAG反应,EAG反应值随着浓度增大(0.1μg/μL、1μg/μL、10μg/μL和100μg/μL)而显著不同。当柠檬醛和月桂烯浓度为100μg/μL时,桔小实蝇雌虫交配前、后的EAG反应值存在显著性差异。浓度为100μg/μL的1,8桉叶素对桔小实蝇交配后雌虫和雄虫的刺激反应存在显著性差异。桔小实蝇交配前雌虫和雄虫对浓度为100μg/μL乙醇的EAG反应值存在显著性差异。     

华北大黑鳃金龟对桃树挥发物的电生理反应

【目的】华北大黑鳃金龟Holotrichia oblita是一种分布范围广,寄主种类多的农业害虫。本研究鉴定了桃树顶空挥发物中对华北大黑鳃金龟雌虫具有触角电生理活性的化合物,并探索桃树挥发物活性成分的剂量对华北大黑鳃金龟雌、雄虫触角电生理反应的影响。【方法】采用顶空吸附法收集桃树枝叶挥发物,用气相色谱 触角电位联用技术(GC-EAD)和气相色谱 质谱联用技术(GC-MS)鉴定有电生理活性的桃树挥发物成分,最后用触角电位(electroantennograph, EAG)技术测试这些挥发物在0.01,0.1, 1, 10和100 μg剂量下引起的华北大黑鳃金龟雌、雄成虫EAG反应。【结果】桃树挥发物中能引起华北大黑鳃金龟雌成虫触角电生理反应的成分有7种,包括Z-β-罗勒烯、顺-3-己烯乙酸酯、顺-3-己烯醇、壬醛、水杨酸甲酯以及2种未知化合物。所测试的对华北大黑鳃金龟雌成虫触角具有电生理活性的5种桃树挥发物成分在各剂量下都能引起雌、雄成虫明显的EAG反应。雌、雄虫对同种物质的EAG反应随着剂量的增加而有增大的趋势,并且雌虫的EAG反应显著高于雄虫。【结论】桃树挥发物中,罗勒烯、顺-3-己烯乙酸酯、顺-3-己烯醇、壬醛、水杨酸甲酯均能引起华北大黑鳃金龟雌、雄成虫的剂量依赖性的触角电生理反应,而且存在显著的性别差异。可利用这些化合物开展行为反应和田间诱集试验,进一步验证其对华北大黑鳃金龟的引诱活性。     

Electroantennogram responses of Plutella xylostella (L.), to sex pheromone components and host plant volatile semiochemicals

The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a notorious insect pest of cruciferous crops worldwide. Attract-and-kill strategies to manage the DBM based on insect pheromone and plant volatile semiochemicals have been explored and partially applied in the field. However, little is known about whether the attractant effects of insect pheromone and host plant volatile semiochemicals on insects are affected by insect age or volatile concentrations. Therefore, we examined the electroantennogram (EAG) responses of both DBM males and females varying in age and body size to a range of concentrations of seven host plant volatiles and two main female sex pheromone components. Our results showed that DBM age had no influence on EAG responses to trans-2-Hexenal, trans-2-Hexenol, Heptanal, cis-3-Hexen-1-ol and Z11-16:Ald and significantly influenced the EAG responses to Z11-16:Ac and three isothiocyanates. Age and sex had interaction effects on EAG responses of DBMs to some tested semiochemicals. DBM females had significantly stronger responses than males to all tested plant volatiles, and values were enhanced with increasing concentrations. Moreover, the degree of enhancement of EAG responses in females was larger than that in males for trans-2-Hexenal, trans-2-Hexenol, cis-3-Hexen-1-ol, 2-Phenylethyl isothiocyanate and Methyl isothiocyanate treatments. Body size seemed to have no influence on EAG responses. Our results might provide a theoretical basis for optimizing attract-and-kill strategies for insect pests.     

Electroantennogram responses of the three migratory forms of the damson-hop aphid, Phorodon humuli, to aphid pheromones and plant volatiles

Electroantennogram (EAG) responses were recorded from alate fundatrigeniae (spring migrants), gynoparae (the winged female form that produces sexual females) and males, the three migratory forms of the damson-hop aphid, Phorodon humuli (Schrank). EAG responses of gynoparae and males showed typical dose response characteristics to (E)-2-hexenal, (-)-R-carvone, hexanenitrile and (1RS,4aR,7S,7aS)-nepetalactol, the sex pheromone of this species. The 34 plant volatiles elicited broadly similar EAG response profiles in the three migratory forms. Green leaf volatiles produced large responses in all forms; however, the relative order of responsiveness varied. EAG responses to isomers of the monoterpene carvone differed between forms, with males being most, and spring migrants least, responsive. The hop-plant volatile and aphid alarm pheromone, (E)-beta-farnesene, evoked similar EAG responses in all forms. By contrast, males were most responsive to the three sex pheromone components, (-)-(4aS,7S,7aR)-nepetalactol, (+)-(4aS,7S,7aR)-nepetalactone and (1RS,4aR,7S,7aS)-nepetalactol. Males were no more responsive to their own sex pheromone, (1RS,4aR,7S,7aS)-nepetalactol, than to the other aphid sex pheromone components tested. Spring migrants and gynoparae also responded to the three sex pheromone components. This study indicates that migratory forms of P. humuli detect a wide range of volatile compounds, and that they are equally well-adapted for the detection of volatiles associated with host and non-host plants and with other species of aphid.     

Electroantennogram responses of the carrot fly, Psila rosae, to volatile plant components

ABSTRACT. Electroantennogram (EAG) responses of male and female carrot flies, Psila rosae F. (Diptera: Psilidae), were recorded to thirty-six volatile plant constituents. The most distinct EAG responses were obtained to: (1) the general green leaf volatiles 1-hexanol, trans-2-hexen-1-ol and cis-3-hexen-1-ol, their isomers cis-2-hexen-1-ol and trans-3-hexen-1-ol, the alcohol 1-heptanol, the ester cis-3-hexenyl acetate and the leaf aldehydes hexanal and trans-2-hexenal, and (2) from four compounds associated with the umbelliferous host plants of this insect, namely trans-methyl-iso-eugenol, β-caryophyllene, linalool and trans-2-nonenal. Higher responses were elicited by the leaf aldehydes than by the corresponding alcohols. Although the absolute amplitude of the female response was over twice that of the male, there were no differences between the relative responses to the compounds tested in both sexes, with the exception of a much higher response to the leaf aldehydes in the male. The shape of the EAG evoked by the various compounds was consistently different, with the slowest recovery being recorded for trans-methyl-iso-eugenol. While the antennal olfactory receptors of the carrot fly are sensitive to the closely related general green leaf volatiles, they are most specifically tuned to the aldehyde component of this green odour complex. In addition, the ability of this insect to discriminate between different plants may be augmented by the perception of a group of more host specific volatiles. The conformity of the responses of males and females to the compounds tested may indicate that host plant volatiles plays an additional role as an aggregation cue for both sexes.     

Functional specialisation and polyphenism in aphid olfactory sensilla

Electroantennogram (EAG) responses to the aphid sex pheromone components, (1R,4aS,7S,7aR)-nepetalactol and (4aS,7S,7aR)-nepetalactone, and a plant volatile, (E)-2-hexenal, were investigated at three different positions (5/6th, 4/5th and 3/4th inter-segmental regions) along the antennae of four different morphs in two host-alternating aphid species, Aphis fabae Scopoli and Rhopalosiphum padi (L.). Position-dependent and morph-specific EAG responses were elicited in both species. The nepetalactol and nepetalactone isomers elicited large EAG responses at all three recording positions in males of both species, such that primary rhinaria as well as secondary rhinaria appeared to respond. Asexual female morphs showed relatively smaller EAG responses to these compounds. The secondary rhinaria, which have been reported as sex pheromone receptors in males, were not very different in their number and distribution between gynoparae and alate virginoparae, but the gynoparae showed significantly larger EAG responses to nepetalactol and nepetalactone. The alate virginoparae showed EAG responses that were similar to those of apterous virginoparae, which lack secondary rhinaria. Taking the EAG response profiles together with the distribution of the secondary rhinaria, it is suggested that the function of secondary rhinaria differs between the morphs. Secondary rhinaria appear to detect sex pheromone components in males and gynoparae but not in the alate virginoparae. If they are functional in the latter morph, they are likely to play a role in detecting specific, but as yet unknown, volatile compounds. Some 30 plant volatiles were tested but none evoked an EAG response that could be allocated to the secondary rhinaria. In contrast to the very different EAG response profiles to the pheromone compounds between morphs, EAG responses to (E)-2-hexenal were similar in all forms and both species. These findings suggest that this plant volatile was detected only by the two primary rhinaria, which are common to all morphs. The present study showed that EAG responses were not a simple summation of receptor potentials between recording and reference electrodes in aphids. The localised distribution pattern of olfactory receptor neurones around the recording electrode was also likely to contribute to the EAG responses.     

Perception of volatiles associated with sex and food by different adult forms of the black bean aphid, Aphis fabae

Abstract. Electroantennograms (EAGs) were recorded from adult male and asexual forms (winged and wingless virginoparae and gynoparae) of the black bean aphid, Aphis fabae , during stimulation with two sex pheromone components, (+)-(4a S ,7 S ,7a R )-nepetalactone and (-)-(1 R ,4a S ,7 S ,7a R )-nepetalactol, as well as six plant volatiles, i.e. ( E )-2-hexenal, ( E )-2-hexenol-1, ( Z )-3-hexenol-1, ( Z )-3-hexenyl acetate, hexanal and allyl isothiocyanate. The male antennae are 1000-10,000 times more sensitive to nepetalactol and nepetalactone than to the plant compound ( E )-2-hexenal. Besides this marked difference of EAG peak responses in males, the EAG rise and decay are slower for the sex pheromone components. Males are also much more sensitive to the sex pheromone components than asexual females. This high sensitivity correlates with a predominance of antennal secondary rhinaria, the major sites of pheromone perception in the male. However, it is the primary rhinaria on the antennae of the wingless asexual females that are responsible for pheromone perception. Male antennae are as responsive as the asexual female antennae to the plant volatiles. The specialization of the male for mate location is discussed.     

钝叶榕榕果内榕小蜂的产卵顺序及其群落结构

通过对钝叶榕榕小蜂行为的观察以及榕果内各类小花的统计,研究了钝叶榕12种榕小蜂的产卵行为和群落结构.结果表明：钝叶榕中除了传粉榕小蜂Eupristina sp.进入果腔产卵以外,还有2种非传粉榕小蜂（杨氏榕树金小蜂和Lipothymus sp.）与传粉榕小蜂在同一时期进入果腔产卵,其他9种非传粉榕小蜂（Walkerella sp.、Micranisa sp.、Sycophilomorpha sp.、Philotrypesis sp.、Sycosapter sp.、Sycobia sp.、Ficomila sp.、Ormyrus sp.和Sycophila sp.）在果外产卵;在钝叶榕榕小蜂群落中,传粉榕小蜂占整个群落总数的62.11%,是该群落的优势种,杨氏榕树金小蜂和Lipothymus sp.分别占整个群落总数的27.19%和4.71%,其他9种非传粉榕小蜂占5.99%.钝叶榕中的非传粉榕小蜂通过各自产卵时序和幼虫食性分化的繁殖策略来分配榕果中的资源,以实现自身繁殖.非传粉榕小蜂与传粉榕小蜂的数量变化呈显著负相关,但非传粉榕小蜂与榕果内的种子没有相关性.     

Olfactometer Responses of Plum Curculio <Emphasis Type="Italic">Conotrachelus nenuphar</Emphasis> (Herbst) (Coleoptera: Curculionidae) to Host Plant Volatiles,Synthetic Grandisoic Acid,and Live Conspecifics

The plum curculio Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae) is a major pest of pome and stone fruit, but will also attack other fruits. Males produce the aggregation pheromone grandisoic acid; emitting only the (+)-enantiomer which is attractive to both sexes of the univoltine and multivoltine strains, while the synthetic racemic mixture contains optical isomers with equal amounts of (+)- and (?)-enantiomers. Synergy between odours can increase trap captures and improve monitoring techniques, therefore tests were performed in a dual-choice olfactometer with odours attractive to plum curculios according to literature to determine 1) under what physiological conditions (mating status, age, starvation period) these odours are attractive or repulsive, 2) if the (+)-enantiomer or the odour of live males synergizes with host plant volatiles, and 3) if there is a difference in response between plum curculio strains. Females were exposed to: benzaldehyde; trans-2-hexenal; apples; extracts of: plums, apples, blueberries; grandisoic acid; and live males. Plum essence was found to be the most attractive host-plant odour for both immature and mature virgin females, and immature whole apples were attractive to starved females, while trans-2-hexenal, McIntosh apple essence, benzaldehyde along with the combination of benzaldehyde and plume essence was found to be repulsive. Starvation, age, and mated status all influence response to odours. No synergistic or additive affects were observed between any of the odour combinations tested, including the combination of both the natural and synthetic pheromone and plum essence or apples.     

环境胁迫对岷江干旱河谷豆科灌木幼苗根系生长及其结瘤的影响

通过野外调查,分析了岷江干旱河谷海拔梯度上相同年龄段的白刺花、岷谷木蓝和小雀花幼苗根系结瘤、生物量积累、生物量百分比的变化及其相互关系;人为控制土壤水分（田间持水量(WHC)的80%、60%、40%和20% 4个水平）研究了干旱对2月龄的白刺花与小雀花幼苗结瘤能力的影响.结果表明：1)干旱河谷低海拔地段(1600～1950 m)幼苗的结瘤能力都很低,白刺花、岷谷木蓝和小雀花的平均结瘤数分别为每株(0.1±0.1)、(0.9±0.5)和(5.7±1.9)个,未结瘤的个体分别占651%、123%和176%;总体上随着海拔的升高,3种幼苗的根瘤数均呈增加趋势,且与细根百分比及根长正相关.2)土壤水分低于60% WHC时,白刺花与小雀花的根瘤数及生物量均明显减小;在20% WHC条件下,白刺花根瘤数为0,小雀花根瘤数为每株(9.8±3.6)个.综合分析发现,干旱河谷地区豆科灌木的结瘤固氮能力很低,土壤水分在40% WHC以上时其生物固氮才能有效发挥,与白刺花相比,小雀花结瘤能力较高,干旱忍受性较强.     

Increased EAG responses of tortricid moths after prolonged exposure to plant volatiles: evidence for octopamine-mediated sensitization

As measured by electroantennograms (EAG), both male and female obliquebanded leafrollers, Choristoneura rosaceana (Harris), and redbanded leafrollers, Argyrotaeniavelutinana (Walker), were similarly sensitive to host-related plant volatiles: trans-2-hexenal, benzaldehyde, 1-hexenol, cis-3-hexen-1-ol, geraniol, linalool, (+)-limonene, hexenal and trans-2-hexenol. Females of both species were similarly sensitive to the shared major component of their sex-attractant pheromone ((Z)11-14:Ac). Continuous 60 min pre-exposure of male and female C. rosaceana and A. velutinana to successively higher concentrations of a mixture of the nine plant volatiles in Teflon chambers with continuous air exchange caused a dosage-dependent increase in subsequent responsiveness (sensitization) to green leaf volatiles, as measured by EAGs. In addition, 60 min of pre-exposure of male C. rosaceana to certain individual volatiles ((+)-limonene, geraniol, benzaldehyde) increased EAGs nearly as much as did the mixture of nine volatiles. Pre-exposures to the nine plant-volatile mixture at concentrations achieved by 100 microg and 1 mg loading dosages in 100 microl of mineral oil significantly increased EAG depolarization to pheromone (cross-sensitization) in males but not females of both moth species. Antennae of male C. rosaceana pre-injected with 100 microg of octopamine (OA) without volatile pre-exposure exhibited sensitization nearly identical to that induced by pre-exposing moths to sensitizing concentrations of the plant-volatile mixture. Moreover, injection of the OA antagonist chlorpromazine (CP) blocked sensitization by the plant-volatile pre-exposure. Collectively, these findings suggest that exposures of tortricid moths to certain host-plant related volatiles may modulate subsequent olfactory sensitivity to behaviorally relevant chemical cues and that plant-volatile induced sensitization may be octopamine mediated.     

芒果不同部位挥发物及横线尾夜蛾对其触角电位反应

【背景】芒果横线尾夜蛾是严重危害芒果花序和嫩梢的重要害虫,其发生面积不断扩大,给我国南方芒果造成了巨大损失。【方法】通过气质联用仪（GC-MS）对芒果花、梢和成熟果实的挥发性物质及其相对含量进行分析;采用触角电生理方法,测定不同性别和交配状态的芒果横线尾夜蛾对12种芒果挥发物的触角电位反应。【结果】芒果3个部位的挥发性物质多为萜烯类化合物,主要物质（相对含量在O．06％以上）的数量分别为芒果花中22种、梢11种和成熟芒果13种。芒果花中含量较高的为d．水芹烯（43．64％）和异松油烯（29．33％）;芒果梢中α-古芸烯（23．63％）含量最高;成熟芒果中8-石竹烯含量最高,为29．47％。仅异松油烯和β-荜澄茄油烯在芒果3个部位中均被检测到,但其含量差异较大;异松油烯在花、梢、果实中的含量分别为29．33％、19．99％、0．59％,而β-荜澄茄油烯分别为3．51％、2．18％、6．05％。芒果横线尾夜蛾未交配雌、雄蛾和已交配雌、雄蛾对同一种化合物的触角电位相对值之间均无显著差异。4种成蛾对反-2-已烯醛的触角电位反应值与其他化合物相比均有显著差异。交配后雌、雄蛾的触角电位反应值均有所降低,但与交配前相比无显著差异。【结论与意义】筛选出的反-2-己烯醛可作为横线尾夜蛾信息素的增效物质,对性引诱剂的研制具有重要意义。本研究可为从化学信号角度阐明横线尾夜蛾寄主定向和雌、雄交配机理,以及其致害机理提供依据。