瘤坚大球蚧蜡泌物的超微形态与红外光谱特征

采用扫描电镜和红外光谱技术研究了瘤坚大球蚧Eulecanium gigantea在不同发育阶段蜡泌物的超微形态和化学成分。结果发现：该虫在低龄期分泌湿蜡,最初在虫体背面凝结成晶体状的不同大小颗粒,接着连接成片状和块状构造,最后蜡质堆积形成龟背状蜡壳。蜡壳的各个板块与体壁上突起的腺孔分布区位置相对应。雄虫蜡壳与低龄期若虫蜡壳质地相同。雌成虫分泌的蜡质为长而卷曲的空心蜡丝。雌成虫背面和腹面蜡泌物的红外光谱特征说明二者所含的主要化学基团和成分是相同的。尽管雄虫蜡壳与雌虫的化学成分基本相似,但存在的官能团有明显差别,主要表现在雄虫蜡泌物光谱图上1736.3 cm^-1处出现两个吸收峰,而雌虫只有一个;在振动频率1 242.0 cm^-1～1 106.6 cm^-1出现3个C-O键振动峰,而雌虫的是一系列锯齿状长碳链-C-C-C-骨架振动峰。根据红外光谱特征分析,推测该虫蜡泌物的化学成分可能主要是由长链烃、长链脂肪酸、脂肪醇和某些带芳香环的化合物组成。     

朝鲜毛球蚧蜡泌物的超微形态与红外光谱特征

采用扫描电镜和红外光谱技术研究了朝鲜毛球蚧Didesmococcus koreanus在不同发育阶段蜡泌物的超微形态和化学成分。结果发现：该虫在低龄期的蜡泌物的形态是长丝状,到3龄和成虫期是由湿蜡凝结成不同大小的颗粒,块状和片状。雄虫蜡壳是薄蜡片构成,表面呈鱼鳞状凹凸。低龄期若虫蜡泌物的红外光谱特征与雌成虫的十分相似,说明二者所含的主要化学成分是相同的,雄虫和低龄若虫及雌成虫蜡壳萃取物的红外光谱的吸收峰型基本一致,但在1 240.7 cm^-1处出现一个中等强度的特征峰,这充分说明3种蜡泌物的有机化合物种类和结构一致,只是雄虫分泌物与另二者比较具有特征官能团,从而,利用该吸收峰可以区别出雄虫。此外,根据红外光谱特征分析,可以知道该虫蜡泌物的化学成分主要为长链脂肪酸、脂肪醇和一些带芳香环的化合物。     

云南双蜡蚧蜡泌物的超微形态与化学成分

采用扫描电镜、红外光谱、气相色谱/质谱联用技术研究了云南双蜡蚧Dicyphococcus bigibbus Borchsenius（同翅目：蚧科）蜡泌物的超微结构和化学成分。结果发现：该虫的若虫与成虫分泌的蜡质从蜡腺排出初期均为湿蜡,在体外凝结形成质地稍硬而脆的玻璃状干蜡壳,蜡壳具有均匀脊和横层。幼期和雄性蜡壳小,船形,周缘带有蜡角,中央隆起。雌成虫蜡壳大,元宝形。蜡泌物的红外光谱吸收峰密集,峰型尖锐,种的特征明显。用红外光谱特征推断蜡泌物的主要基团和化学构成在GC/MS检测中得到印证。用甲酯化和非甲酯化两种处理方法检测证明,该虫蜡泌物主要成分是一系列高级的长链饱和与不饱和的烃、脂肪酸及酯类化合物。化合物的碳原子数从C₁₄～C₄₀,大部分为偶数个,特别是碳链长度在C₃₀～C₄₀的酯类化合物种类多,比例大。还将该蚧虫蜡泌物的特征与蚧科内近缘的蜡蚧属种类及瘤坚大球蚧、朝鲜毛球蚧、背刺毡蜡蚧、白蜡虫等作了对比,阐述了蜡泌物在蚧虫分类、系统学及防治中的意义。     

角蜡蚧和日本龟蜡蚧蜡泌物的超微结构及化学成分分析

采用扫描电镜和气相色谱/质谱联用技术研究了角蜡Ceroplastes ceriferus (Fabricius) 和日本龟蜡蚧C. japonicus Green蜡泌物的超微结构及化学成分。结果表明,这2种蜡蚧分泌蜡质和形成蜡壳的过程基本相似。在1、2龄期分泌的蜡质为“干蜡”,蜡壳为星芒状,虫体周缘的蜡芒均为2大节,与其2个龄期发育相对应,每一个大节又分为若干小节。同时,虫体背面中央蜡质堆积成帽状,也分为均匀的多层。由此说明泌蜡过程具有节律性。虫体周缘与蜡芒对应的突起区上分布着密集的刻点状腺孔,每一个腺孔分泌1根蜡丝,这在以往玻片标本中是观察不到的。雌性第3龄幼虫和成虫期,虫体分泌“湿蜡”,形成龟背状蜡壳,泌蜡腺孔主要为三格腺和四格腺。在肛突区发现了密集的泌蜡腺孔,排列为纵条纹状。从角蜡蚧蜡泌物甲酯化处理样品中检测到14个组分,从直接测试 (未经甲酯化处理) 样品中检测到14个组分;而从日本龟蜡蚧则分别检测到10个组分和25个组分。它们的主要成分是一系列高级的长链饱和与不饱和的烃、脂肪酸、脂肪醇、酯类、醛类以及杂环、多环或大环状化合物。对它们可能的生物生态学功能进行了讨论。     

扶桑绵粉蚧生物学特性研究

扶桑绵粉蚧Phenacoccus solenopsis Tinsley是近年在我国新发现的一种重要外来入侵害虫, 特别是对我国棉花生产具有潜在的巨大威胁,本文研究了实验室条件下（27±1℃, RH 70%±5%）该虫在棉花上的发育历期、 繁殖能力及各虫态的形态特征。结果表明：扶桑绵粉蚧雌虫生活史包括卵、1龄若虫、2龄若虫、3龄若虫和雌成虫;雄虫生活史包括卵、1龄若虫、 2龄若虫、预蛹、 蛹和雄成虫。卵期很短,雌虫若虫期15~20 d,总历期约为47~59 d;雄虫若虫和蛹期17~22 d,总历期约为20~26 d;雌虫寿命明显长于雄虫。该蚧虫繁殖能力强,雌成虫产卵量200~862粒/头,平均产卵458粒/头。各虫态主要形态特征为：卵呈长椭圆形,橙黄色, 略微透明; 1龄若虫,淡黄绿色,行动活泼;2龄若虫体缘突起显现, 尾瓣突出,至末期可根据体表黑斑的可见程度区分雌、 雄虫;3龄雌若虫, 体表有薄层蜡粉, 在前、中胸背面亚中区和腹部1~4节背面亚中区可见清晰斑点, 形成纵向黑色条斑, 外表形似雌成虫。雌成虫呈卵圆形,体表蜡粉厚实,胸、腹背面的黑色条斑在蜡粉覆盖下呈成对黑色斑点状,体缘蜡突明显,共18对,其中腹部末端2~3对较长; 雄虫蛹包裹于松软的白色丝茧中;雄成虫,虫体较小,黑褐色;触角细长,具一对发达透明前翅,后翅退化为平衡棒,腹部末端具2对白色长蜡丝。本文通过对扶桑绵粉蚧的基本生物学特性和各个龄期发育的形态特征的研究, 为该虫的进一步研究和科学防控提供了基本资料,具有重要的理论和实践意义。     

盾蚧科一新属和三新种

本文记述蚧总科盾蚧科三新种,分属三个属,其中一为新属,两个为我国大陆新记录属。模式标本保存予山西农业大学昆虫标本室。 晋盾蚧属Shansiaspis,新属 属模:Shansiaspis sinensis,新种(图1) 雌成虫介壳纺锤形,有时近三角形,前端尖,后端宽,白色。壳点2个,突出于前端,浅黄色,第二壳点有白腊层覆盖。雄介小而长形,二侧近平行,白色,背面略显一浅纵脊,     

筛安粉蚧属一新种(同翅目:蚧总科)

在研究竹类蚧虫的工作中,发现筛安粉蚧属一新种,现描述如下: 网孔筛安粉蚧Serrolecanium indocalmus 新种(图1—9) 雌成虫体长形,扁平,两侧平行;全体长约6毫米,宽2毫米;体全裸,无覆盖蜡被。口器较小,喙1节,位于前气门稍前之腹面中部。气门大型,前气门斜上方小管腺密集成扇形群分布,每个前气门外上方有一群,每群有45-50个;后气门之斜上方,小管腺密集成锥形群分布,每个后气门斜上方有一群,每群有28—30个;腺囊1对,位于第1、第2腹节     

南洋臀纹粉蚧雌成虫主要器官及其蜡泌物的扫描电镜观察

为明确南洋臀纹粉蚧Planococcus lilacinus(Cockerell)雌成虫及其蜡泌物的结构特征,利用扫描电镜观察该虫体表主要器官、蜡质及泌蜡腺体的超微结构.结果表明:南洋臀纹粉蚧雌成虫外覆白色粉状厚蜡被,体缘具18对蜡棒,触角8节、口器和足发达且分布有不同长度的毛形和刺形感受器,眼为单眼,腹脐和背孔唇形、发达;体表蜡质包含带状蜡丝、空心管状蜡丝和月牙形蜡丝,由三格腺和刺孔群分泌的带状蜡丝大量分布于整个虫体,由管状腺分泌的空心管状蜡丝主要分布于虫体腹部腹面和体缘,由多格腺分泌的月牙形蜡丝主要分布于虫体腹部腹面.研究结果初步揭示了南洋臀纹粉蚧雌成虫体表主要器官、蜡质及泌蜡腺体的超微结构特征,可为研究该虫搜索寄主、寻找配偶、群集为害、抵御逆境和传播扩散等行为活动提供支持.     

日本松干蚧不同虫态的泌蜡特点及FAS与FAE的含量变化

本文采用显微观察技术及酶含量测定方法,对日本松干蚧Matsucoccus matsumurae(Kuwana)分泌蜡质的几个虫态及各虫态虫体内与蜡质合成相关的脂肪酸合成酶(FAS)和脂肪酸延伸酶(FAE)的含量变化进行了研究。结果表明:雄性泌蜡主要在二龄若虫期和三龄若虫期,前者为珠形若虫,虫体分泌少量湿蜡,在体表形成薄蜡层,由气门周缘分泌蜡丝,后者泌蜡量大,为蜡丝结茧;雌性泌蜡主要在二龄若虫和雌成虫泌蜡形成卵囊期。FAS含量变化与泌蜡活动关系密切,在雄性的三龄若虫期最高,二龄若虫期次之,蛹期最低;雌性成虫泌蜡前和中期FAS含量最高,产卵完毕时最低,二龄若虫期居中;FAE含量与FAS变化相似,但在二龄若虫期也较高。这说明FAS和FAE参与了蜡质合成过程。     

柿白毡蚧蜡泌物的超微结构与蜡壳的形成

采用扫描电镜技术研究了柿白毡蚧Asiacornococcus kaki(Kuwana)泌蜡腺体、蜡泌物的超微结构与蜡壳形成过程.结果发现,蜡壳形成分3个阶段,即泌蜡发生期、泌蜡增长期和蜡囊形成期,由3种腺体分泌的蜡质构成.锥刺是泌蜡的主要器官,其分泌的粗蜡管形成蜡壳的框架.管腺分泌空心细蜡丝,与框架蜡管紧密交织在一起.单孔腺分泌的细小蜡丝散布虫体表面.雄茧扁平,由空心长丝状蜡编织形成.     

Cuticular waxes from potato (Solanum tuberosum) leaves

The qualitative and quantitative compositions of leaf cuticular waxes from potato (Solanum tuberosum) varieties were studied. The principal components of the waxes were very long chain n-alkanes, 2-methylalkanes and 3-methylalkanes (3.1-4.6 microg cm(-2)), primary alcohols (0.3-0.7 microg cm(-2)), fatty acids (0.3-0.6 microg cm(-2)), and wax esters (0.1-0.4 microg cm(-2)). Methyl ketones, sterols, beta-amyrin, benzoic acid esters and fatty acid methyl, ethyl, isopropyl and phenylethyl esters were found for the first time in potato waxes. The qualitative composition of the waxes was quite similar but there were quantitative differences between the varieties studied. A new group of cuticular wax constituents consisting of free 2-alkanols with odd and even numbers of carbon atoms ranging from C25 to C30 was identified.     

Mass spectrometric analysis of O-peracetylated derivatives of 1-monomycoloylglycerol isolated from Corynebacterium pseudotuberculosis, Rhodococcus rhodochrous and R. lentifragmentus

1-Monomycoloylglycerols from Corynebacterium pseudotuberculosis, Rhodococcus rhodochrous and R. lentifragmentus were reacted with acetic acid ahydride in the presence of pyridine. On infrared spectra the reaction products showed a sharp characteristic absorption of the acetyl ester group at 1235 cm-1; the hydroxyl group absorption (3400 cm-1) was absent. O-Peracetylated monomycoloylglycerols were analyzed by mass spectrometry under electron impact mode. The most common and representative peaks were associated to the following remarkable fragments: (a) peak at m/z 159 represented the backbone of the glycerol unit of peracetylated monomycoloylglycerols; it constituted the diagnostic and base peak of that group of compounds; (b) peak representing the glycerol moiety together with the alpha-subunit of the mycolic acid moiety; it gave the size of the chain length of the hydrocarbon side chain of that mycolic acid; and (c) a series of peaks of acylium ions minus 60 mass units (acetic acid) indicated the size of the chain length of the esterified mycolic acid. Therefore, acetylation of monomycoloylglycerol becomes the derivatized compound suitable for mass spectrometry. Moreover, the derivatives are more thermostable and resistant to pyrolysis. By associating these properties, separation and identification of homologs of monomycoloylglycerols are further expected.     

植物角质层蜡质的化学组成研究综述

角质层是植物与外界的第一接触面,而角质层蜡质则是由位于角质层外的外层蜡质和深嵌在角质层中的内层蜡质两部分构成。植物角质层蜡质成分极其复杂,具有重要的生理功能。综述了有关植物角质层蜡质的化学组成信息,探讨了目前植物角质层蜡质化学成分研究中存在的一些问题,展望了角质层蜡质成分的研究前景。     

Monoacylglycerols are components of root waxes and can be produced in the aerial cuticle by ectopic expression of a suberin-associated acyltransferase

The interface between plants and the environment is provided for aerial organs by epicuticular waxes that have been extensively studied. By contrast, little is known about the nature, biosynthesis, and role of waxes at the root-rhizosphere interface. Waxes isolated by rapid immersion of Arabidopsis (Arabidopsis thaliana) roots in organic solvents were rich in saturated C18-C22 alkyl esters of p-hydroxycinnamic acids, but also contained significant amounts of both alpha- and beta-isomers of monoacylglycerols with C22 and C24 saturated acyl groups and the corresponding free fatty acids. Production of these compounds in root waxes was positively correlated to the expression of sn-glycerol-3-P acyltransferase5 (GPAT5), a gene encoding an acyltransferase previously shown to be involved in aliphatic suberin synthesis. This suggests a direct metabolic relationship between suberin and some root waxes. Furthermore, when ectopically expressed in Arabidopsis, GPAT5 produced very-long-chain saturated monoacylglycerols and free fatty acids as novel components of cuticular waxes. The crystal morphology of stem waxes was altered and the load of total stem wax compounds was doubled, although the major components typical of the waxes found on wild-type plants decreased. These results strongly suggest that GPAT5 functions in vivo as an acyltransferase to a glycerol-containing acceptor and has access to the same pool of acyl intermediates and/or may be targeted to the same membrane domain as that of wax synthesis in aerial organs.     

两种吹绵蚧蜡泌物超微结构的研究

采用扫描电镜技术研究了澳洲吹绵蚧lcerya purchase Maskell和埃及吹绵蚧Icerya aegyptiaca(Douglas)不同龄期主要泌蜡腺体和蜡泌物的超微结构.结果发现:成虫期背面的丝状蜡是由多格腺和皮毛共同分泌产生的.卵囊是由雌成虫成熟时腹部腹面的半圆形卵囊带所分泌的,也是实心丝状蜡结构.若虫期吹绵蚧背面覆盖着由多格腺分泌的丝状蜡,实心结构;腹面有长丝状的蜡质缠绕,紧贴腹面体壁的还有一层小蜡圈.     

In situ analysis by microspectroscopy reveals triterpenoid compositional patterns within leaf cuticles of Prunus laurocerasus

The cuticular waxes on the leaves of Prunus laurocerasus are arranged in distinct layers differing in triterpenoid concentrations (Jetter et al., Plant Cell Environ 23:619–628, 2000). In addition to this transversal gradient, the lateral distribution of cuticular triterpenoids must be investigated to fully describe the spatial distribution of wax components on the leaf surfaces. In the present investigation, near infrared (NIR) Raman microspectroscopy, coherent anti-Stokes Raman scattering (CARS) microscopy, and third harmonic generation (THG) spectroscopy were employed to map the triterpenoid distribution in isolated cuticles from adaxial and abaxial sides of P. laurocerasus leaves. The relative concentrations of ursolic acid and oleanolic acid were calculated by treating the cuticle spectra as linear combinations of reference spectra from the major compounds found in the wax. Raman maps of the adaxial cuticle showed that the triterpenoids accumulate to relatively high concentrations over the periclinal regions of the pavement cells, while the very long chain aliphatic wax constituents are distributed fairly evenly across the entire adaxial cuticle. In the analysis of the abaxial cuticles, the triterpenoids were found to accumulate in greater amounts over the guard cells relative to the pavement cells. The very long chain aliphatic compounds accumulated in the cuticle above the anticlinal cell walls of the pavement cells, and were found at low concentrations above the periclinals and the guard cells.