葫芦素B对美洲斑潜蝇成虫产卵和取食的抑制作用研究

美洲斑潜蝇是严重危害瓜、豆类蔬菜的世界性害虫之一,主要以幼虫潜伏在叶表皮下的叶肉组织中为害,给防治带来很大困难。本研究测定了葫芦素B对美洲斑潜蝇成虫产卵和取食的抑制作用。在非选择性试验中,当葫芦素B使用浓度为500~2000 mg/L时,对美洲斑潜蝇成虫的产卵抑制率达31.2~69.9%,对美洲斑潜蝇成虫的取食抑制率达61.7~64.9%;在选择性试验中,葫芦素B使用浓度达1000~2000 mg/L时,对美洲斑潜蝇成虫的产卵抑制率和取食抑制率分别为54.8~71.1%和57.2~65.2%;研究结果表明:利用葫芦素B可有效地抑制美洲斑潜蝇成虫的产卵和取食,减轻其幼虫的为害,为安全、有效地控制美洲斑潜蝇提供了一条新途径。     

南美斑潜蝇为害对黄瓜叶片中蛋白酶抑制剂活性及葫芦素B含量的影响

【目的】蛋白酶抑制剂和葫芦素是两类在植物中具有抗虫活性的化合物,在植食性昆虫与其寄主植物相互作用中起着重要的作用。本文在室内研究了南美斑潜蝇Liriomyza huidobrensis(Blanchard)为害对黄瓜叶片中蛋白酶抑制剂活性及葫芦素B含量的影响,以期揭示南美斑潜蝇与其寄主植物相互作用的机理以及为利用诱导抗性控制南美斑潜蝇的为害奠定必要的基础。【方法】用分光光度法和高效液相色谱法,分别测定了南美斑潜蝇幼虫为害后黄瓜叶片中蛋白酶抑制剂活性和葫芦素B含量的变化。【结果】在南美斑潜蝇幼虫为害期间(1~9 d),黄瓜叶片中胰蛋白酶抑制剂和胰凝乳蛋白酶抑制剂活性及葫芦素B含量与健康对照相比显著上升,但上升幅度并不与为害强度和为害持续时间相一致,其中对胰蛋白酶抑制剂具有系统诱导作用,而对胰凝乳蛋白酶抑制剂和葫芦素B的系统诱导作用不明显。【结论】南美斑潜蝇幼虫为害可诱导寄主植物体内蛋白酶抑制剂活性和葫芦素B含量上升,培育蛋白酶抑制剂或葫芦素含量高或易诱导的黄瓜品种可能是控制南美斑潜蝇为害的有效途径。     

瓜实蝇不同寄主种群对4种杀虫剂的敏感性

为探索瓜实蝇Zeugodacus cucurbitae不同寄主种群对杀虫剂的敏感性，本研究在室内通过药膜法测定了瓜实蝇节瓜、黄瓜、丝瓜和苦瓜种群4日龄成虫对4种杀虫剂的敏感性，随后将瓜实蝇不同寄主种群致死中浓度LC50进行比较，计算抗性倍数。结果表明，4个寄主种群对甲维盐的敏感性为节瓜 > 苦瓜 > 丝瓜 > 黄瓜，其中节瓜、苦瓜种群对甲维盐最敏感，其次是丝瓜、黄瓜，LC50值分别为0.250、0.391、0.809和1.035 mg/L。4个寄主种群对灭多威的敏感性表现为节瓜 > 黄瓜 > 苦瓜 > 丝瓜，LC50值分别为0.302、0.318、0.652和0.804 mg/L。对多杀菌素的敏感性大小依次为黄瓜、节瓜、丝瓜、苦瓜，LC50值分别为1.157、1.198、1.232和2.029 mg/L。对啶虫脒的敏感性为苦瓜 > 节瓜 > 黄瓜 > 丝瓜，LC50值分别为17.946、20.166、20.190和21.986 mg/L，其中对甲维盐的敏感性差异幅度最大，为4.140倍，其次是灭多威，为2.654倍，对啶虫脒的敏感性差异幅度最小，为1.225倍。表明寄主植物可引起瓜实蝇对杀虫剂的敏感性变化。     

守瓜属甲虫的取食行为与寄主植物葫芦素种类的关系

黄足黄守瓜和黄足黑守瓜是两个非常相似的守瓜属甲虫,但它们对寄主的选择性和取食行为却完全不同.黄足黄守瓜先用口器在黄瓜或南瓜叶面划圈,然后取食圈内叶组织,但却不取食丝瓜、苦瓜和西瓜,而黄足黑守瓜则只取食丝瓜,且不发生划圈取食行为.研究表明,这两种甲虫的寄主选择性及取食行为与瓜类作物合成的葫芦素种类显著相关.黄瓜和南瓜在黄足黄守瓜取食后能诱导合成抑制取食的葫芦素I,使得黄守瓜只能先划圈阻断葫芦素I在叶面的迁移才能取食圈内叶组织.而苦瓜和西瓜本身就合成抑制取食的葫芦素D,使得甲虫不选择这两种瓜类作物取食.丝瓜则合成刺激甲虫取食的葫芦素B和E,使得黑守瓜能直接取食.本研究表明,守瓜属甲虫对寄主植物合成的特定次生物质的味觉响应机制在其寄主选择和取食行为方面起着重要作用.     

B型烟粉虱在四种葫芦科寄主植物上的发育和繁殖

研究了B型烟粉虱在4种葫芦科寄主植物黄瓜、节瓜、苦瓜和丝瓜上的发育和繁殖特性.结果表明，B型烟粉虱在节瓜上的世代发育历期最短，为19.3 d，在苦瓜上的世代发育历期最长，为29.0 d；世代存活率在黄瓜上最高，为92.85％，在苦瓜上最低，为53.08％；平均单雌产卵量在黄瓜上最多，为187.4粒，苦瓜上最少，为30.0粒；雌成虫寿命以在黄瓜上最长，为25.2 d，在苦瓜上最短，为10.9 d.B型烟粉虱在黄瓜、节瓜、苦瓜和丝瓜上的内禀增长率（r_m）分别为0.1453、0.1429、0.0616和0.1055.综合比较4种葫芦科植物，黄瓜是B型烟粉虱的最适宜寄主.     

6种寄主果实对南瓜实蝇和瓜实蝇产卵选择 及其子代发育的影响

为探讨南瓜实蝇和瓜实蝇对不同寄主的产卵选择性及其与子代生长发育的关联度,采用生态测定方法,研究2种实蝇对南瓜、黄瓜、姜柄瓜、西葫芦、丝瓜和苦瓜6种寄主果实的产卵选择以及幼虫取食6种寄主后对其生长发育的影响。在产卵选择性试验中,2种实蝇对6种寄主的产卵选择性较为一致,均偏向于在丝瓜和黄瓜上产卵。在非产卵选择性试验中,南瓜实蝇在黄瓜和姜柄瓜上的产卵量较多;瓜实蝇在丝瓜和姜柄瓜上的产卵量较多;2种实蝇都对姜柄瓜有一定的偏好。在气味诱导的产卵选择性试验中,南瓜实蝇在姜柄瓜和黄瓜上的产卵量较多;瓜实蝇在黄瓜和丝瓜上的产卵量较多;2种实蝇都对黄瓜气味有一定的偏好;且南瓜实蝇和瓜实蝇都不偏好在苦瓜上产卵。南瓜实蝇分别取食黄瓜、苦瓜时,其幼虫期、蛹期较短;取食姜柄瓜时,蛹重最大;分别取食南瓜和黄瓜时的化蛹率、羽化率最高。瓜实蝇取食西葫芦时,幼虫期较短;取食丝瓜时,蛹期较短,且蛹重最大;分别取食黄瓜和南瓜时的化蛹率、羽化率最高。南瓜实蝇和瓜实蝇对不同寄主果实的产卵选择性均存在明显差异,寄主外部物理性状对实蝇的产卵选择有显著影响,2种实蝇对6种寄主果实产卵选择性和幼虫生长发育适应性的相关性不显著。     

南亚果实蝇对六种果实的趋性和产卵选择性

南亚果实蝇Bactroceratau(Walker)是危害黄瓜、南瓜、冬瓜、丝瓜和苦瓜等果蔬作物的一种重要检疫性害虫。趋性反应和产卵选择性实验结果表明,该虫对不同的果实切片具有不同的趋性和产卵选择性。在黄瓜、南瓜和丝瓜上,成虫的落虫数量分别占落虫总量的23.68%,19.94%和21.18%,产卵量分别占产卵总量的21.57%,18.93%和22.74%,均高于其它3种果实冬瓜、苦瓜和柑橘上落虫数和产卵量。幼虫在黄瓜、南瓜和丝瓜上取食的数量亦较高,分别占幼虫总量的23.33%,31.44%和21.67%;而在柑橘上仅占幼虫总量的2.22%。成虫和幼虫均对受害与未受害果实的趋性和选择性表现出一定的差异,总体上在受害果实上的虫口数量较多,而在未受害果实上的数量较少。因此,在这6种寄主植物中,南亚果实蝇喜好在黄瓜、南瓜和丝瓜以及受害的果实上获得补充营养或产卵。     

寄生蜂对美洲斑潜蝇自然种群控制作用的评价

应用作用因子生命表方法以及在此基础上提出的排除作用控制指数法评价了寄生蜂对美洲班潜蝇自然种群的控制作用,结果表明,底比斯釉姬小蜂,丽潜蝇姬小蜂,冈崎釉姬小蜂,异角姬小蜂,黄潜蝇姬小蜂,甘蓝潜潜蝇茧蜂和离潜蝇的种群数量将比原各群增长1．23,2．73,5．98,5．92和5．71倍,在春季菜豆,豇豆,丝瓜和黄瓜上第2代美洲斑潜蝇中,若排除寄生蜂作用因子后,美洲斑潜蝇在上述4种蔬菜上的种群数量将分别多增长2．73,2．87,2．24和1．89倍,寄生蜂对美洲班潜蝇3龄幼虫的控制作用大于1龄,2龄幼虫和蛹的控制作用;春季美洲斑潜连续世代中,第1,2代寄生蜂的控制作用较第3,4,5代低,寄生蜂有菜豆和豇豆上的控制作用比在丝瓜和黄瓜上高。     

寄主植物对锯叶裂臀瓢虫发育和繁殖的影响

【目的】锯叶裂臀瓢虫Henosepilachna pusillanima(Mulsant)是葫芦科植物上的一种植食性瓢虫,为瓜类蔬菜的主要害虫之一。本研究旨在探明不同瓜类植物对该虫发育和繁殖的影响。【方法】在(26±1)℃、相对湿度60%±5%、光周期L:D=14:10条件下,用棱角丝瓜Luffa acutangula(L.)Roxb.、南瓜Cucurbita moschata Duchesne x It、黄Cucumis sativus L、节瓜Benincasa hispida(Thunb.)Cogn.var.chieh-qua How和红瓜Coccinia grandis(L.)Voigt 5种植物的叶片饲养锯叶裂臀瓢虫,观察各虫态的生长发育进程和成虫的繁殖活动。【结果】不同寄主植物对锯叶裂臀瓢虫卵和各龄幼虫的发育、非成虫期以及产卵前期、产卵期、雌虫寿命和繁殖力均有显著影响,但预蛹期和蛹期不受寄主植物的影响。棱角丝瓜、南瓜、黄瓜、节瓜和红瓜上锯叶裂臀瓢虫非成虫期的平均历期分别为27.43、28.03、28.88、29.33、28.01 d。来自棱角丝瓜和红瓜的雌虫拥有较短的产卵前期、较长的产卵期和寿命。棱角丝瓜和红瓜上雌虫繁殖力也较强,其平均值分别高达2 039.79粒/♀和1 637.11粒/♀。5种瓜类植物上雌虫的逐日累计产卵率均完全符合三参数Weibull模型。【结论】锯叶裂臀瓢虫的5种寄主植物中,棱角丝瓜和红瓜拥有更高的适合度。     

美洲斑潜蝇幼虫潜叶为害对几种作物光合作用的影响

使用CI-310便携式光合作用测定系统研究了美洲斑潜蝇幼虫为害对几种作物光合作用的影响。结果表明,随着叶面积受害级别的增高,蓖麻和菜豆的光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr）和气孔限制值（Ls）总体呈下降趋势,不同受害级别与胞间CO₂浓度（Ci）的变化呈正相关。美洲斑潜蝇幼虫潜食蓖麻和黄瓜叶片中的栅栏组织后,叶片中叶绿素a、b和叶绿素总量都较对照减少,并且随着潜食级别的增高,减少量逐渐增大。叶面积受害级别与叶片的叶绿素总量之间呈高度负相关,其相关系数分别为r =-0.93（蓖麻）和r=-0.95（黄瓜）。菜豆、黄瓜和丝瓜的叶肉被害后,不同受害级别叶片的鲜重变化无规律性。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.     

（鱼句）亚科花（鱼骨）型鱼类骨骼系统的比较

对我国花型Hemibarbuspattern鱼类作了骨骼系统比较,结果表明,此类型鱼类脑颅较长,副蝶骨平直或稍弯曲,眶蝶骨腹纵嵴发达(铜鱼Coreius septentrionalis例外),下颞窝和咽突中等大,基枕骨后突发达;脑颅中的上筛骨的后突、侧筛骨的外筛突,蝶耳骨的外突、上耳骨的后突、围眶骨和后颞窝等均有明显的差异;咽颅中的舌颌骨、尾舌骨、鳃盖骨和下咽齿的列数等又有显著的区别;附肢骨骼中的腰带骨、脊椎骨中的复合神经骨和第4椎骨腹侧的悬器等也有不同之处。据此,这些差异和区别可作为属间或种间的分类依据。     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.