冬虫夏草菌丝状菌源增殖培养的研究

冬虫夏草菌是珍稀濒危名贵中药材冬虫夏草的无性型菌种,是侵染蝠蛾幼虫的唯一菌种,其侵染后形成名贵中药材冬虫夏草。冬虫夏草菌在不同营养及条件下生长形态不同,主要有丝状体和菌球体两种生长形态。冬虫夏草菌丝状菌体能够侵染蝠蛾幼虫,有可能作为一种新的接种体被广泛应用;但丝状菌体对营养要求苛刻、生长缓慢、菌丝体得率低的特点,阻碍了冬虫夏草菌丝状菌体作为侵染蝠蛾幼虫的接种体的开发及应用,从而阻碍了冬虫夏草人工培殖产业化的进程。为了提高冬虫夏草菌丝状菌体的生物表达量,本文对营养及培养条件进行了优化研究,得出了最佳条件为:葡萄糖质量浓度40 g/L、酵母粉质量浓度65 g/L、培养温度17℃、MgSO_4质量浓度3 g/L、KH_2PO_4质量浓度1.5 g/L、培养时间12 d,按最优培养条件,冬虫夏草菌丝状菌体干重得率15.67 g/L,为下一步新的接种体的制备提供菌源保障。     

冬虫夏草菌在寄主钩蝠蛾幼虫中的潜伏侵染过程研究

冬虫夏草是青藏高原的特色名贵药材,是冬虫夏草菌Ophiocordyceps sinensis寄生于钩蝠蛾幼虫后形成的虫生子囊真菌,其发生机理和侵染途径至今未知。本文利用real-time q PCR实时定量技术检测了寄主蒲氏钩蝠蛾Thitarodes pui幼虫表皮、脂肪体、血淋巴和肠壁等组织中冬虫夏草菌定殖量,分别建立了起始于表皮的侵染路径(R20.678)和起始于肠道的侵染路径(R20.271)两种Holt数学模型,经比较分析后,推论冬虫夏草菌随口腔摄食侵染寄主幼虫的方式具有一定合理性和可行性,揭示冬虫夏草菌可以通过进食途径实现其对钩蝠蛾幼虫的带菌生长、侵染和寄生,从而为深入阐释冬虫夏草菌与寄主钩蝠蛾幼虫相互作用关系提供重要参考。     

蝙蝠蛾幼虫肠道中的冬虫夏草菌体研究

西藏林芝地区冬虫夏草天然产区野生虫草蝙蝠蛾幼虫的肠道液pH范围为9.69-10.99,体外在此pH下培养冬虫夏草菌长势较差。同时,在该pH的体外模拟中肠液中,虫菌体也会在极短的时间内消亡,而对自然侵染的蝙蝠蛾幼虫的血淋巴、消化道及其“反吐物”（肠液）进行切片和显微镜检却发现,蝙蝠蛾幼虫消化道、呕吐物中均存在与血淋巴中相同的冬虫夏草菌菌体形态,生存状态良好,正常增殖,表明蝙蝠蛾幼虫肠道的生理状态可以维系并支撑冬虫夏草菌菌体某种形态的存在与生长,并证实冬虫夏草菌由口器及消化道入侵蝙蝠蛾幼虫的可能性;肠道虫菌体与血淋巴虫菌体不一定同时存在,表明冬虫夏草菌对蝙蝠蛾幼虫的侵染可能同时存在表皮侵染和肠道侵染两种途径。本文为冬虫夏草菌对蝙蝠蛾幼虫的侵染途径研究提供更加多样化的信息支持。     

冬虫夏草发生的影响因子

作为青藏高原高寒草甸特有的生物资源,冬虫夏草具有重要的药用和经济价值。特殊的生存环境决定了冬虫夏草的珍稀,外力的干扰和任何环境因子的变化都可能影响冬虫夏草的发生。蝠蛾属昆虫幼虫是冬虫夏草发生的营养和物质基础;高海拔分布决定了冬虫夏草发生所需的特殊气候和土壤条件;草甸植物为蝠蛾幼虫提供了丰富的食物资源;各种不同类型的天敌通过致病、捕食或寄生等作用对蝠蛾种群产生调节作用;过载放牧严重影响草甸植被的生长发育,并对冬虫夏草适生地草甸环境产生破坏作用;掠夺式采挖既破坏了环境也打断了冬虫夏草菌完成正常世代发育的链条。本文对影响冬虫夏草发生的各种因子进行了总结和分析,并指出了现有研究中存在的问题,为进一步开展冬虫夏草资源的可持续利用研究并拓展现有研究思路提供参考。     

人工培养冬虫夏草研究

冬虫夏草 [Cordycepssinensis (Berk .)Sacc .]是名贵中药和珍稀滋补品 ,是由其无性型中国被毛孢 (Hir sutellasinensisX .J .Liu ,Y .L .Guo ,Y .X .Yu&W .Zeng)侵染蝠蛾属 (Hepialusspp .)幼虫形成的菌虫复合体 ,分布在我国青海、西藏、四川、云南和甘肃等地的海拨 35 0 0～ 5 0 0 0m高寒灌丛草甸。自 1980年至今持续进行冬虫夏草的人工培养研究 ,分离获得了冬虫夏草的无性型菌株 ,经鉴定为中国被毛孢新种 ,并对其进行了一系列培养试验 :在培养基上能产生子座 ;低海拔环境下规模化室内饲养寄主昆虫成功 ,人工条件下 1年可完成寄主昆虫一个生活周期 ,且幼虫个体大 ;室内人工培养冬虫夏草取得成功。     

冬虫夏草线状菌体制剂对蝠蛾幼虫感染的研究

为明确冬虫夏草线状菌体制剂的侵染力,进行了冬虫夏草线状菌体制剂对蝠蛾幼虫的感染试验。在相同条件下对蝠蛾幼虫进行人工接种,并对感染温度、菌剂用量和虫龄进行了优化。结果表明冬虫夏草线状菌体具有侵染蝠蛾幼虫的能力,优化后的感染条件为:菌体剂量为5 g(即5个标准剂量)、幼虫虫龄为3龄、培养温度为14℃。该结果为蝠蛾幼虫新型接种体的制备与开发提供了依据。     

冬虫夏草寄主蒲氏钩蝠蛾实验种群生命表

蒲氏钩蝠蛾Thitarodes pui是分布在西藏色季拉山的冬虫夏草寄主昆虫种类之一,海拔分布范围4100～4650m,完成一个世代需要3～4年,其中幼虫期漫长,经过7～9次蜕皮、历时990～1350d才能完成发育,环境条件变化及天敌因子等都对蒲氏钩蝠蛾的种群稳定产生重要影响。采用分段饲养幼虫的方法,构建了蒲氏钩蝠蛾试验种群生命表,并分析了种群增长趋势。结果表明,蒲氏钩蝠蛾的世代总存活率为2.6%,种群趋势指数为7.95,下代数量将是当代数量的7.95倍。因此,低存活率仍能维持蒲氏钩蝠蛾实验种群的稳定增长。     

贡嘎蝠蛾幼虫血淋巴中游离氨基酸,海藻糖的初步研究

本文报道了冬虫夏草寄主——贡嘎蝠蛾幼虫血淋巴中游离氨基酸种类、含量及海藻糖含量,并与感虫草菌和人工饲养的贡嘎蝠蛾幼虫进行了比较。     

蝙蝠蛾幼虫肠道真菌复合体中的多菌种与中国被毛孢分生孢子联合侵染蝙蝠蛾幼虫提高侵染效能

应用真菌特异性引物PCR测序、克隆测序和SNP质谱基因分型法,鉴定2株蝙蝠蛾幼虫活体肠道的真菌分离株(CH1和CH2)中的多种菌物。应用这2株分离株与中国被毛孢分生孢子联合侵染蝙蝠蛾幼虫,观察其协同侵染活性。结果表明这2株分离株呈现中国被毛孢的体外培养生长和显微形态特征。通用引物ITS4/5和蝙蝠蛾拟青霉特异性引物Pp4/5扩增子测序检出蝙蝠蛾拟青霉和中国被毛孢ITS序列。扩增子克隆-测序和SNP基因分型法证实多种转换和颠换点突变基因型在2株分离株中共存。反复固体、液体培养证实蝙蝠蛾拟青霉和中国被毛孢ITS序列共存,并非真菌间DNA片段漂移。应用子囊孢子或中国被毛孢侵染4~5龄蝙蝠蛾幼虫,幼虫染菌率为1.37%~3.52%,幼虫变僵时间为35~50 d。应用2株分离株与中国被毛孢分生孢子联合侵染,幼虫变僵时间为5~8 d,染菌率达55.2%(P0.001),侵染效能提高15~39倍。蝙蝠蛾拟青霉和多种点突变基因型冬虫夏草菌(包括中国被毛孢)在蝙蝠蛾幼虫肠道以天然真菌复合体形式共存;多种菌物组成的侵染源联合侵染蝙蝠蛾幼虫大幅度提高侵染效能,呈现多菌协同侵染的共生关系。     

冬虫夏草菌侵染及寄生阶段的生长发育研究

冬虫夏草菌侵染进入寄主幼虫血体腔后,断裂形成长梭形的菌体。菌体以顶端出芽的方式增殖,分隔分化,互相质配。质配菌体生长出菌丝充满寄主幼虫血体腔,使幼虫死亡并形成僵虫形的菌核,菌核萌生子座即形成冬虫夏草。     

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.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

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.     

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。