西藏产四种卷柏科植物的孢子形态观察

利用光学显微镜和扫描电子显微镜观察了西藏产4种卷柏科(Selaginellaceae)植物波密卷柏(Selaginella bomiensis Ching et S.K.Wu)、宽叶卷柏(S. megaphylla Baker)、墨脱卷柏(S. mutensis Ching)和钱形卷柏(S. nummularifolia Ching)的大、小孢子形态。扫描电镜观察结果显示：这4种卷柏科植物的孢子具有复杂的外部纹饰特征,且种间有很大的差异,可作为种间鉴别的重要分类依据。4种卷柏的孢子形态均为首次报道,为卷柏科系统演化及形态学研究提供有价值的基础资料。     

中国四种卷柏科植物孢子的形态观察

利用光学显微镜和扫描电子显微镜对睫毛卷柏(Selaginella ciliaris(Retz.)Spring)、甘肃卷柏(S.kansuensis Ching)、墨脱卷柏(S.mutensis Ching)、毛枝卷柏(S.trichoclada Alston)等4种中国产卷柏科(Selaginellaceae)植物的大、小孢子进行了详细的观察.结果表明,4种卷柏的大、小孢子在表面纹饰方面存在明显的差异,而在每一种内,孢子形态是基本稳定的.因此,孢子形态特征可以作为区分种的重要依据.4种卷柏的大、小孢子的孢壁多为混合纹饰类型,且近极面纹饰比远极面的细密.     

中国四种卷柏科植物孢子的形态观察

利用光学显微镜和扫描电子显微镜对睫毛卷柏（Selaginella ciliaris (Retz.) Spring）、甘肃卷柏（S.kansuensis Ching）、墨脱卷柏（S.mutensis Ching）、毛枝卷柏（S.trichoclada Alston）等4种中国产卷柏科（Selaginellaceae）植物的大、小孢子进行了详细的观察。结果表明,4种卷柏的大、小孢子在表面纹饰方面存在明显的差异,而在每一种内,孢子形态是基本稳定的。因此,孢子形态特征可以作为区分种的重要依据。4种卷柏的大、小孢子的孢壁多为混合纹饰类型,且近极面纹饰比远极面的细密。     

广西产5种卷柏科植物的孢子形态

利用光学显微镜和扫描电子显微镜首次观察了广西产5种卷柏科(Selaginellaceae)植物:纤毛卷柏S.albociliataP.S.Wang、秦氏卷柏S.chingiiiAlston、长芒卷柏S.commutataAlderw、似大叶卷柏SdecipiensWarb、S.pronifoliaBaker的大、小孢子形态。研究结果显示:5种卷柏科植物的外部形态结构复杂,并存在着较大的种间差异。为孢粉学和卷柏科的分类工作提供了有价值的基础资料。     

云南产8种卷柏科植物的孢子形态

利用光学显微镜和扫描电子显微镜首次观察了云南产8种卷柏科(Selaginellaceae)植物：钝叶卷柏Selaginella amblyphylla Alston;双沟卷柏S．bisulcata Spring;勃固卷柏S．kwrzii Baker;疏穗卷柏S．laxistrobilis K．H．Shing;微齿钝叶卷柏S．ormata(Hook．et Grev．)Spring;耳叶卷柏S．pseudopaleifera Hand.-Mazz;高雄卷柏S．repanda（Desv．ex Poir)Spring;泰国卷柏S．siamensis Hieron．的大、小孢子形态。研究结果表明卷柏科植物大、小孢子为辐射对称、三裂缝,其表面纹饰复杂,8种卷柏植物的大、小孢子在孢壁纹饰上存在着较明显差异。为卷柏科形态学和系统演化的研究提供了有价值的基础资料。     

海南七仙岭7种卷柏属植物的微观形态与生境间的关系分析

为探讨生境对卷柏属(Selaginella)植物微观形态的影响,利用扫描电子显微镜对海南七仙岭采集的7种卷柏属植物的侧叶、中叶、孢子叶的叶表皮形态以及小孢子形态进行全面观察分析,并计算气孔器大小、气孔密度、孢子大小等,比较分析其微观形态的区别及微形态与生境间的关系,为卷柏属植物的分类提供依据。结果显示:(1)同种卷柏属植物的侧叶、中叶与孢子叶在叶表皮形态上具明显差异,尤其是孢子叶上的气孔与营养叶相对较小且稀疏,与孢子叶的繁殖功能相符合。(2)不同种卷柏属植物的叶表皮特征也明显不同,主要表现在叶缘刺、气孔和瘤状突起上,表明这些特征可以作为卷柏属植物种间区分的依据。(3)卷柏属植物的小孢子形态稳定,纹饰多样;部分种间的小孢子形态相似,但可通过纹饰类型、裂缝的曲直进行区分。(4)琼海卷柏的小孢子具有独特的网状纹饰,暗示其具有独特的演化途径。(5)卷柏属植物叶表皮的气孔特征、瘤状突起特征,小孢子的颜色、纹饰,与海拔、生境的湿度有一定的相关性,但其形成机理有待进一步研究。     

中国实蕨属的分类修订

对实蕨属Bolbitis的17种植物的孢子进行了扫描电镜观察。根据孢子周壁特征,中国产实蕨属的孢子明显可分为3种类型：A型孢子具网状周壁,B型孢子具鸡冠状-波状周壁,C型孢子具平滑的波状周壁。孢子周壁特征、叶脉式样和叶片顶部的形态是实蕨属中最有价值的分类学性状。根据标本检查,结合野外调查和孢子形态观察,对中国产实蕨属的分类进行了修订,确定中国有实蕨属植物20种和3杂交种,其中包括2个新组合B. fengiana (Ching) S. Y. Dong和B. medogensis (Ching &; S. K. Wu) S. Y. Dong,以及2个中国新分布B. costata Ching ex C. Chr.和B. hookeriana K. Iwats.。将B. latipinna Ching、B. media Ching &; Chu H. Wang、B. yunnanensis Ching、Egenolfia crassifolia Ching、E. crenata Ching &; P. S. Chiu、E. fengiana Ching、E. medogensis Ching &; S. K. Wu和E. ×yunnanensis Ching &; P. S. Chiu等8个名称处理为新异名。文中给出了分种检索表、每个种的生境和分布资料、大多数种的特征集要和孢子扫描电镜照片。     

三种石杉属植物孢子形态的扫描电镜观察

利用扫描电镜对采自湖北省利川市的蛇足石杉Huperzia serrata（Thunb.ex Murray）Trev.、皱边石杉H.crispate（Ching ex H.S.Kung）Ching和四川石杉H.sutchueniana（Herter）Ching3种植物孢子的大小、形态及表面纹饰等方面进行观察测量,并对每个种孢子形态特征进行了描述。结果表明,3种石杉属植物孢子均为四面体型、三裂缝、辐射对称,表面纹饰均呈穴状。不同种在孢子大小、裂缝长度、孔穴深浅程度以及辐射间区凹陷程度上存在差异。因孢子形态是稳定的,可作为种间划分的重要依据,同时,也为蕨类植物孢子形态学的研究提供参考。     

越南莲座状复苏卷柏一新种——越南卷柏(卷柏科)

该文描述了在越南发现的卷柏科一新种——越南卷柏(Selaginella pseudotamariscina X. C. Zhang & C. W. Chen)。经过分子系统发育分析并与近缘种形态比较,认为该新种是卷柏属(Selaginella)同穗亚属(subg. Stachygynandrum)的一个物种,与S. digitata-S. imbricata分支为姐妹群关系。该新种与卷柏(S. tamariscina)和垫状卷柏(S. pulvinata)的形态近似,其植株均为莲座状,但不同之处在于中叶对称,似披针形,上表面具1沟槽; 孢子叶穗略压扁; 孢子叶和营养叶性状和排列近似,孢子叶非同形,略异形,正置,腹面孢子叶大于背面孢子叶; 背面孢子叶败育,孢子囊仅见于腹面孢子叶基部。     

中国蕨类植物孢子形态的研究ⅩⅣ.卷柏科

利用扫描电镜对中国产卷柏科25种植物孢子形态进行了观察。结果显示:(1)卷柏科植物大孢子为球状四面体,辐射对称;具三裂缝,裂缝为孢子半径的1/2~3/4;极面观一般为三角圆形或近圆形,赤道面观为近圆形、近扇形或近椭圆形;极轴长为158~548μm,赤道轴长为196~675μm。(2)小孢子为球状四面体,辐射对称;具三裂缝,裂缝为孢子半径的1/2~3/4或几达赤道线;极面观一般为近圆形或三角圆形,赤道面观为近圆形或近扇形;极轴长为10~40μm,赤道轴长为17~63μm。(3)孢子表面具颗粒状、瘤状、疣状、刺状、棒状、网状、片状、疣块状和脑状纹饰。研究认为,孢子形态特征可以作为该科亚属及种的分类学依据。     

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.     

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.     

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.     

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.