国产柽柳科3属6种植物营养枝的解剖观察

对国产柽柳科3属6种植物(琵琶柴、沙生柽柳、山川柽柳、多枝柽柳、刚毛柽柳、疏花水柏枝)营养枝解剖结构的比较研究表明：其当年生营养枝在表皮是否具毛、皮层细胞的形态结构、维管束排列方式、形成层的发生、髓部面积及内含物等性状上存在差异,并根据这些差异列出了分属检索表。所选6种植物生态型各不相同,其中琵琶柴为地带性超旱生小半灌木,柽柳为非地带性的潜水性旱、中生灌木,疏花水柏枝为湿、中生灌木。通过比较这6种植物的解剖结构,发现随着生境由湿生向旱生变化,营养枝解剖结构也发生了相应的变化,并与生境形成了良好的适应。     

德保苏铁茎的解剖学研究

对德保苏铁茎、叶柄的解剖构造进行观察,结果表明:(1)德保苏铁的茎由周皮、皮层、维管束、髓四部分构成。木栓层的细胞壁完全栓化;皮层大而显著,皮层细胞一般较小,富含淀粉,分布有粘液道;维管束通常较小,主要集中在皮层和髓之间的狭窄区,排列呈环形,具2生长环;少部分稀疏地散生在皮层薄壁细胞之间。(2)叶柄由表皮、绿皮层、下皮层、基本组织、维管束、髓组成。表皮细胞1层,细胞外壁角质化;绿皮细胞2层,有叶绿体;下皮层的厚壁细胞,大小不一,细胞壁强烈增厚;维管束散生,属外韧维管束,排列呈环形,内有零星分布的维管束。     

两种盐生植物解剖结构的生态适应性

结合对研究区域土壤水分和盐分的分析,对3种不同生境下梭梭和多枝柽柳两种荒漠盐生植物光合器官解剖结构的研究表明:梭梭(Haloxylon ammodendron)依靠当年生绿色同化枝进行光合作用,且同化枝具有发达的贮水组织,是典型的超旱生稀盐盐生植物;同化枝的栅栏组织富含叶绿体,是C_4高光效植物,提高了植物的光合作用效率,进一步增强了梭梭对荒漠干旱、盐渍化环境的适应能力.多枝柽柳(Tamarix ramosissima)同化枝及叶的表皮上均具下陷的气孔和泌盐腺,是旱生泌盐盐生植物;叶为全栅型,且同化枝具有发达的维管柱,占同化枝直径的60%以上,此外,其同化枝及叶的表皮细胞外凸形成乳状突,是一种环境胁迫指示结构.这些特征均能说明梭梭和多枝柽柳具有很好的抗旱、耐盐碱能力,且作为荒漠环境的优势树种,它们对荒漠生态系统的恢复和重建有积极意义.     

高寒草甸矮生嵩草不同根序解剖结构对生境干旱化的响应

植物根系由不同根序组成,然而,它们的解剖结构对生境干旱化的响应是否一致尚不清楚。本研究于藏东南东达山矮生嵩草(Kobresia humilis)高寒草甸沿生境干旱化梯度设置6个样方,采集矮生嵩草根系。采用石蜡切片法,运用方差分析和主成分分析,比较不同土壤水分生境中矮生嵩草一、二级根序解剖结构的差异及可塑性强弱。结果表明：一、二级根序间解剖结构组成无明显差异,其中横切面表皮细胞近似长方形,排列紧密,面积较大(87.6～126.0μm²);一、二级根序解剖结构对生境干旱化的响应不一致,一级根中表皮细胞面积和厚度、皮层厚度(含厚壁组织与薄壁组织)均与土壤含水率呈显著负相关,而二级根呈显著正相关(P<0.05);一级根表皮占径比在土壤水分梯度间的差异显著,其他解剖结构差异不显著,二级根解剖结构(除皮层厚壁组织外)的占径比在土壤水分梯度间均存在显著差异;一级根皮层薄壁组织厚度可塑性最强,皮层厚壁组织厚度可塑性最弱;二级根横切面面积可塑性最强,中柱面积可塑性最弱。总之,矮生嵩草根系表皮、皮层解剖结构对土壤水分梯度变化的可塑性强,但不同根序解剖结构对生境干旱化的响应机制不...     

云南秋海棠属植物叶片横切面比较解剖研究

报道30种主产于云南的秋海棠属植物叶片的横切面解剖构造特征。采用常规石蜡切片法切片观察,结果表明:云南秋海棠属植物叶片薄、横切面均为异面叶、呈典型的阴叶结构,叶肉组织虽有栅栏组织和海绵组织的分化,但栅栏组织不发达,占叶肉组织的比例较小。表皮多为单表皮,极稀复表皮,表皮毛均由多细胞组成。气孔集中于下表皮,孔下室或下陷气孔特大、通气组织极发达;角质层形状多样,呈均匀增厚、瘤状和片状突起;叶绿体椭球形、数多、个体大,主要分布于叶肉组织,集中于栅栏组织。解剖构造特征在各分类组内呈现不完全一致性,而在相同茎的形态类型中有些较一致的特征,在不同种间解剖特征各有差别;根状茎和直立茎类型种类的横切面组织结构表现为表皮细胞壁外的角质层薄、栅栏组织与叶肉组织厚度比例较小等弱光照、湿生等适应性较弱的特征。球茎类型的种类表现为角质层较厚、栅栏叶肉组织厚度比例较大等适应略为干燥和较强光照的特征。     

乌拉尔甘草根与根状茎发育解剖学研究

应用常规石蜡切片方法,对乌拉尔甘草根和根状茎的结构及其发育进程进行研究.结果显示:(1)乌拉尔甘草根的发育包括原分生组织、初生分生组织、初生生长和次生生长4个发育阶段.原分生组织由3层原始细胞组成,具有典型分生组织细胞的特征;初生分生组织由根冠原、表皮原、皮层原和中柱原组成;初生结构包括表皮、皮层和中柱,初生木质部为4原型,偶见3原型,内皮层细胞具凯氏带;次生生长依靠维管形成层和木栓形成层活动完成,维管形成层源于初生木质部和初生韧皮部之间的薄壁细胞,而木栓形成层由中柱鞘细胞脱分化产生;次生结构由次生维管组织和周皮共同组成,根中央不具髓.(2)根状茎发育过程与地上茎类似,包括原分生组织、初生分生组织、初生生长和次生生长4个发育阶段.原生分生组织由原套和原体组成,其衍生细胞分化成由原表皮、基本分生组织和原形成层组成的初生分生组织;初生结构包括表皮、皮层、外韧维管束、髓和髓射线,维管束呈环形排列;位于维管束中的原形成层细胞恢复活动产生次生木质部和次生韧皮部,束间形成层产生射线细胞;靠近维管束内侧的皮层薄壁组织细胞脱分化产生木栓形成层,以后形成周皮.周皮、次生维管束、射线和髓共同构成根状茎的次生结构.     

大花蕙兰营养器官及原球茎的解剖学研究

对大花蕙兰试管苗营养器官及原球茎的解剖学研究结果表明：根由复表皮、皮层和维管柱组成,根毛丰富,皮层发达,内皮层明显,初生木质部月多元型,中央具髓,根茎由表皮,基本组织和维管束构成,维管束散生,属周木型;叶为等面叶,在上下表皮处分布有成束的厚壁组织,叶肉无栅栏组织和海绵组织之分,细胞排列紧密,维管束鞘由机械组织构成。原球茎原生分生组织的原套仅一层细胞,在顶端分生组织后面的薄壁细胞中,存在胚性细胞,由胚性细胞经球状胚可发育成幼原球茎。     

中国干旱区柽柳科植物种子形态特征及其系统学意义

对中国干旱区柽柳科（Ｔａｍａｒｉｃａｃｅａｅ）植物３属７代表种的种子形态及种皮表面亚显微结构进行了观察,表明种子形态及种皮表面亚显微结构可为本科植物的分类提供有价值的信息。根据种子表皮毛着生的类型并结合外部形态特征可初步得出以下结论：（１）表皮毛可分为Ⅰ型表皮毛和Ⅱ型表皮毛,前者着生于种子表面,包括红砂属（ＲｅａｕｍｕｒｉａＬ．）和柽柳属（ＴａｍａｒｉｘＬ．）植物的一些种类;后者着生于种子顶端的芒柱上,包括柽柳属一些种类和水柏枝属（ＭｙｒｉｃａｒｉａＤｅｓｖ．）植物。（２）表皮毛的演化趋势是由Ⅰ型表皮毛向Ⅱ型表皮毛转化。（３）红砂属处于本科的原始地位,水柏枝属较为进化,柽柳属是联系两者的中间环节,本属内亦存在许多过渡类型。     

利用激光扫描共聚焦显微镜研究植物细胞发育形态学变化

通过激光扫描共聚焦显微镜,利用不同种类(波长)的激光研究植物细胞发育形态学变化。结果表明,利用紫外激光(351 nm)扫描可以清楚地观察到拟南芥叶片表皮细胞的形态及其变化,在已分化的叶片表皮上可观察到包括“铺垫”表皮细胞(epidermal pavement cells)、气孔保卫细胞(guard cell)、气孔伴胞(subsidiarycells)、表皮毛细胞(trichomes)和表皮毛的足细胞(socket cells)等多种形态不同的细胞种类;利用蓝光激光(488nm)辅助曙红浅染,可清晰地显示出拟南芥根生长区内部的各种原始细胞,包括静止区(quiescent center)细胞、皮层/内皮层原始细胞(cortex/endodermal initial cell)、表皮/根冠原始细胞(epidermal/root cap initial cell)和中柱/根冠原始细胞(columella/root cap initial cell)等。利用双光子激光(800 nm)连续扫描30 s可以诱发叶绿体产生自发荧光,并可观察到叶绿体在叶肉细胞中的运动轨迹。结果说明激光扫描共聚焦显微镜在植物细胞形态及发育研究上具有独特的功能。     

国产姜科28种植物根解剖结构分析及其系统学意义

对国产姜科(Zingiberaceae)14属28种植物的根进行了解剖结构的比较分析,结果显示:(1)姜科植物的根由外到内均可分为表皮、皮层及维管柱.(2)表皮:一般均由一层表皮细胞组成,大多具表皮毛,表皮细胞轻度木质化.(3)皮层:是由薄壁细胞构成的基本组织,细胞层数较多,少的有15～16层,多的达45层;根据皮层的细胞特点及位置可将皮层分为从内到外的外皮层、中皮层和内皮层.其中:外皮层由1～9层不等的薄壁细胞组成,细胞排列紧密,无间隙,胞壁略栓质化;构成中皮层的细胞或为大型薄壁细胞,细胞不规则,含少量淀粉粒;或为大中型、圆形、椭圆形或不规则形,含大量淀粉粒、方晶等晶体;或为小型薄壁细胞,一般圆形至椭圆形、方形、长方形.中皮层均有油细胞分布;内皮层均由一层细胞构成,大多数具U-形增厚.(4)维管柱:一般由中柱鞘、维管组织和髓组成.其中:中柱鞘由一层与内皮层平行排列的薄壁细胞构成,细胞略切向延长;木质部脊数为多原型;一般具髓,但髓在组织构成和后含物的有无方面存在差异.(5)本研究结果支持依据分子证据将原姜科4族划分为2亚科的结论,但对其各亚科所涵盖的族和属的范围不完全支持,特别是不支持将原姜花族、舞花姜族和姜族放在一起称为姜亚科的观点;在族级水平方面,姜属植物根在上述特征上具有较高的一致性,且与其它类群界限清楚,因而根的解剖学特征也倾向于支持姜族独立.     

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.     

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.     

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。     

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.     

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.