CO2 浓度变化对两种淡水绿藻的显微结构和超微结构的影响

为了探讨淡水绿藻在适应CO2浓度变化过程中细胞形态和结构的变化,通过普通显微镜和电子显微镜观察了在不同CO2浓度培养下的莱因衣藻(Chlamydomonas reinhardtii Dang)和斜生栅藻(Scenedesmus obliquus Kütz)细胞.结果表明,CO2浓度变化对莱因衣藻细胞体积没有明显的影响,但斜生栅藻在低浓度CO2培养下细胞体积明显增大,并可见细胞内含有大量颗粒.两种绿藻细胞的超微结构显示,在低浓度CO2培养下,细胞内叶绿体数目明显减少,并可见明显的淀粉盘包围的蛋白核;细胞内还可见大量的淀粉粒.而在高浓度CO2培养下,这两种绿藻细胞内均未见明显的蛋白核和大量淀粉粒出现.     

CO2浓度变化对两种淡水绿藻的显微结构和超微结构的影响

为了探讨淡水绿藻在适应CO2党旗变化过程中细胞形态和结构的变化,通过普通显微镜和电子显微镜观察了在不同CO2浓度培养下的莱因衣藻（Chlamydomonas reinhardtii Dang）和斜生栅藻（Scenedesmus obliquus Kuetz）细胞。结果表明,CO2浓度变化对莱因衣藻细胞体积没有明显的影响,但斜生栅藻在低浓度CO2培养下细胞体积明显增大,并可见细胞内含有大量颗粒,两种绿藻细胞的超微结构显示,在低浓度CO2培养下,细胞内叶绿体数目明显减少,并可见明显的淀粉盘包围的蛋白核;细胞内还可见大量的淀粉粒。而在高浓度CO2培养下,这两种绿藻细胞内均未见明显的蛋白核和大量淀粉粒出现。     

梭鱼草化感物质丁二酸对微囊藻和栅藻生长及竞争的影响

为了解梭鱼草(Pontederia cordata)根茎有机酸类化感物质对铜绿微囊藻(Micro-cystis aeruginosa,M)和斜生栅藻(Scenedesmus obliquus,S)生长和竞争关系的影响,将不同浓度丁二酸作用于两种藻的单种培养和共培养,即铜绿微囊藻与斜生栅藻初始比例为1∶0(100%M)、1∶1(50%M+50%S)、2∶3(40%M+60%S)、3∶2(60%M+40%S)、0∶1(100%S)。结果表明:丁二酸对铜绿微囊藻和斜生栅藻均有抑制作用,抑制能力与浓度呈正相关;无化感物质作用下,单种培养和共培养中铜绿微囊藻生长能力均强于斜生栅藻; 60mg·L-1丁二酸处理下,40%M+60%S、50%M+50%S培养组中β(斜生栅藻对铜绿微囊藻的抑制参数)0,60%M+40%S培养组中β0,表明藻类初始比例影响蓝绿藻之间竞争;丁二酸可改变蓝绿藻之间竞争关系,低浓度(20、40 mg·L-1)作用下,表现为铜绿微囊藻抑制斜生栅藻,斜生栅藻促进铜绿微囊藻,高浓度(60、80 mg·L-1)作用下,表现为两者相互抑制,表明两种藻之间竞争加强。     

极高CO2胁迫对被甲栅藻(Scenedesmus armatus)生理活性和细胞结构影响

以被甲栅藻(Scenedesmus armatus)为材料研究极高浓度CO2对其生理活性和细胞结构的影响.研究表明,被甲栅藻能在60%的CO2浓度下快速生长,在5%、20%、40%、60%、80%、100% CO2浓度下的平均增长率分别是1.228、0.925、0.741、0.305、0.042、0.001 g·L-1·d-1 DW.通入极高浓度CO2(20%、40%)后,被甲栅藻细胞的光系统II(PSII)最大光化学效率(Fv/Fm)在24 h内明显下降,对PSII抑制作用较明显;其后,随培养时间的增长而逐渐恢复正常.显微结构和亚显微结构显示极高CO2浓度下培养了6 d的藻细胞体积稍膨大、颗粒化,色素体结构相对不完整,类囊体膜结构略显松散,蛋白核消失,细胞内的液泡数目增多.     

6种微藻对氯霉素和硫酸新霉素敏感性研究

目的:探讨3种真眼点藻(点状魏氏藻(Visderia punctata)、波氏真眼点藻(Eustigmatos polyphem)、魏氏真眼点藻(Eustigmatos vischeri))和3种绿藻(栅藻(Scnedesmus sp.)、斜生栅藻(Scenedesmus obliqulis)、爪哇栅藻(Scenedesmus jaoaensis))对2种抗生素的敏感性.方法:采用藻液细胞计数法和藻细胞固体平板培养法研究了氯霉素和硫酸新霉素对6种微藻生长的影响.结果:液体培养,3种绿藻对氯霉素敏感性均高于硫酸新霉素,10μg·mL-1氯霉素即可明显抑制3种绿藻的生长(P＜0.05),而硫酸新霉素在浓度为200 μg·mL-1时才显示出明显抑制作用:3种真眼点藻对2种抗生素都不敏感.固体培养,除波氏真眼点藻外,其它5种微藻对氯霉素的致死浓度均为50μg·mL-1;波氏真眼点藻、栅藻、斜生栅藻和爪哇栅藻对硫酸新霉素的致死浓度分别为100 μg·mL-1、200μg· mL-1、50μg·mL-1和50μg·mL-1.结论:氯霉素可作为选育6种微藻抗性突变株的筛选剂.     

斜生栅藻对振荡和磷胁迫的生理生化响应

为了探讨水文条件的变化对常见绿藻水华发生的潜在影响,实验以斜生栅藻为材料,研究了不同水流状态及磷浓度对其生长及磷利用策略的影响。实验分别设置静止条件(0 r/min)、低振荡条件(90 r/min)和高振荡条件(120 r/min),同时设置磷限制(0.2 mg/L)和磷充足(2 mg/L)两组磷浓度,整个实验过程为3周。实验过程测定的指标为:比生长速率、胞外碱性磷酸酶活性、叶绿素a含量以及磷吸收动力学参数。实验结果表明:(1)同静止条件相比,低振荡和高振荡条件均能显著降低斜生栅藻的比生长速率,但是两种不同磷浓度下其比生长速率却无显著性差异。(2)在实验第21天时,振荡条件培养下,斜生栅藻的胞外碱性磷酸酶活性显著高于静止条件培养,与此相反,胞内磷浓度却显著高于静止条件。(3)在磷限制条件下斜生栅藻的叶绿素a含量显著降低,同时两种振荡条件培养均使其在磷充足条件下叶绿素a含量降低。(4)通过磷吸收动力学参数的比较,静止条件培养的斜生栅藻对磷的亲和力高于其在振荡条件下。由此可见,斜生栅藻适应于静止无扰动且磷营养丰富的水体,随着水体中磷浓度进一步升高,静止和水流缓慢的水体存在导致像斜生栅藻这一类绿藻发生水华的风险。       

重金属铅与两种淡水藻的相互作用

为了研究重金属铅与淡水藻类之间的相互作用,采用不同Pb2+浓度处理铜绿微囊藻(Microcysis aeruginosa Kutz.)和斜生栅藻[Scenedesmus obliquus(Turp.)Kutz.],分别对两种藻的生物量、藻液电导率、O-·2含量、过氧化物酶(POD)、过氧化氢酶(CAT)活性以及藻对Pb2+的吸收作用等进行了测定,并通过扫描电镜观察了不同Pb2+浓度处理下两种藻细胞的表面结构。结果显示:(1)Pb2+浓度低于3 mg/L促进铜绿微囊藻生长,高于9 mg/L抑制其生长;但在3—12 mg/L范围内,Pb2+均明显抑制了斜生栅藻的生长,说明斜生栅藻对Pb2+毒性的敏感程度要高于铜绿微囊藻。(2)受到铅离子的胁迫,两种藻细胞膜通透性均有一定改变,扫描电子显微镜的照片观察,两种藻细胞表面的絮状物随着Pb2+的升高而增多,尤其是斜生栅藻细胞结构改变明显,多数细胞变形破裂;同时,O-·2含量升高,POD、CAT活性早期均可随Pb2+的增加而上升,表明氧自由基的产生增多以及由其引起的细胞生理生化改变可能是铅离子作用于藻细胞的主要机制。(3)两种淡水藻对Pb2+均有吸收作用,单位量藻细胞内,斜生栅藻对Pb2+的吸收能力好于铜绿微囊藻。所有结果提示:斜生栅藻不仅可以作为对重金属敏感的指示生物来监测水体Pb2+污染程度;同时由于斜生栅藻比铜绿微囊藻具有更好的Pb2+吸收能力,因此还可以利用斜生栅藻作为处理水体Pb2+的生物材料。     

斜生栅藻对不同形态锑胁迫的响应及抗性研究

该研究以斜生栅藻(Scenedesmus obliquus)为研究对象,研究不同浓度的Sb(Ⅲ)、Sb(Ⅴ)胁迫下对斜生栅藻生长速率、叶绿素a、抗氧化酶活性和细胞表面结构的影响,以探讨重金属胁迫下斜生栅藻的抗性机理。结果表明:(1)在高浓度Sb(Ⅲ)、Sb(Ⅴ)胁迫处理中,斜生栅藻生长对Sb(Ⅲ)胁迫的响应更加迅速;随着Sb(Ⅲ)、Sb(Ⅴ)胁迫浓度增加,斜生栅藻体内叶绿素a含量呈下降趋势,且对Sb(Ⅲ)胁迫浓度的变化反应更为敏感。(2)在800μmol/L Sb(Ⅲ)和Sb(Ⅴ)胁迫下,斜生栅藻体内丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性分别在胁迫第7~8天和第6~7天时变化更为明显;过氧化氢酶(CAT)活性在胁迫处理的第4~5天就迅速增加,对Sb胁迫响应比SOD更为迅速。(3)在高浓度Sb(Ⅲ)、Sb(Ⅴ)胁迫下,斜生栅藻细胞结构受到严重损伤,而且Sb(Ⅲ)对斜生栅藻细胞的损伤更加明显。研究发现,Sb(Ⅲ)、Sb(Ⅴ)对斜生栅藻生长、叶绿素a及细胞结构表现出不同程度的抑制和破坏作用,其细胞受到的影响程度与Sb(Ⅲ)、Sb(Ⅴ)的处理浓度及处理时间均密切相关,但斜生栅藻依靠自身抗氧化酶系统在一定程度上能够缓解Sb胁迫的不利影响。     

水芹水浸提液对斜生栅藻的化感效应研究

采用栅藻在不同浓度的水芹水浸提液中纯培养的方法,研究了水芹水浸提液对斜生栅藻细胞数、叶绿素含量及藻细胞超微结构的影响。结果显示,10 g·L^-1水芹水浸提液对斜生栅藻的生长和叶绿素含量的增加具有明显的促进效应;20 g·L^-1水芹水浸提液对藻细胞数和叶绿素含量的增加持续到第3 d,3 d后出现显著的抑制效应;高浓度（30~50 g·L^-1）水芹水浸提液对藻细胞数和叶绿素含量的明显抑制在第2 d始现,随时间延长而加剧,并具有浓度效应;40 g·L^-1水芹水浸提液处理后,斜生栅藻细胞壁断裂甚至消失,细胞中叶绿体片层肿胀甚至解体,核膜破裂,核质外渗。水芹水浸提液对斜生栅藻具有化感效应,低浓度促进生长,高浓度抑制。     

CO2浓度升高对斜生栅藻生长和光合作用的影响

升高大气中CO2 浓度可提高斜生栅藻的生物量和光合作用速率 ,对光合效率、暗呼吸速率、光饱和点和光系统Ⅱ的光化学效率 (Fv Fm)没有明显影响 ,但藻细胞光合作用对无机碳的亲和力降低     

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.     

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.     

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.     

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。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

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.