香溪河小水电的梯级开发对浮游藻类的影响

以香溪河干流上5个连续的小水电站为对象,于2005年10月20—22日分别对其浮游藻类和主要理化指标进行研究.结果表明：硅藻占绝对优势(95.54%),其中,线性曲壳藻(Achnanthes linearis)、披针曲壳藻椭圆变种(A. lanceolata var. elliptica)、扁圆卵形藻(Cocconeis placentula)为绝对优势种,其平均相对丰富度分别为23.96%、18.62%和12.48%;所有样点的平均藻类密度为6.29×10⁵ ind·L^-1,最高为1.81×10⁶ ind·L^-1,最低为2.35×10⁵ ind·L^-1.方差分析表明,流速变化是小水电站开发影响河流中浮游藻类的主要原因.电站取水坝的建立,使其下游生境(生境3)与其它4个生境显著不同,导致多个参数出现骤变,包括Margalef多样性指数、物种丰富度、属的丰富度、硅藻组成、硅藻百分含量等均受到显著影响.     

黄河上游玛曲段春季浮游生物群落结构特征

为了了解黄河上游玛曲段的水质状况,于2006年4—5月对黄河玛曲段干流浮游生物的群落组成进行了调查。结果表明：全段的浮游植物共有5门23种（属）,浮游植物密度为3.2×10⁴～54×10⁴ cells·L^-1,平均密度为19.7×10⁴ cells·L^-1,生物量为0.069～0.464 mg·L^-1,平均生物量为0.228 mg·L^-1,其中密度最高的为齐哈玛,生物量最高的为玛曲大桥;浮游动物共有2门10种（属）,密度为670～1273 cells·L^-1,平均为881.56 cells·L^-1,生物量为0.044～0.089 mg·L^-1,平均为0.064 mg·L^-1;该河段浮游生物组成多以冷水性为主;浮游植物多样性指数介于2～3,表明黄河上游玛曲段水质呈轻度污染;浮游生物丰富度与均匀度值均较低,群落结构组成不稳定,易受外界环境的干扰。     

酸雨对温州三土羊湿地水体氮营养盐数量的影响

为了解酸雨对温州三羊湿地水体氮营养盐数量的影响,本文测定了三土羊湿地水体中不同形态氮的含量,其中氨氮2.90～10.75 mg·L^-1,平均538 mg·L^-1、硝态氮0.16～0.44 mg·L^-1,平均0.31 mg·L^-1;总氮34.04～63.20 mg·L^-1,平均55.75 mg·L^-1和水体的pH值,6.1～6.5,平均6.4;并测算了近两年通过降水输入到三羊湿地和三羊湿地水体中不同形态氮的数量及其占湿地现有水体中各形态氮的比例,其中输入到三羊湿地氨氮、硝态氮和总氮的量分别为2.48～2.86×10⁴ kg、2.87×10⁴～4.96×10⁴ kg和5.35×10⁴～7.82×10⁴ kg,分别占湿地水体现有量的56%～64%、11.21～19.38倍和12%～17%;直接输送到三羊湿地水体各形态氮的数量0.72×10⁴～0.84×10⁴ kg、0.83×10⁴～1.44×10⁴ kg和1.55×10⁴～2.27×10⁴,分别占现有量的16%～19%,3.24～5.63倍和3%～5%.结果表明,酸雨是三,羊湿地水体氮污染的主要来源之一,对三羊湿地水体富营养化产生重要影响.     

食物密度对镜湖萼花臂尾轮虫不同克隆生活史特征的影响

对镜湖萼花臂尾轮虫（Brachionus calyciflorus）夏季种群内4个生化遗传特征上互不相同的克隆（克隆A、B、C和D）在4个斜生栅藻（Scenedesmus obliquus）密度（1.0×10⁶、2.0×10⁶、4.0×10⁶和8.0×10⁶ cells·L^-1）下的生活史特征进行了研究.结果表明：食物密度对各克隆轮虫的存活率和繁殖率均有不同的影响.4克隆中克隆C的世代时间最短,克隆B的世代时间、生命期望和平均寿命最长,克隆A的后代混交雌体百分率最高;净生殖率和个体适合度在4克隆间无显著差异.镜湖萼花臂尾轮虫在2.0×10⁶ cells·L^-1的食物密度下净生殖率最低;在1.0×10⁶cells·L^-1的食物密度下平均寿命和生命期望最短,而后代混交雌体百分率却最高;在8.0×10⁶cells·L^-1的食物密度下种群内禀增长率最高,平均寿命和生命期望最长;在高食物密度（4.0、8.0×10⁶cells·L^-1）下个体适合度较大.克隆C的个体适合度在密度为3.9×10⁶cells·L^-1时最小,而克隆D的个体适合度在食物密度为6.34×10⁶cells·L^-1时最大.食物密度的变化可能是7月份之后镜湖萼花臂尾轮虫从水环境中消失的原因,而4克隆轮虫个体适合度的相似性则可能是镜湖轮虫共存于同一水体的原因之一.     

光萼荷属植物SSR反应体系确立与指纹图谱构建

利用正交试验设计优化并确立光萼荷属（Aechmea）植物SSR反应体系,构建部分光萼荷属植物的SSR分子指纹图谱。结果表明：光萼荷属植物的最佳SSR反应体系为10 μL总体积包括1×PCR buffer、Mg²⁺ 2.0 mmol·L^-1、dNTPs 200 μmol·L^-1、引物2.5 μmol·L^-1、模板DNA 90 ng和Taq DNA聚合酶1.5 U。利用该体系和6对SSR引物对15份光萼荷属植物进行扩增反应和电泳检测,其中M1、M3、M4等3对SSR引物扩增图谱清晰、多态性较高,均能将该15份光萼荷属植物鉴别出来,初步建立了15份光萼荷属植物的SSR分子指纹图谱,进一步证明该SSR反应体系稳定可靠,可以有效用于光萼荷属植物种质资源鉴定。     

香蕉基因组SRAP反应体系的建立和优化

为建立并优化适于香蕉（Musa spp.）SRAP分析的扩增体系,对影响香蕉SRAP反应的dNTP、Mg²⁺、模板DNA、引物浓度和Taq酶用量等因素进行优化。确定的优化扩增体系为Mg²⁺ 2.5 mmol·L^-1,dNTP 250 μmol·L^-1,Taq酶1.0 U,引物0.5 μmol·L^-1,模板DNA 20 ng,10×PCR buffer 2.5 μL,在此条件下SRAP扩增香蕉基因组DNA条带清晰,多态性丰富。该体系在29个香蕉基因组中获得较好的扩增结果,可望在香蕉植物起源和进化研究中应用。     

深圳红树林湿地浮游植物多样性的组成与分布

根据深圳福田红树林湿地的浮游植物周年调查资料,分析浮游植物群落多样性的组成与时空分布特征,并利用浮游植物群落多样性指数对湿地水体的营养状态进行评价。共记录浮游植物5门28属51种,各季度浮游植物数量均超过10.6 ind·L^-1。硅藻分布广泛,在种类和数量上均占主导地位,优势种为微小小环藻（Cyclotella caspia）和诺氏海链藻（Thalassiosira nordenskiöldi）等,耐受污染的藻类,如小颤藻（Oscillatoria minima）、鱼形裸藻（Euglena pisciformis）在夏秋2季成为个别站位的优势种。浮游植物种类组成时空变化明显,而数量的空间变化较大、季节变化不大,优势种的时空变化明显,但种类单一,多样性指数的空间变化较大。群落多样性指数评价结果显示,深圳红树林湿地处于中-富营养化状态,有向富营养化过渡的趋势,应加强对内陆径流和污水排放进入红树林湿地的严格控制和管理。     

利用正交设计优化小苍兰ISSR-PCR反应体系

通过L₁₆(4⁵)正交试验，研究了镁离子浓度、dNTP浓度、模板DNA浓度、Taq DNA聚合酶浓度、引物浓度这5个因素在4个水平上对ISSR-PCR的影响，建立了适合于小苍兰ISSR-PCR的反应体系。优化体系为：25 μL PCR反应体系中含有1×Taq酶缓冲液(10 mmol·L^-1 KCl，8 mmol·L^-1(NH₄)₂SO₄，10 mmol·L^-1 Tris·HCl，pH 9.0，0.05% NP-40)，2 mmol·L^-1 MgCl₂，0.06 U·μL^-1 Taq酶，0.4 μmol·L^-1引物，4.0 ng·μL^-1模板DNA，dATP、dCTP、dGTP、dTTP各0.6 mmol·L^-1。利用温度梯度PCR，确定了最适宜的退火温度为51.5℃。该优化体系的建立为下一步对小苍兰进行ISSR分子标记奠定了基础。     

廊坊杨3号快繁和转基因的再生系统

对杂交杨树新品种廊坊杨3号（Populus langfangensis 3,(P. deltoides (“Shan Hai Guan”)×((P. simonii × pyramidalys)₁₂×Ulmus pumila) 的离体叶片和茎段在附加BA、NAA、IBA和2,4-D的MS培养基上的直接和间接的器官分化、愈伤组织形成和植株再生进行了研究。叶柄和叶片最容易在叶脉处直接诱导生芽。从叶片直接诱导生芽的激素条件为1～2 mg·L^-1 BA和0.5 mg·L^-1 IBA,最高生芽率可达90%。2,4-D促进愈伤组织的形成。由愈伤组织诱导生芽的激素条件为0.3～0.5 mg·L^-1 BA 和 0.02 mg·L^-1 IBA或NAA,生芽率达76%。较好的生根条件为0.1 mg·L^-1 BA和0.2～0.5 mg·L^-1 IBA,生根率可达67％。以上再生条件为廊坊杨3号的转基因育种和无性快繁技术提供了可能。     

南极长城站地区土壤微生物生态作用的初步探讨

从南极长城站附近联合采样13个,并进行了土壤微生物的数量统计与种类鉴定。氨化细菌的菌量为10⁴～10⁶cells／g,共7个属：微球菌属（Micrococcus）,葡萄球菌属（Staphylococcus）,假单胞菌属（Pseudomonas）,芽孢杆菌属（Bacillus）,产碱菌属（Alcaligenes）,黄杆菌属（Flavobacterium）,节杆菌属（Arthrobacter）;固氮细菌菌量为10⁵～10⁷cells／g,仅一个固氮菌属（Azotobacter）;硝化细菌一般为10⁴cells／g,分属两个属：硝化杆菌属（Nitrobacter）,硝化球菌属（Nitrococcus）;真菌为10³cells／g,分属5个属：青霉菌属（Penicillium）,金孢霉菌属（Chrysosporium）,枝孢霉菌属（Cladosporium）,曲霉菌属（As-pergillus）,散囊菌属（Eurotium）,反硝化菌为 10²～10⁴cells／g,分属 3个属：假单胞菌属（Pseudomonas）,微球菌属（Micrococcus）,芽孢杆菌属（Bacillus）;放线菌分属3个属：链霉菌属（Streptomyces）,小单孢菌属（Micromonospora）,和诺卡氏菌属（Nocardia）。联采样品12℃培养的出现率主要类群是：假单胞菌属（42％）,芽孢杆菌属（35％）,微球菌属（31％）,节杆菌属（27％）,青霉菌属（58％）,枝孢霉菌属（54％）,硝化杆菌属（81％）,固氮菌属（88％）,反硝化细菌中主要是假单胞菌属（58％）,芽孢杆菌属（38％）。文中还讨论了微生物菌量与土壤总碳、总氮的相关性及其在该地区氮循环中的生态学作用。     

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.     

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.     

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.     

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.     

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。     

Time of detection of recessive genes: effects of system of mating and number of examined individuals

Summary Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, Siete Cerros 66 and Penjamo 62, as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of Penjamo 62 in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed.