温度和盐度对蒙古裸腹Sou种群内禀增长能力的影响

报道了蒙古裸腹Sou(Moina mongolica)在20℃-33℃温度和5－40ppt盐度条件下和种群内禀增长率（rm),结果表明,20℃-30℃范围内蒙古裸腹Sourm随温度升高,超过30℃后继续升高,rm显著降低,在低盐度下蒙古裸腹Sou的种群增长能力相对较强,盐度为10ppt时rm最高,20－40ppt范围内Sou的rm差别不明显,本实验表明,25℃-30℃和10ppt分别是蒙古裸腹Sou种群增长较快的温度和盐度条件,在海水中长期培养对蒙古裸腹Sou的种群增长能力不会产生明显的不良影响。     

多刺裸腹溞在不同盐度下的种群增长参数及其驯化

在25±1℃及小球藻、酵母、牛粪+稻草+沃土3种食物条件下,研究了多刺裸腹溞在海水盐度为2‰、3‰、4‰、6‰和淡水5个浓度下的种群增长参数.实验表明无论投喂何种食物,在淡水至4‰盐度范围内,多刺裸腹溞种群的内禀增长率(rm无显著差异为0.725-1.070(d-1);净增殖率(Rn)以小球藻组平均数最高为55.13(ind.);世代时间(T)以酵母组最长,平均为5.38(d).6‰为多刺裸腹溞的生殖盐度上限.经过短期的海水驯化,其生殖的盐度上限可达9-10‰.     

中华绒螯蟹Eriocheir sinensis H.Milne-Edwards的幼体发育

1.本文所报道毛蟹的幼体发育试验,全部是在实验室内进行的。 2.毛蟹的幼体发育共经五个(氵蚤)状幼体期和一个大眼幼体期。卵孵化出膜的幼体即为第一(氵蚤)状幼体,而不是早期(氵蚤)伏幼体或原(氵蚤)伏幼体。这两种幼体应该是在卵膜内度过的。 3.在水温11—22℃,盐度为9‰的实验室条件下,从幼体出膜到第一期幼蟹的出现,共经39—40天。每蜕一次皮,即进入另一发育时期,其所需的时间,随着温度的升高而缩短。其发育速度见下表: 幼体名称 水温(℃) 日数 第一(氵蚤)状幼体 11—17 7—9 第二(氵蚤)状幼体 17—18 5—6 第三(氵蚤)状幼体 18—20 6—7 第四(氵蚤)状幼体 16—19.5 5—6 第五(氵蚤)状幼体 16.5—19 7—8 大眼幼体 19—22 9—10 4.饵料、盐度、水温和水质等因子对幼体有着不同程度的影响。 5.(氵蚤)状幼体以两对颚足外肢末端的羽伏刚毛的数目,胸、腹肢的大小与形状和尾叉内面中部刚毛的数目为分期的主要依据。     

近亲裸腹溞对海水盐度的适应性

为了解淡水枝角类对海水盐度的适应性,在实验室内采用种群实验生态学方法研究25 ℃±0.5 ℃恒温条件下不同盐度（0、1、2、3、4、5）对近亲裸腹溞(Moina affinis)生存、生长和生殖的影响.结果表明,在各盐度梯度范围内,近亲裸腹溞的平均寿命随盐度升高而缩短,盐度4和5组内禀增长率与其它各组差异显著;盐度4和5组平均每窝产幼量与对照及其他组差异显著.一生产幼量除盐度1组和对照组较高外,其他各组均显著下降.对照组体长增长幅度与日增长率均低于各处理组.日增长率随着盐度的升高而增大.个体平均每胎产幼量以盐度1、2组最高.盐度5为近亲裸腹溞的生存和生殖盐限,但经过短期的海水驯化,其生殖耐盐上限有所提升,可达6.5.     

共培养大型海藻对蒙古裸腹溞培养体系的生态效应

为了解大型海藻与盐水枝角类共培养的生态作用,通过大型海藻与蒙古裸腹溞共培养的方法,研究了孔石莼和肠浒苔对共培养水体水质的静态净化效果以及对该溞生殖与种群增长的影响。结果表明:孔石莼和肠浒苔对共培养水体氨氮(NH3-N)、pH和溶解氧(DO)的影响显著(P0.05)且变化规律基本一致,其中NH3-N在第12 d降到最低(0.016mg·L~(-1)),随后维持在相对稳定范围内; pH和DO随孔石莼和肠浒苔生物量的增加而升高,pH变化范围8.2～9.0,DO变化范围4.2～6.4 mg·L~(-1);共培养条件下两种大型海藻对蒙古裸腹溞生殖和种群增长的影响表现出明显差异,在孔石莼共培养体系中,蒙古裸腹溞的平均生殖量、内禀增长率rm、周限增长率λ和世代周期T随孔石莼生物量的增加呈波动升高,当生物量为2.5 g·L~(-1)时均达峰值,之后逐渐下降,平均寿命随孔石莼生物量的增加而减少;孔石莼共培养体系显著优于对照组单一蒙古裸腹溞培养效果(P0.05),而肠浒苔共培养体系与对照组相差不显著(P0.05)。研究结果证明了孔石莼对共培养体系水质和养殖动物的有利作用,即共培养一定生物量(2.5～3.5 g·L~(-1))的孔石莼不但有利于培养水体中NH3-N、DO等水质净化,还可以促进蒙古裸腹溞的生长与繁殖,为蒙古裸腹溞规模化培养工艺优化与新模式构建提供了科学依据。     

温度对美洲斑潜蝇种群参数的影响(英文)

本文报道温度对美洲斑潜蝇种群参数和自然内禀增长率的影响。实验在 5种温度即 15,2 0 ,2 5,30和 35℃ ,相对湿度为 80 % ,光照 12∶12 (L∶D)条件下进行 ,并用菜豆Phaseolusvulgaris作为它的寄主植物。实验结果表明 ,美洲斑潜蝇非成熟期的发育时间从 15℃的 38d减少到 35℃的 11d。描述卵 ,幼虫和蛹的发育率 (y)随温度 (t)变化的方程分别是 y =1 786 2t - 13 84 1,y =1 16 2t - 4 94 6和 y =0 6 34t - 5 146。雌成虫的寿命在 15℃条件下是 2 0d ,到 35℃时则下降到 9d。最适宜的繁殖温度是 2 0℃- 30℃ ,在此温度范围内每雌产卵量为 158粒到 2 82粒。非成熟期在 2 5℃条件下的死亡率最低 ,为9% ,而最高出现在 35℃ ,为 4 9%。在 2 5℃到 30℃这个温度范围内 ,获得较高的自然内禀增长率(rm)和净繁殖力 (R0 ) ,分别为 0 2 7和 116 8,此结果表明此温度范围最有利于该种群的增长 ,种群的世代增长倍数约为 117倍。实验结果还表明 ,该虫种群的平均世代历期 (T)和种群倍增时间 (t)随温度升高而减少 ,而种群有限增长率 (λ)与温度的关系则是正的线性关系。     

蒙古裸腹溞与褶皱臂尾轮虫的种间关系

在实验室内将蒙古裸腹溞按0．06、0．10、0．30、0．60个·ml^-1的密度与褶皱臂尾轮虫(密度为0．3个·ml。)进行}昆合培养,同时按上述密度分别单种培养了蒙古裸腹溞和褶皱臂尾轮虫作为对照．结果表明,蒙古裸腹溞与褶皱臂尾轮虫之间存在种间竞争,当二者共存时,褶皱臂尾轮虫对蒙古裸腹溞种群产生压制作用,使蒙古裸腹溞在混合培养体系中以很低的密度存在,而褶皱臂尾轮虫种群受蒙古裸腹溞影响不大．通过进一步的饥饿实验发现90％的褶皱臂尾轮虫经过144h饥饿后仍然存活,而经过120h饥饿后的蒙古裸腹溞100％死亡,褶皱臂尾轮虫耐饥饿能力较强是其在与蒙古裸腹溞竞争中获胜的原因之一。     

生态因子的波动对多刺裸腹溞雄体发生的影响

采用克隆培养法,研究了几种主要生态因子的波动对多刺裸腹氵蚤雄体发生的影响和该氵蚤对上述生态因子波动的敏感程度.结果表明,无论是一次性剧烈刺激,还是持续性渐进刺激,该氵蚤均未能直接产生雄体,即氵蚤的孤雌生殖雌体不能直接转变为混交雌体(两性生殖雌体);在光照、温度、饵料密度、pH值持续性渐进波动时,该氵蚤种群的内禀增长率分别为0.7748、0.7481、0.6539和0.6310d-1ind-1,比对照组降低0.9%、4.0%、16.4%和19.3%,表明该氵蚤对饵料密度和pH值的波动较为敏感,对温度的敏感性次之     

可口革囊星虫胚胎与幼体的发育

解剖经降温8-10℃刺激30-40h后的可口革囊星虫(Phascolosomaesculenta)亲体取得精、卵,用人工授精法获得的受精卵进行胚胎和幼体发育的研究。结果表明:可口革囊星虫的卵为圆形或椭圆形,卵的大小为120μm×142μm-125μm×148μm。精子由头部、中段和尾部组成,全长约为32-40μm。在海水盐度23.8ppt、pH8.1、温度15℃的条件下,精、卵不能受精;在海水盐度23.8ppt、pH8.1、温度20℃的条件下,精卵能受精,但胚胎发育到原肠胚期停止;在海水盐度23.8ppt、pH8.1条件下,25℃、30℃和35℃的不同水温,精卵均能受精,受精卵发育到初期海球幼虫分别需要72h0min、47h08min和42h53min。在海水盐度23.8-25.5ppt,pH8.1-8.2,温度28-30℃条件下,从初期海球幼虫发育到稚虫需要15-20d。     

“培养液中酵母菌种群数量的变化”实验研究

在20℃、25℃和30℃3个温度,0、10%、20%和40%4个土豆浓度以及0、2%、5%和8%4个葡萄糖浓度条件下,通过三因素交互实验,发现酵母菌在25℃、8%葡萄糖浓度和40%土豆浓度组合条件下种群数量增长率最高;在20℃、5%葡萄糖浓度和20%土豆浓度,20℃、8%葡萄糖浓度和10%~20%土豆浓度,30℃、8%葡萄糖浓度和10%~40%土豆浓度等组合条件下种群数量呈"S"型增长,适合进行数学建模教学。     

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.     

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.     

（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。