多效唑对欧李试管苗生长和生根的影响

欧李(Cerasus humilis Bunge,又名钙果)试管苗设置两组实验:(1)继代繁殖时,以MS为基本培养基,附加0.4mg·L-16-BA、0.04mg·L-1NAA、30g·L-1蔗糖和7g·L-1琼脂,加不同浓度多效唑,培养28d后,调查试管苗繁殖系数、嫩梢长度,观察茎杆细胞形态;(2)诱导生根时,以MS为基本培养基,附加3.0mg·L-1IAA、20g·L-1蔗糖和7g·L-1琼脂,加不同浓度多效唑,于温度(20±3)℃、光强约50μmol·m-2·s-1、10￣12h·d-1光照下,培养20d,调查生根情况。获得如下结果:1.加0.1mg·L-1多效唑的繁殖系数和嫩梢长度稍低于不加多效唑的;多效唑浓度超过0.1mg·…     

松嫩平原羊草草原凋落物层群落学作用的研究

 植物的萌发数量与凋落物量呈抛物线型,峰值出现在200g·m-2处,凋落物对植物萌发影响主要是通过影响地表温度和土壤水分而起作用。群落的物种数随着凋落物量增加而增加,峰值出现在800g·m-2处,种饱和度达14种·m-2,峰值后略有下降。群落优势种羊草(Aneurolepidium chinense)的密度、平均高度、盖度和地上生物量随凋落物量的变化趋势基本相同,峰值出现在600g·m-2左右。凋落物层对群落的演替动态有一定的影响,凋落物量相近的样地差异较小,随着凋落物量的增加,群落间差异越来越大。群落地上和地下生物量随凋落物量的变化呈单峰曲线,地上生物量峰值出现在600g·m-2处,地下生物量出现在700g·m-2处,地下生物量/地上生物量值随凋落物量变化呈V字型,最小值出现在550g·m-2左右。     

多效唑对不同立地条件下黄荆生长及生理特征的影响

该试验以绿化卷材为基质材料,对沙场、渣场和混凝土屋面3种立地条件下生长的黄荆进行不同浓度(0、100、200、300、400mg·L~(-1))多效唑处理,研究根施多效唑对黄荆生长和生理特征的影响以及不同立地环境的应用差异。结果显示:(1)随多效唑浓度升高,3种立地类型黄荆株高和生物量呈降低趋势,冠幅、基径、叶面积、根幅、主根长和主根径呈减小趋势,叶片长宽比和根冠比表现出增大的趋势;多效唑处理使黄荆叶片相对含水量、叶绿素含量、可溶性糖和可溶性蛋白含量增加,使丙二醛含量下降。(2)不同立地条件下黄荆对多效唑处理的表现具有一定差异,隶属函数法综合评价显示,对沙场、渣场和屋面3种立地类型的黄荆生长调控效果最佳的多效唑浓度分别为400mg·L~(-1)、300mg·L~(-1)、100mg·L~(-1)。(3)当多效唑浓度在渣场和屋面分别为400、300mg·L~(-1)时,黄荆叶片开始受到伤害,对多效唑的耐受阈值表现为沙场渣场屋面。研究认为,多效唑可有效调控黄荆的形态和生物量分配,增强细胞渗透调节和抗氧化损伤能力,从而提高黄荆的抗逆性和环境适应性,但在应用时应考虑不同立地背景的差异,因地制宜地选择使用浓度和用量,使其更好地应用于人工植被恢复与建设。     

中国东北羊草草原生长季内产量生态模拟及信息参数应用

通过对中国北方羊草草原生物量动态、生物量垂直空间格局及其与环境因子相互关系等主要产量生态数量特征的模拟与内在相关性的研究 ,结果表明 ,草地地上生物量的生长规律呈“单峰”型 ,最大地上生物量出现在 8月 5日 ,其值为1 97.3g· m- 2 干物质 ,而后下降 ;在达到峰值前 ,符合 logistic模型 ,进一步分析模型有关特征值获得了草地有效管理期为返青后的第 73天到第 1 1 9天等十分重要的产量生态信息参数。生长季内地上生物量动态与前一个月的平均气温 ( R=0 .82 87)和积累降雨量 ( R=0 .8932 )均呈极显著正相关 ,这是实施科学水肥管理的重要参数 ;而地上部生物量最大绝对增长速率 ( AGR)出现在 6月 2 0日至 7月 5日 ,平均为 3.35 33g· m- 2 · d- 1干物质 ;而地上部生物量最大相对增长速率( RGR)出现在 5月 2 0日至 6月 5日 ,平均为 0 .0 6 6 2 g· g- 1· d- 1干物质 ;在生长后期绝对增长速率和相对增长速率均出现负值 ,这表明地上部生物量的生长效率在生长初期最高。地上生物量垂直空间格局由下向上呈幂函数变化 ,其模型为 :Bn=a Xb,其中 93%的产量集中在 4 0 cm以下 ,这对不同的家畜的选择利用与刈割利用提供了依据 ;不同种群对草原牧草产量形成的作用是不同的 ,羊草种群对草原牧草产量形成的正向     

土壤水分变化对长白山主要树种蒙古栎幼树生长的影响

选择长白山红松阔叶林主要优势树种蒙古栎为研究对象,人工控制3种施水量研究蒙古栎幼树形态、生物量效应和光合生理特征对土壤含水量变化的响应．结果表明,不同土壤含水量变化显著影响蒙古栎叶片、枝、根的生物量及其分配格局和叶片光合气体交换特征．水分胁迫改变幼树树冠结构,抑制幼树树高、地径、叶片大小、地上和地下生物量;同时,蒙古栎幼树根冠生物量比随着土壤水分含量的减少显著提高;供水量减少对幼树净光合速率、CO2利用率和碳利用率等特征有显著的负向影响;而叶片气孔导度、蒸腾速率和水分利用率对不同土壤含水量反应较复杂,只在土壤含水量较低时,幼树气孔导度、蒸腾速率明显降低,叶片水分利用率升高,表现出蒙古栎树种是干旱可变植物,长期水分胁迫可提高树种的耐旱能力．     

不同土壤水分条件下焕镛木幼苗的生理生态特性

在不同的土壤水分条件下 (土壤含水量分别为 2 0 1%、14 3%和 13 2 % ) ,比较研究濒危物种焕镛木幼苗的生理生态特性 ;测定了焕镛木叶片的净光合速率 (A)、气孔导度 (gs)、内在水分利用率效率 (WUE)、比叶面积 (SLA)及叶片的光合作用 光响应曲线。结果表明 :随着土壤含水量的增加叶片的净光合速率和气孔导度相应增高 ,生长在最高土壤含水量下的植株 ,日平均光合速率、气孔导度分别为 8 5 5± 4 32 μmol·m-2 ·s-1和 81 5 7± 8 4 1μmol·m-2 ·s-1,分别比生长在最低土壤含水量下的植株高 2 5 6 1%和 17 6 8% ;另一方面 ,水分利用效率、比叶面积随土壤含水量的降低而趋于增加 ,土壤含水量最低时 ,植株的日平均水分利用率、比别增加0 2 8%和 15 87% ,其中 ,水分利用效率的变幅较小 ;光饱和点随着土壤含水量的增加而增高。较高的土壤湿度有利于焕镛木的生长。     

盐生境下硅对坪用高羊茅生物学特性的影响

干旱半干旱区草坪绿地的长期灌溉容易引发土壤次生盐渍化,提高草坪草在盐生境下的生长发育能力是应对土壤次生盐渍化的主要途径之一.采用盆栽试验研究了盐生境下硅对坪用高羊茅(Festuca arundinaea)生物学特性的影响.结果表明,向盐生境土壤中添加不同浓度硅均提前高羊茅出苗时间2d,加快出苗速率,增加出苗总数,提高保苗率,且总出苗率和保苗率随着硅浓度增加而显著增大(P＜0.05),这说明盐生境下向土壤添加硅改善了幼苗完全死亡的现象.盐生境下硅显著增加了高羊茅叶长,株高和分蘖数,但对叶宽影响不显著,说明硅能够促进高羊茅生长,但对草坪绿地的质地影响不大.虽然硅能显著增加高羊茅总生物量(P＜0.05),但较低浓度时促进其茎叶生长,高浓度促进其根系生长.硅在高羊茅体内的沉积量随施入硅增加而增大,但其茎叶和根系内硅含量不超过3.0％,且根系内硅含量约为茎叶内硅含量的2倍.结果显示,硅提高了坪用高羊茅在盐生境下的适应能力,这为以后草坪绿地管理中应对土壤潜在盐渍化的问题提供了一定的科学依据.     

多效唑对紫穗槐生长及生理特性的影响

采用盆栽试验的方法研究了土施不同浓度多效唑(1、5、10、15、20 mg/L)对紫穗槐(Amorpha fruticosa Linn.)生长及生理特性的影响,以探明多效唑对紫穗槐的作用机制和最佳处理方式。结果显示:随着多效唑处理浓度(1~20 mg/L)的增加,紫穗槐幼苗株高、单叶面积和主根长呈下降趋势,基径、叶片长宽比、根鲜重和根冠比呈上升趋势;多效唑各处理均使紫穗槐幼苗叶片的相对含水量、叶绿素、可溶性糖和可溶性蛋白含量显著升高,POD活性显著增加,MDA含量和相对电导率显著下降。采用隶属函数法对各项生长、生理指标进行综合评价,结果发现20 mg/L多效唑处理下紫穗槐幼苗的抗性最强。说明多效唑可通过调节紫穗槐幼苗的生物量分配、水分状况、细胞渗透性和抗氧化性等,有效改善其生长、生理特性及提高抗逆性。本研究结果为多效唑在边坡植被建成和恢复中的应用提供了理论依据。     

干旱胁迫条件下AMF促进小马鞍羊蹄甲幼苗生长的机理研究

采用温室水分控制试验,在干旱胁迫条件下,定量化研究优势丛枝菌根真菌(AMF)影响优势乡土植物小马鞍羊蹄甲(Bauhinia faberi var.microphylla)幼苗生长的机理,主要通过研究干旱胁迫条件下摩西球囊霉菌(Funneliformis mosseae)与小马鞍羊蹄甲的共生关系,阐明AMF在植物生长初期的作用。结果表明,干旱胁迫条件下,摩西球囊霉菌能够很好地侵染幼苗,侵染率高达89%—97%,并且不受水分条件影响。接种的幼苗最大光合速率、水分利用效率随着干旱胁迫程度从重度到轻度(水分从低到高)逐渐增大,相反地,叶片脯氨酸含量逐渐减小。接种显著地促进幼苗株高、叶片数、叶面积、根长、根面积等生长指标,提高幼苗各部分生物量、地上地下磷(P)含量。当含水量为60%田间持水量时,AMF促进小马鞍羊蹄甲幼苗吸收P的效果最好。接种还显著影响幼苗的生物量分配,在重度干旱胁迫时影响P分配,水分条件也显著影响幼苗的生物量分配。此外,接种和水分的交互作用对叶生物量、总生物量、生长指标以及地上部氮(N)总量影响显著。结果表明干旱胁迫条件下菌根效应显著,并在干旱条件下显著促进了小马鞍羊蹄甲幼苗的生长,这为进一步干旱河谷植被恢复提供了理论依据。     

补充UV-B辐射对浙贝母生长和光合作用的影响

通过模拟西安地区自然光中U V2B辐射,增大辐射剂量对浙贝母生长和光合作用的影响进行研究.3个增强的U V2B辐射2.54、4.25及5.31k J·m-2处理导致浙贝母株高、叶面积、单株干重、叶绿素含量降低,而茎粗增加.在3个U V2B处理中,生物效应以5.31k J·m-2处理为最大,2.54k J·m-2处理影响最小.同时增加的U V2B还使浙贝母的光合速率、蒸腾速率、水分利用率下降,作用效果与辐射强度呈正相关.分析认为,浙贝母对U V2B辐射具有一定的敏感性.     

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。