多效唑对金钗石斛试管苗生长的影响

多效唑是一种高效的植物生长延缓剂,通过不同浓度的多效唑对金钗石斛试管苗生长的影响进行研究。结果表明多效唑能明显提高金钗石斛试管苗再生芽分化的数量,促进再生苗根的分化,提高生根的数量;同时,多效唑能使再生苗的叶片变短,对再生植株有显著的矮化作用,使植株的茎段变粗,抑制根的伸长生长。多效唑对金钗石斛试管苗生长的影响具有明显的规律性,其作用效果均随着其使用浓度的升高而增强,并在3~4mg/L的范围处达到最强效果,再提高浓度则趋于饱和。     

水稻试管苗保存技术（简报）

多效唑与6-BA及NAA配合使用明显抑制水稻试管苗地上部生长,促进根系发育,对再生苗的发育影响较小,其有效作用期90天左右。水稻试管苗在含多效唑的N_6培养基上可保存4～6个月,对长期保存试管苗多效唑适宜浓度为5～10mg/L,移植前3～4周应补加一次营养液以利壮苗。     

多效唑（MET）对啤酒花试管苗生长和移栽的影响

在培养基中加入0.1-0.2mg/L浓度的多效唑（MET）,啤酒花试管苗植株矮壮,单株生根数量增加、移栽成活率提高13％。0．5－2．0mg/L时,试管苗基部愈伤组织增多,枝叶失绿,生长受到抑制。初步发现多将唑对啤酒花试管苗的效力与葡萄糖用量呈正相关。     

草莓的组织培养与快速繁殖研究

通过对草莓的茎尖生长点进行组织培养,获得草莓脱毒苗,并以此为试材,对草莓的快速繁殖以及生根培养进行了研究。结果表明：芽的最适诱导分化培养基为MS BA0．5mg／L IAA0．05mg/L,诱导率可达70％;最适增殖培养基为MS BA0．2～1．0mg／L,增殖倍率可达3．2;试管苗在1／2MS附加IAA0．5me／L的培养基上,经过10～15d的培养,95％生根成苗。     

枇杷种质资源的离体保存研究Ⅱ生长抑制剂的影响

在枇杷种质资源离体保存中,加入植物生长抑制剂可以延缓枇杷试管苗的生长速度,延长保存时间。实验结果表明,有利于枇杷种质保存的3种生长抑制剂浓度分别是:多效唑(PP₃₃₃)2~5mg/L、矮壮素(CCC)25mg/L、脱落酸(ABA)10mg/L;其中浓度为5mg/L的多效唑效果最为理想。高浓度的甘露醇(>5g/L)对试管苗会造成毒害,不利于枇杷种质的保存;5g/L甘露醇保存效果较好     

硝酸镧对霍霍巴多芽苗生长的促进作用及植株再生

在增殖培养基(改良MS 2mg／L6-BA 0．5mg／LG3)中添加1～3．5mg／L硝酸镧,对霍霍巴试管苗生长有显著促进作用,2．5mg／L硝酸镧对多芽分化有极显著的促进;在生根培养基(改良1/2MS 3mg／LIBA 1．5mg／LNAA)中,1～2mg／L的La(NO3)3对根的分化有显著的促进作用,生根率提高,最佳浓度为2．0mg／L。过高的浓度对试管苗生长有一定抑制。试验表明,不同器官对硝酸镧的敏感程度不同。取2cm高以上的霍霍巴试管苗,用25mg／L IBA或NAA处理30min,扦插于沙基质中。保持室温20～30℃。50d后揭去覆膜,保持光强3000 lx,相对湿度85％以上。正常管理条件下成活率达75％。     

植物生长延缓剂MET在水稻组织和细胞培养中的作用

目前植物试管苗生长尚不正常,普遍存在着再生苗生长细弱,移栽成活率低,抗逆性差,在试管中不能长期保存等问题,严重影响试管苗的培养效率和进一步开发应用。目前高效植物生长延缓剂多效唑(MET)的应用,为植物再生苗生长发育调控提供了可能条件,本文就 MET 在水稻组织和细胞培养中的作用和影响进行系统研究,取得很明显的培养效果。方法是将再生绿芽或未成熟胚接种在含 MET2.5mg/L 6-BA 2mg/L NAA0.2-0.     

稀土元素对霍山石斛试管苗生长的影响

目的：研究稀土元素镧（La）、钐（Sm）、铱（Ye）对霍山石斛试管苗生长的影响。方法：运用植物组织培养技术在基本培养基中添加不同种类、不同浓度的稀土元素,60d后统计其对霍山石斛试管苗各项生长指标。结果：1／2MS＋10％香蕉培养基中添加l0mg／L Sm、l0mg／L Ye对其试管苗有矮化作用和促使密集的分蘖和生根;添加l0mg／L La促进植株增高、鲜重增加、叶绿素含量提高、芽分化加快、根数目增多、;而添加l00mg/L La对其试管苗生长起明显抑制作用。结论：稀土元素对霍山石斛试管苗的生长有显著的影响。     

草莓试管苗分化培养基优化的研究

本研究采用三种培养基（A3、F、MS）进行草莓分化对比试验．结果表明我们研制的A3基对草莓试管苗分化有明显促进作用．连续培养11周,A3的草莓苗总分化率是F基的1．25倍,是MS基的1．51倍。而且,A3基成本低于其它两基。A3、F和MS无机盐含量分虽为：1782．58mg／L、2868．33mg／L和4633．33mg／L。无机盐种类的合理配比及其低浓度有利于草莓试管的分化培养。     

多效唑在植物组织培养中的应用

多效唑是英国ICI有限公司,在２０世纪８０年代末,推出的一种高效低毒的植物生长延缓剂。它通过阻碍贝壳杉烯向异贝壳杉烯酸的氧化,抑制生物体内赤霉素的生物合成,从而抑制植物的生长。目前在果树、蔬菜、花卉及大田粮食作物上已得到广泛应用。近年来,多效唑又开始在植物组织培养中应用,并取得了一定的效果。以下是多效唑在各种农作物和花卉组培中的应用效果简介,以供广大读者参考。一、在主要粮食作物上的应用：１．当多效唑加入到小麦花粉愈伤诱导及分化培养基中,对其出愈率及绿苗的分化率均影响不明显。而３mg／L的多效唑,对小…     

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.     

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.     

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.