水稻幼穗培养高效再生系统的建立

本文测试了不同基因型幼穗取材时期、消毒方式、4℃下处理时间、愈伤组织诱导、分化及生根条件等对水稻幼穗培养再生成株的影响,实验结果表明,在优化条件下,籼稻的绿苗分化率在85%以上,成苗率115%左右;粳稻的绿苗分化率在90%以上,成苗率130%左右;粳型广亲和的绿苗分化率、成苗率分别达到85%和115%以上。由此建立了一套高效、可靠、重复性好的水稻组织培养再生系统,为水稻遗传转化的顺利进行奠定了基础。     

水稻幼穗组培及白化苗的电镜观察

木文报道了五份水稻材料的幼穗组培的诱导率和分化率,对继代８次后的幼穗愈伤分化出的白苗和绿苗及其各自的愈伤进行电镜扫描,发现白苗的质体结构不完整,不能正常合成叶绿素。     

野生稻不同外植体的离体培养

野生稻不同外植体离体培养时的幼穗愈伤组织诱导率差异在８．７％￣９４．７％之间,成熟种胚愈伤组织诱导率普遍高于幼穗,但很少能再生绿苗。野生稻幼穗直接分化培养再生绿苗率普遍高于通过愈伤组织培养分化的再生绿苗率。     

不同类型水稻的组织培养和细胞悬浮培养

我们(1980)曾报道过晚粳稻台中育39和杂交水稻汕优6号幼穗、茎、叶鞘等外植体愈伤组织的诱导率、分化率及其试管苗得率的情况及其在温室、大田的性状表现(赵成章等1980),并指出水稻幼穗外植体具有很强的分化能力。因此,本实验以水稻的幼穗为材料,比较研究不同类型水稻品种幼     

提高春小麦花粉植株诱导率的研究

本文研究了影响春小麦花粉植株诱导率的几种主要因素。供试材料为1990年温室种植的杂种F_1代,试验结果表明,诱导培养基中附加细胞分裂素BA或BA与KT相结合能显著提高愈伤组织分化率;0.17M的葡萄糖加0.17M的蔗糖比用0.26M的蔗糖愈伤组织诱导率高60％以上;愈伤组织在18～25℃比在23～25℃下培养绿苗率显著提高;接种前2～3℃预处理幼穗72小时对提高出愈率和绿苗分化率有明显效果。     

不同组织培养途径对小麦再生能力的研究

从现在推广的小麦优良品种和有苗头的新品系中选用10个小麦基因型品种进行组织培养,从愈伤组织诱导率、绿苗分化率等方面比较了幼穗培养、花药培养、幼胚培养三种培养方式的培养效果。结果表明,幼胚培养效果最好,基因型间差异小,都能获得足够数量的再生植株。幼穗的培养效果最差,愈伤组织分化生根和绿芽十分容易,但分化成完整植株则较为困难。花药培养在基因型间差异非常明显而且有较多白化苗。此外,本研究还分析了影响小麦再生能力的因素,建立了一套高效、可靠的小麦组培再生系统,为小麦的转基因技术提供优良的受体材料。     

Cu2+对小麦花药脱分化和再分化特性的影响

以3个普通小麦杂交组合的F1群体为材料,研究了小麦花药离体培养中Cu2 对花药组织脱分化和再分化特性的影响.结果表明,诱导培养基中的Cu2 对小麦花药愈伤组织的诱导及再分化均有影响,均表现为低浓度下的促进作用和高浓度下的抑制作用,最适Cu2 浓度为0.15μmol/L.在该浓度下,3个供试材料的出愈率分别比对照提高了239.14%、214.72%和80.00%,反应率分别比对照提高了156.70%、151.86%和65.96%,绿苗分化率分别比对照提高了200.05%、241.87%和333.49%.再分化培养基中的Cu2 对小麦花药愈伤组织的再分化有明显的负向效应,3个供试材料中,均以不附加Cu2 的对照的绿苗分化率最高,分别为70.00%、66.67%和39.29%,附加不同浓度的Cu2 后,绿苗分化率显著下降.     

釉稻胚培养力与农艺性状的相关分析

木文研究了32个釉稻品种〔品系）的成熟胚愈伤组织诱导率和绿苗分化率与植株农艺性状的相关 系数,并进行逐步回归分析。结果表明,在釉稻成熟种胚离体培养中,绿苗分化率除与愈伤组织诱导率 有极显著正相关（r二0.758**）外,与生育期、粒长、千粒重、穗长等农艺性状也有显著或极显著相关, 但逐步回归分析表明,绿苗分化率仅与粒长有关,决定系数仅。.21夕。     

不同时期土壤营养与空气营养对水稻器官生长发育的影响

1.本試驗采用大田竹筒栽培固定土壤因素,改变空間距离的方法,探討水稻在幼穗分化始期前后空气营养对水稻器官生育的影响。采用固定空間距离来控制空气因素,而以大田栽培和竹筒栽培来改变土壤因素的方法,探討水稻在幼穗分化始期前后土壤营养对水稻器官生育的影响。 2.試驗結果初步說明,水稻在幼穗分化始期以前加强土壤营养,而后加强空气营养,对水稻器官的生长发育具有良好的效果。 3.幼穗分化始期加强通风透光处理試驗結果証明:在水稻幼穗分化始期进行放寬行距、缩小株距、稀疏等来加强通风透光处理,以增加生育后期的空气营养,能显著地提高水稻的抗倒伏性,促使稻穗发育良好。 4.从試驗中初步得到的結果,我們认为:水稻群体与外界环境条件的統一过程中,存在着两个基本的矛盾——空气营养和土壤营养,其轉折点可能在幼穗分化始期,在此以前土壤营养是主要的,而后空气营养是主要的,合理調节这两个矛盾(卽空气营养和土壤营养)是密植增产的重要关鍵。     

玻璃温室与田间栽培小麦幼穗分化的比较

以河南省大面积种植的弱春性品种"郑麦9023"及半冬性品种"周麦18"为材料,开展了玻璃温室和田间栽培条件下小麦幼穗分化进程的比较研究。结果表明,在小麦全生育期,玻璃温室内平均温度高于田间环境,小麦幼穗分化所需时间极显著低于田间环境(P < 0.01)。温度和0 ℃以上积温升高,小麦幼穗分化进程加快。与田间种植小麦相比,玻璃温室内小麦幼穗分化缩短的时期主要集中在分化前期(出苗-伸长期、单棱期、二棱期)。玻璃温室内小麦幼穗分化持续时间和总积温均随播期推迟而降低,幼穗分化各阶段出现时间亦随播期的推迟而后延。小麦幼穗分化进程存在品种间差异,其中"郑麦9023"幼穗分化持续时间小于"周麦18",各阶段出现的时间亦早于"周麦18"。温度对幼穗分化各时期的影响存在品种间差异。温度升高对"郑麦9023"幼穗分化中期(二棱期、护颖分化期、小花分化期)影响较大,对"周麦18"幼穗分化前期和后期(单棱期、二棱期、药隔分化期)影响较大。积温对"郑麦9023"护颖分化期和"周麦18"药隔分化期、二棱期影响较大。     

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。