低温条件下外源物质对棉株不同部位果枝棉铃纤维比强度的影响

在棉纤维加厚发育期20.0℃的日均温条件下,对棉花6~9果枝(中部果枝)和11~14果枝(上部果枝)1、2果节棉铃及其对位果枝叶分别于花后15 d和30 d,外施C/N比恒定的3种外源物质:(1)6%蔗糖和0.6%谷氨酰胺混合溶液(C+N),(2)6%蔗糖、0.6%谷氨酰胺和2μg.g-16-BA混合溶液(C+N+BA),(3)2μg.g-16-BA溶液(BA),研究低温条件下外源物质对棉株不同部位果枝棉铃纤维比强度的影响。结果表明:花后15 d外施C+N+BA可提高棉花上部果枝铃铃重和衣分,花后15 d3、0 d外施C+N+BA均可提高棉花中部果枝铃铃重和衣分。花后15 d3、0 d外施BA均有利于棉花上部果枝铃衣分的提高。花后15 d、30 d外施C+N、C+N+BA、BA均导致棉花上部果枝铃棉纤维的螺旋角和取向分布角变大,纤维比强度降低,但可优化中部果枝铃棉纤维的螺旋角和取向分布角,提高纤维比强度,且以BA处理效果最佳。     

棉花纤维发育关键酶对氮素的响应及其与纤维比强度形成的关系

大田栽培条件下,于2005～2006年在江苏南京（118°50′E,32°02′N,长江流域下游棉区）以美棉33B（平均比强度32cN／tex）和科棉1号（平均比强度35cN／tex）2个品种为材料,进行氮素水平（O（零氮）,240（适氮）和480kgN／hm^2（高氮））实验,研究棉花纤维发育关键酶（蔗糖合成酶和β-1,3-葡聚糖酶）活性变化特征对氮素的响应及其与纤维比强度形成的关系．结果表明,棉纤维发育关键酶活性及其基因表达强度均受氮素影响,并影响棉纤维素的累积特征及纤维比强度的形成．蔗糖合成酶活性随铃龄增加呈单峰曲线,峰值出现在铃龄31天,其基因表达强度在7～21天维持较高水平;氮素水平间比较,以240kgN／hm^2处理的蔗糖合成酶活性及其基因表达强度最高,酶活性高表达持续时间长．β-1,3-葡聚糖酶活性随铃龄增加呈下降趋势,其基因表达在铃龄7～24天间呈单峰曲线,铃龄18天时达到峰值;氮素水平间比较,以240kgN／hm^2处理的β-1,3-葡聚糖酶活性最高,其基因表达量在纤维发育前期（铃龄9～12天）较低,之后大幅增加且稳定表达．240kgN／hm^2下棉纤维发育关键酶的上述变化促进纤维素累积持续期长且整个纤维发育过程中纤维素累积速率平缓,最终形成纤维比强度较高。     

应用改良滴冻法超低温保存两种柿属植物的研究

以君迁子（Diospyros lotus L．）和柿（D．kaki Thunb．）组培苗茎尖为试材,对影响超低温保存效果的主要因素,如低温锻炼方式、预培养条件、PVS：（30％甘油＋15％乙二醇＋15％二甲基亚砜＋0．4mol／L蔗糖）处理时间等进行了研究。建立了2种柿属植物的超低温保存程序：（1）切取1cm左右试管苗梢段继代到1／2MS（KNO3和NH4NO3减半）培养基中,交替低温[昼（25±1）℃、夜（4±1）℃]锻炼6周;在含0．5mol／L蔗糖的1／2MS培养基上预培养5d,20℃下装载液（2．0mol／L甘油＋0．4mol／L蔗糖）过渡10min,0℃下PVS2处理1．5h;（2）投入液氮保存;（3）40℃水浴化冻,洗涤5～6次后接种于含1．0mg／LTDZ、0．6g／L可溶性PVP、30g／L蔗糖和7．0g／L琼脂的培养基（作者在优化柿属植物离体培养体系试验中获得）上暗培养1周,转入25℃,1500lx培养室。按照上述程序培养,‘鄂柿1号’、‘湘西甜柿’和君迁子的成活率分别为79．6％、67．4％和60．9％。     

低温对棉纤维比强度形成的生理机制影响

通过设置播期试验使棉纤维加厚发育过程(铃龄25~50 d)处于不同的温度条件下,研究低温对棉花纤维比强度形成的内在生理机制影响,为采取调控措施解决目前棉花(Gossypium)生产中存在的晚熟劣质问题提供理论依据。两年试验结果表明:棉纤维加厚发育期24.0 ℃左右的日均温是高强纤维形成的最佳温度,其内在生理机制表现为棉纤维蔗糖合成酶活性最高,β_1,3_葡聚糖酶活性最低,纤维素的累积量和累积速率均明显高于其它低温条件,纤维超分子结构取向参数角较小,处于优化状态,最终表现为纤维比强度亦最大;低于21.0 ℃时即对棉纤维加厚发育相关酶活性产生明显影响,纤维比强度降低。当温度降到15.0 ℃左右时,棉纤维蔗糖合成酶活性显著降低,而β-1,3_葡聚糖酶活性显著升高,同时纤维素累积量和累积速率均显著降低,纤维超分子结构取向参数角明显宽化,棉纤维不能正常发育,不利于高强纤维的形成(铃重仅为3.22 g,纤维比强度仅为15.73 cN·tex^-1)。     

氮素营养对非洲菊组织培养芽增值的影响

非洲菊（Gerberajamesonii）品种“签证”的无菌芽，以MS培养基（内含3％蔗糖、0．8％琼脂、10．0mg·L－1KT、05mg·L－1IAA，pH5．8）培养。每100ml的三角瓶内装30ml培养基，接6个芽，置于2000lx光照度（10h·d-1），白天20～30℃、夜间10～15℃下培养。以MS中全氮量为1（MSN），另设1／2含氮量（1／2N）和1／4含氮量（1／4N）处理。铵态氮（NH＋4４－N）和硝态氮（NO－3－N）比值试验是在总氮浓度不变的条件下调整两者浓度，共设2：1、1：1、1：2和1：5四个处理。所有上述处理均接10瓶，培养5周后随机取5个丛芽进行测定。结果…     

冬桃的离体繁殖

1植物名称桃（Prunuspersica）品种“冬桃”。2材料类别3年生嫁接苗树冠外缘向阳果枝的嫩梢腋芽。3培养条件基本培养基为MS。（1）芽诱导和增殖培养基：MS＋6－BA0．8～2mg／L（单位下同）＋IBA0．4～0。8＋GA3～5;（2）生根培养基：MS＋IBA0．4～07＋NAAof～03o培养基中含蔗糖3％（W／V）、琼脂0．8％,PH为5．8,培养温度25土豆C,光照度1200IX,照光12h／d。毛生长与分化情况外植体在无菌条件下用0．2％升汞95ml＋95％酒精5ml浸泡8min（使灭菌液更易附着于表面组织）,无菌水冲洗4～5次,然后切成l～2cm长带腋芽的茎段,接…     

毛果杨的组织培养与快速繁殖

1植物名称 毛果杨（Populus trichocarpa Torr．＆Gray）,又称测序杨。 2材料类别 茎段。 3培养条件（1）基本培养基：1／2WPM＋3％蔗糖;（2）增殖培养基：WPM＋TDZ0．5mg·L^-1（单位下同）＋IBA0．05＋3％蔗糖;（3）生根培养基：1／2WPM＋IBA0．15＋2％蔗糖。培养基加入5．5g·L^-1琼脂,培养温度为18-25℃,     

墨兰的组织培养和快速繁殖

1植物名称墨兰品种企黑（Cymbidiumsinensecv．Qihei）和白墨（C。sinensecv．Baimo）。2材料类别墨兰种子于培养基中萌发后产生的原球茎。3培养条件（1）种子萌发培养基：1／2MS十适量琼脂;（2）芽分化培养基：1／2MS＋6－BA5．0mg·L－1（单位下同）＋NAA0．5十椰汁50ml·L－1;（3）转瓶培养基：1／2MS＋6－BA2．0＋NAA1.0＋5％活性炭。培养基中加3％蔗糖,0．8％琼脂,PH5．5。培养温度25±2℃,光照强度2W·m－2,每天光照10h。4生长与分化情况4．1种子萌发形成原球茎墨兰葫果以70％酒精消毒15min,在无菌条件下取出种子置…     

假槟榔种子脱水耐性的发育变化

对假槟榔（Archontophoenix alexandrae）种子和胚发育过程中脱水耐性的变化、不同脱水速率对脱水耐性的影响及种子的萌发和贮藏特性进行了研究。种子含水量在花后55～70d逐步降低,随后不再变化,并保持在较高水平（37％）;花后90d的种子获得最大干重。花后60d后种子获得萌发能力,花后70d达到最大值。在交替光照下（14h光照,10h黑暗,12μnmol m^-2s^-1）,种子在15℃～40℃下均能萌发,其萌发的适宜温度范围为30℃～35℃;但光照对种子的萌发有较大的抑制作用。种子和胚在花后55～90d,脱水耐性逐渐增强;花后90d种子和胚的脱水耐性最强,此时种子和胚的半致死含水量分别为0．18g／g和0．3g／g。脱水至相同含水量,快速脱水的种子的存活率明显高于慢速脱水。无论是否进行脱水处理,-18℃下贮藏1个月后,种子均丧失萌发能力;在4℃,10℃和15℃下,适度脱水能延长种子的贮藏寿命。假槟榔种子不耐脱水,不适合在低温、低含水量条件下长期贮藏,属顽拗性种子。     

西藏绵头雪莲的组织培养及植株再生

1植物名称绵头雪莲（Saussurealaniceps）。2材料类别种子子叶。3培养条件培养基：（1）N6＋BA2mg·L－1（单位下同）＋NAA0．02;（2）N6＋BA1.5＋NAA0．2 水解乳蛋白500;（3）N6＋NAA0.5＋IAA0．5＋KCI60。培养温度：25~28℃,光照度2400lx,光照12－14h·d－1。4生长与分化情况4．1愈伤组织诱导及芽的分化经表面消毒后的种子接种子培养基（1）上,7－10d后种子前发长出了叶,10－15d后,子叶边线突起。膨大,产生紫绿色的愈伤组织。20－25d后,愈伤组织上突起产生绿色芽点,经10－20d,不定芽伸长至0．5－1．5cm。1块愈伤组织…     

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。