杜仲叶林枝木醋液化学成分及抑菌活性研究

以杜仲叶林枝木为原料,采用干馏法,分90℃~200℃、200℃~340℃和340℃~520℃共3个温度段收集杜仲叶林枝木粗木醋液,经过静置、活性炭粉吸附焦油处理等过程得到精制木醋液,然后对所得木醋液的理化性质和抑菌活性进行了研究,并对抑菌活性最强的木醋液的化学成分进行了GC/MS分析。结果表明:(1)杜仲叶林枝木醋液产生的温度范围为90℃~520℃,其中200℃~340℃段产量最大、pH值最低、有机酸含量最高、抑菌能力也最强。(2)GC/MS分析表明,温度段为200℃~340℃的木醋液中约含有42种化合物,主要为酚类、酸类、酮类和醛类等,其中酚类化合物含量最高,占总量的46.81%,其次为有机酸类物质。初步分析确定木醋液抑菌活性成分为酚类物质。     

不同温度及盐碱环境下盐地碱蓬的萌发策略

为了研究黄河三角洲优势种盐地碱蓬在不同胁迫环境条件下的萌发策略,分别在不同温度、盐度、碱度以及海水原溶液条件下,进行了室内萌发实验,并且测量了其幼苗体内的Na+和K+含量.结果表明,盐地碱蓬种子发芽所需要的积温和最低温度分别为24.57℃·d和0.62℃,最适发芽温度为20℃～35℃,在温度5℃～40℃下均表现出较高的发芽率而且5℃～35℃下发芽速度随温度升高而显著增加.盐地碱蓬具有较高的耐盐性,当盐浓度达到500 mmol·L-1时,发芽率均高于50%,并且在100%海水溶液浓度下发芽率也能达到38%,高盐条件下未萌发的种子转移到淡水中,均表现出较高的复萌率.盐地碱蓬幼苗体内Na+含量随盐度(NaCl溶液浓度)升高而显著增加,而K+含量在该盐度下差异不显著;幼苗体内Na+、K+含量在高碱度(200和300 mmol·L-1 NaHCO3)中均显著低于其在低碱度(100mmol·L-1NaHCO3溶液)中的含量,说明碱胁迫对幼苗生长产生了显著性影响;Na+、K+含量均随着海水溶液浓度增加而显著增加.因此,盐地碱蓬种子萌发的广温性、高耐盐性、高盐环境中的种子高存活率以及幼苗的较强的耐盐能力是盐地碱蓬种群在黄河三角洲适应滨海盐碱湿地复杂环境的主要生存策略.     

基于实验与文献研究热解温度和原料对木醋液组分的影响

为探讨不同原料、温度对木醋液组分的影响及其相互关系,分析了不同温度段的桉树木醋液组分,利用木醋液、木醋酸、Wood vinegar、Pyroligenous acid、Smoke liquid和Prolysis liquid等关键词,检索和查阅了国内外主流数据库10个,文献发表时间从1996年至2020年,经甄别筛选关于木醋液组分与含量研究有效文献75篇,包括低温和高温段的桉树木醋液组分数据。采用聚类热图分析、NMDS分析、线性回归分析、相关性分析和随机森林模型等统计学方法对木醋液组分进行分析,结果表明:热解温度低于和高于350℃的木醋液组分存在明显差异(P0.01,R=0.466)。在热解温度低于350℃时,酸类物质平均相对含量最高(39.66%),当温度高于350℃时,酚类物质相对含量较低温段增加了1.9倍,酸类物质和醛类物质含量分别减少了86%和56%。温度与酸类物质(y=-0.08x+55.7)和酚类物质(y=0.03x+19.15)分别呈显著负相关和正相关线性关系。随机森林模型分析结果表明:木醋液组分中酸类物质(MDA=14.9%,MDGini=25.4%)和酚类物质(MDA=9.7%,MDGini=19.25%)是木醋液组分的主要物质。酚类物质和酸类物质呈显著负相关(P0.01,r~2=-0.43),醇类物质和酮类物质呈极显著正相关(P0.01,r~2=0.23),其中,乙酸(29.48%)是酸类物质中含量最高的化合物,其次为丙酸(3.13%),酚类物质以苯酚(8.07%)、2-甲氧基苯酚(8.02%)和2,6-二甲氧基苯酚(5.72%)等化合物为主。糠醛(8.31%)、1-羟基-2-丙酮(5.18%)和糠醇(2.52%)分别是醛类物质、酮类和醇类物质的主要化合物。本研究为木醋液功能性产品的开发以及生物质固废资源化利用提供参考与借鉴。     

温度及盐胁迫对地梢瓜种子萌发及抗氧化酶活性的影响

以地梢瓜种子为试料,研究不同温度(5~45℃)及不同浓度NaCl胁迫(0~300mmol·L~(-1))对种子萌发及其抗氧化酶活性的影响。结果表明:(1)随着温度升高,种子各萌发指标呈先升高后降低的趋势,过高或过低均显著抑制种子正常萌发,萌发最适温度为25℃,在5℃和35℃条件下种子恢复萌发率均达95%以上。(2)随着NaCl浓度升高,种子萌发率、萌发势、活力指数呈显著下降趋势,而其相对盐害率呈增加趋势,且在300mmol·L~(-1)NaCl时萌发受到完全抑制;种子根系活力仅在高浓度NaCl(150mmol·L~(-1))下受到显著抑制;种子在解除盐胁迫后可一定程度恢复萌发,但最终依然受到盐胁迫的显著抑制,且盐浓度越高抑制越严重,其耐盐适宜浓度为65.25mmol·L~(-1)。(3)种子萌发率与盐胁迫下POD、APX活性呈显著正相关关系,而与相应O_2~生成速率、MDA含量呈显著负相关关系;种子活力指数与盐胁迫下CAT活性呈显著负相关关系。研究发现,地梢瓜种子萌发受到NaCl胁迫的显著抑制,保护酶POD与APX在盐胁迫种子萌发过程中发挥着主要抗氧化作用;地梢瓜适于在中度盐渍土中萌发生长。     

药用植物种子生物学特性的多样性(摘要)

本文对药用植物种子形态结构多样性、休眠习性的多样性、萌发习性的多样性进行了研究。1　药用植物种子形态和结构的多样性(1 )种子外部形态的多样性 ;(2 )种子内部结构的多样性 :①种皮结构的多样性 ;②胚的结构多样性 ;③胚乳的多样性。2　药用植物种子休眠习性的多样性(1 )种皮休眠 ;(2 )胚休眠 :①胚未完全分化引起的休眠 ;②生理休眠。3　药用植物种子萌发习性的多样性(1 )低温型种子 ,萌发最适温度 1 5℃左右。(2 )中温型种子 ,萌发最适温度 2 0～ 2 5℃。(3 )高温型种子 ,萌发最适温度 3 0℃。(4)变温型种子 ,萌发要求有昼夜一定变化…     

少花龙葵种子萌发特性及其果汁对小白菜种子萌发的影响

对少花龙葵的成熟果实采用3种采种方式,于室内测定水分、温度、光照条件对不同采种方式所得种子的发芽影响,并就少花龙葵的果汁对小白菜种子萌发的影响进行分析.结果表明:(1)少花龙葵种子于25℃恒温下浸种8 h后吸水达到饱和,其适宜发芽温度为20℃～25℃,萌发受黑暗抑制;(2)3种采种方式中以捣烂果实后种子不从果实取出并不清洗而直接晾干的采留种方式最佳;(3)少花龙葵果汁原液和其5～10倍稀释液抑制广东小白菜种子发芽,20～50倍稀释液则促进其萌发,表明少花龙葵果汁具有化感效应.     

狼毒种子萌发特性与种群更新机制的研究

研究了采集于植株上的和收集于土壤种子库的狼毒(Stellera chamaejasme)种子在不同温度、光照和5种预处理(即破裂种皮、去除种皮、98％H2SO4浸种5min、0．2％KNO3浸种24h、10℃低温保存1周)条件下的萌发力。结果表明,狼毒种子萌发率较低,25℃恒温、黑暗条件下萌发率为13％,较适宜的萌发温度为30℃恒温或10～30℃变温,破裂种皮和去除种皮萌发率显著提高,25℃恒温、光暗交替条件下萌发率分别为49％和47％,浓硫酸浸种5min处理萌发率可达到32％,KON3浸种和10℃低温保存两个处理对促进狼毒种子萌发效果不明显,狼毒种子萌发对光照条件不敏感,种子硬实性是导致狼毒种子萌发率较低的主要原因,取自土壤种子库内的狼毒种子萌发率高于当年采集的种子,在自然条件下,并非每年都有狼毒种子萌发长成幼苗,种群更新时机是随机的或周期性的。     

贵州石笔木种子内源有机化合物及对种子萌发的影响

该研究采用浸提法和GC-MS检测了贵州石笔木种子内源有机化合物种类、相对含量,以及种皮和胚乳在不同溶剂、温度和浓度条件下的浸提物活性。结果表明:(1)种皮和胚乳中皆含有有机酸、烯、酯、醇、醛、酚6类相对含量较高的有机化合物,其中种皮含有机酸7种、烯类1种、酯类5种、醇类3种、醛类3种、酚类1种,胚乳含有机酸6种、烯类1种、酯类1种、醇类1种、醛类1种、酚类1种。(2)种皮浸提物活性显著高于胚乳浸提物活性(P0.05),且其烯、醛、醇和酯类含量分别高出胚乳含量的8.78%、2.66%、2.15%和1.70%,可能是对种子萌发起主要作用的内源抑制物质。(3)不同条件下处理的浸提液均能显著抑制白菜种子发芽及幼苗生长,浸提液抑制物活性表现为醇溶剂大于水溶剂,并随着浸提液浓度的升高而增大、随着浸提温度的升高而增强,在初始温度为100℃时,浸提液抑制活性达到最大值。贵州石笔木种子的内源有机化合物在种子萌发过程中发挥着不同程度的抑制作用,探索其与种子萌发的作用机制,解决种子萌发育苗的关键技术及在农林业生产中应用,这在植物种子的生物学特性及萌发生理研究方面具有重要意义。     

两种独行菜种子萌发生理特性研究

以两种在新疆具有代表性的十字花科独行菜属早春短命植物抱茎独行菜（Lepidium perfoliatum Linnaeus）和独行菜（Lepi-dium apetalum Willd）为材料,研究（光照、温度、外源激素ABA处理）对其种子萌发的影响。结果：两种独行菜种子萌发对光照不敏感;抱茎独行菜种子萌发的温度范围广,在0℃～25℃之间都可萌发,而独行菜种子则在低温下（0℃、4℃）不萌发,其萌发温度范围为10℃～25℃。两种独行菜种子对低温胁迫表现出不同的耐受性;0℃、4℃下,在培养基中加入不同浓度的ABA,对抱茎独行菜种子萌发有抑制作用。     

外来物种互花米草种子萌发的生态适应性

在3种条件即不同萌发温度和光照、不同贮藏温度和时间、不同盐浓度下,研究了互花米草种子萌发及胚生长特性.结果表明:在相同温度下,种子的萌发不受光照或黑暗条件影响,最适萌发温度为16/26℃(夜/昼)和25℃,萌发率高于90%;在-5℃、0℃、5℃、10℃的贮藏温度下,贮藏120 d的种子萌发率高于74%,表明种子能够安全越冬;当盐浓度为75～225 mmol·L~(-1)时,萌发率高于90%,150 mmol·L~(-1)的盐浓度较适宜胚的生长,胚芽鞘和胚轴的生长先于胚芽和胚根,盐溶液对胚轴、胚芽鞘的生长所产生的抑制作用小于胚根、胚芽,有利于已萌发的幼苗快速出土,适应多变的潮间带环境.     

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.     

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.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

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.     

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。     

Time of detection of recessive genes: effects of system of mating and number of examined individuals

Summary Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, Siete Cerros 66 and Penjamo 62, as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of Penjamo 62 in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed.