大气污染对38种木本植物的伤害特征

38种苗龄1—2a生的木本植物盆栽于相对清洁区(华南植物园和2个污染点：佛山市南海区五星和佛山市禅城区东村。1a后,根据叶片伤害程度、新叶增长率、种个体长势、翌春植株恢复状况等综合评价植物对氟化物、硫化物和酸雨组成的大气复合污染的敏感性反应。根据试验结果将供试植物对大气污染的敏感性反应分为3种类型：(1)低敏感性(抗性强),有茶花、红花油茶、傅园榕、小叶榕、桂花、环榕、菩提榕、石笔木、毛黄肉楠、幌伞枫10种。(2)中等敏感(抗性中等),有仪花、格木、吊瓜树、腊肠树、海南红豆、猫尾木、红桂木、灰莉、铁冬青、密花树、白桂木、小叶胭脂、大头茶、复羽叶栾、灰木莲、火焰木、华润楠17种。(3)高度敏感(抗性弱),有铁刀木、观光木、白木香、日本杜英、蓝花楹、蝴蝶树、印度紫檀、柳叶楠、无忧树、海南木莲、乐昌含笑11种。研究结果可为热带、南亚热带地区有类似大气污染的环境进行园林绿化,生态公益林营造提供参考。     

39种木本植物对大气污染的生理生态反应与敏感性

39种1-2a生盆栽木本植物在生长季前期放置在污染区（佛山南海区小塘镇五星)和清洁区(广州华南植物园),5个月后进行植物叶片和叶绿素荧光特征参数的测定。大气监测结果表明,污染区有相当高的酸性硫酸盐化速率、氟化物浓度和降尘量,分别是清洁医的15．4、17.5和28倍,明显高于国家排放标准。生长在污染区的大多数植物的净光合速率（Pn)、蒸腾速率(E)和气孔导度(gs)均出现不同程度的下降,下降幅度因植物种类不同而存在较大差异。Pn、E与gs之间存在一定程度的线性相关关系,但污染胁迫下Pn与gs线性相关的显著程度波削弱,而E与gs的相关性则得到提高,表现出不同植物种类Pn和E的变化与gs变化的不协同性、复杂性以及适应策略的多样性。根据Pn、E和水分利用效率(WUE)的变化,将植物对大气污染响应的敏感程度划分为：(1)高度敏感组,包括仪花、灰木莲、格木、阿丁枫、白桂木、海南木莲、白木香和海南红豆;(2)中度敏感组,包括幌伞枫、无忧树、红花木莲、小叶胭脂、蝴蝶树、山玉兰、灰莉、柳叶楠、刺果番荔枝、厚皮香、猫尾木、红桂木、竹节树、红花油茶、观光木、桂花、铁冬青、日本杜英、火焰木、铁力术和密仡树：(3)轻度敏感组,包括毛黄肉楠、华润楠、吊瓜木、大头茶、茶花、傅园榕、小叶榕、环榕、菩提榕和石笔木。     

7种木莲属植物抗寒性评价及其生理机制

为建立木莲属(Manglietia)植物的抗寒性综合评价体系,对7种木莲属植物扦插苗进行低温胁迫处理,测定叶片的抗寒性关键生理指标,拟合Logistic方程计算低温半致死温度,隶属函数法筛选抗寒性关键指标并综合评价。结果表明,7种木莲属植物的低温半致死温度依次为木莲红花木莲荷花木莲巴东木莲球果木莲锥花木莲粗枝木莲,且与相对电导率显著正相关。7种木莲属植物叶片的游离脯氨酸和可溶性蛋白含量及超氧化物酶、过氧化物酶活性均随温度降低呈先升后降的趋势,而可溶性糖和丙二醛含量则不断增加、后趋于平稳。聚类分析结果表明7种木莲可分为3类,木莲和红花木莲抗寒性较强;荷花木莲、巴东木莲和球果木莲抗寒性中等;粗枝木莲和锥花木莲抗寒性较弱。     

大气污染胁迫下9种植物幼苗叶片热值、C/N和灰分含量比较

用氧弹热值仪测定了生长在硫和氟复合污染环境和相对洁净环境下的9种木本植物幼苗叶片热值。结果表明,植物叶片的基础干重热值、灰分含量因种类不同而有差异,其中热值较高的(大于19．00kJ g^-1)植物有铁冬青(Ilex rotunda)、华润楠(Machilus chinensis)和仪花(Lysidice rhodostegia),热值中等的(介于18．00-19．00kJ g^-1)植物有复羽叶栾树(Koelreuteria bipinnata)、环榕(Ficus annulata)、乐昌含笑(Michelia chapensis)、小叶榕(Ficus microcarpa)和红花油茶(Camellia semiserrata),热值低的(低于18．00kJ g^-1)种类有火焰木(Spathodea campanulata)。大气污染导致复羽叶栾树、华润楠和铁冬青幼苗叶片基础干重热值增加,仪花、含笑、小叶榕、火焰木和红花油茶幼苗叶片基础干重热值下降,环榕基础干重热值则维持相对稳定。Pearson相关系数分析表明,9种植物幼苗叶片去灰分热值与叶片自身C／N比、叶片灰分含量的相关性均不显著,但污染胁迫下植物幼苗叶片热值相对波动程度与其对污染物的抗性有关,提示叶片热值可以作为植物幼苗对硫和氟复合污染的敏感性指标。     

抗SO2绿化植物的初步筛选

盆栽于广州市华南植物园内的72种城市绿化植物的叶片经模拟SO2(20mmol／L NaHSO3浸泡)处理后,研究其叶绿素荧光参数的变化,还比较了其中31种植物叶片的细胞液pH值和对碱缓冲能力的大小。通过对这些生理参数的分析,初步筛选出了一批抗污能力较强的树种,如：傅园榕(Ficus microcarpa var．fuyuensis)、红桂木（Artocarpus nitidus ssp.lingnanensis)、幌伞枫（Heteropanax fragrans)石笔木(Tutcheria spectabilis)等,和抗性较差的树种,如：印度第伦桃(Dillenia indica)、灰木莲(Manglietia glauca)、灰莉(Fagraea ceilanica)等。     

榕长尾小蜂属(小蜂总科,金小蜂科)研究和二新纪录种

记述金小蜂科榕长尾小蜂属Sycoscapter中国2新纪录种,Sycoscapter cornutus Wiebes,1981和S.keralensis（Abdurahi man＆Joseph）,1975。分别从采自海南儋州和陵水的小叶榕Ficus microcarpa L.榕果中育出。小叶榕为寄主新纪录。研究标本保存在中国科学院动物研究所动物标本馆。     

海南染木树茎的化学成分研究(Ⅰ)北大核心CSCD

研究海南染木树茎的化学成分,采用硅胶、Sehadex LH-20、ODS、HPLC等色谱技术对海南染木树茎乙醇提取物的乙酸乙酯部位进行分离和纯化,结合光谱数据和理化性质鉴定化合物的结构,分别为：4-甲基苯并喹啉-5,10-二酮（1）、白兰花碱（2）、鹅掌楸碱（3）、吲哚-3-甲醛（4）、羽扇豆醇（5）、霍烷-3,30-二醇（6）、熊果酸（7）、白桦酯酸（8）、30-羟基羽扇豆醇（9）、豆甾醇（10）、3β-乙酰基齐墩果醛（11）。其中,化合物4、7为首次从染木树属植物中分离得到,5、6、8、9-11为首次从该植物中分离得到。首次对化合物2的碳谱数据进行了归属。     

佛山市几种绿地植物氟化物时空累积特征

对佛山市的防护绿地、公园绿地、生产绿地及附属绿地等城市绿地系统中的大叶榕、细叶榕、芒果、白兰、垂叶榕和尖叶杜英的叶片和各绿地系统中的大气氟化物含量进行了测定,并对其相互关系进行了研究。结果表明:四季中各绿地系统的大气氟化物含量均值的大小依次为防护绿地的工业区、交通区、附属绿地、生产绿地和公园绿地;工业区的大气氟化物浓度约为公园绿地的3.4倍,不同城市绿地系统的1、2年生植物叶片含氟量均随时间的延长而逐渐增加;大气氟化物与叶片含氟量之间存在密切相关性,反映了植物氟化物的空间累积特征,其中细叶榕和垂叶榕的1年生和2年生叶片、芒果的1年生叶片、白兰的2年生叶片中的氟化物浓度能较好地表征城市绿地系统中大气氟化物的浓度。     

福建晋江常用园林树种综合评价分析

对福建晋江市建成区应用多年的常见乔木进行调查,从抗逆性、景观性、生态性、危害性、养护性等指标进行评价与分析,以了解这些园林树种在晋江地区的适应生长情况。评价结果表明,评为I级,其生态功能及观赏性较高,在城市园林绿化中可广泛推广应用的树种有小叶榕、海南蒲桃、香樟、大叶榕、高山榕、非洲楝、盆架子、菩提榕8种,Ⅱ级和Ⅲ级均有17种,Ⅳ级有7种。     

遮阴对三种木兰科幼苗生长和光合特性的影响

为探讨观光木、山白兰和灰木莲三种木兰科植物对不同光环境的光合适应机制,该文以其幼苗为材料,设置透光率分别为100% NS、72.3% NS、48.6% NS、24.9% NS的四种光照处理,测定其光合特性参数、生物量分配比例、叶绿素含量等,研究不同遮阴处理对其生长和光合作用的影响。结果表明:(1)过强或过弱的光照环境限制了幼苗株高及地径的生长,与全光照相比,72.3% NS有利于幼苗的形态生长。(2)随着遮阴程度的增加,观光木、山白兰和灰木莲幼苗的最大光合速率、光补偿点、光饱和点、暗呼吸速率、蒸腾速率逐渐降低,叶绿素含量增加,水分利用效率先升后降。(3)随着光强的减弱,观光木和山白兰地上部分的生物量积累增加,灰木莲的根生物量积累增加。(4)观光木的比叶面积随着遮阴程度的增加而先增后减; 灰木莲的比叶面积显著减小; 山白兰的比叶面积差异不显著; 观光木、山白兰和灰木莲对低光环境响应和适应的差异主要表现在生物量分配比例及叶的形态特征上。综上结果认为,72.3% NS最有利于幼苗的生长,观光木、山白兰和灰木莲在遮阴条件下可以通过降低P_max、LSP、LCP、R_d、T_r来增加叶绿素含量,适当调整生物量分配比例来增大光合能力,在中度遮阴时能增加水分利用效率、株高、地径来增大光合能力。     

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.     

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.     

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.