木兰科13个分类群和12个杂交组合的染色体数目

对木兰科Magnoliaceae 13个分类群的染色体进行了计数, 其中落叶木莲Manglietia decidua、香港木兰Magnolia championii、馨香玉兰Magnolia odoratissima、香木兰Magnolia guangnanensis等12个种的染色体数目为首次报道。同时对木兰科属内属间的12个人工杂交组合的后代进行了染色体鉴定,其中,二乔玉兰红元宝Magnolia×soulangeana“Hongyuanbao” (♀,2n=4x=76)与云南含笑Michelia yunnanensis (♂,2n=2x=38)、红元宝与金叶含笑Michelia foveolata(♂,2n=2x=38)杂交后代的染色体为2n=3x=57,为其亲本染色体半数之和,证明这两个远缘杂交后代为真实杂种。     

玉兰减数分裂观察及染色体构型分析

采用去壁低渗方法,观察研究了玉兰Magnolia denudata有丝分裂和减数分裂的细胞学特征。实验结果证实玉兰存在两种染色体倍性,即2n=4x=76和2n=6x=114。通常,在木兰属甚至整个木兰科每个物种只具有一种染色体数目。玉兰有丝分裂间期核为复杂染色中心型,其中期染色体较小。玉兰在减数分裂中期I的构型表现出多样性,其中最主要的特点是比同源多倍体预期的二价体出现的频率更高些,其次是在减数分裂中期I可以观察到1或2个环状和（或）链状六价体。这些特征与同源异源六倍体或部分的异源六倍体种北美红杉Sequ     

加拿大披碱草×野大麦三倍体杂种染色体的分子原位杂交鉴定

加拿大披碱草与野大麦 2个四倍体多年生禾草杂交产生的属间杂种F1为三倍体 (2n =3x =2 1) ,丢失了与亲本染色体基数相同的 7条染色体。为查明该杂种F1的染色体构成 ,应用基因组分子原位杂交方法 ,将父本(♂ )野大麦基因组 (H1H1H2 H2 )DNA用荧光生物素标记作为探针 ,以母本 (♀ )加拿大披碱草基因组 (SSHCHC)DNA作为封组 ,对杂种F1根尖细胞有丝分裂中期的染色体DNA进行原位杂交。结果表明 :三倍体杂种F12 1条染色体中 ,有 14条出现偏黄色荧光信号 ,来自父本 (♂ )野大麦H1H2 基因组有 7条出现橙红色荧光信号 ,来自母本 (♀ )加拿大披碱草S基因组、加拿大披碱草HC 基因组的 7条染色体丢失。     

5种木兰科植物的DNA-C值及倍性分析

以紫玉兰为内标或外标,利用流式细胞术测定了杂交马褂木(Liriodendron chinense×tulipifera)、深山含笑(Michelia maudiae)、长蕊含笑(Michelia longistamina)、广玉兰(Magnolia grandiflora)和二乔玉兰(Magnolia soulangeana)5种木兰科植物的DNA-C值及倍性。结果表明,两种含笑属植物及杂交马褂木均为二倍体,广玉兰为六倍体,二乔玉兰为四倍体,5种植物的C值各不相同,最大的是广玉兰,最小的是杂交马褂木,它们的C值大小属于小到中等水平。     

中国木兰属部分种的核型分析

对我国木兰属（Ｍａｇｎｏｌｉａ）１２个种的核型进行了分析,ｘ＝１９,厚朴、凹叶厚朴、红花山玉兰、山玉兰、天目木兰、夜合为二倍体,２ｎ＝２ｘ＝３８;紫玉兰、玉兰、玉堂春为四倍体,２ｎ＝４ｘ＝７６;乐东木兰、荷花玉兰、狭叶荷花玉兰为六倍体,２ｎ＝６ｘ＝１１４,该属具有属内多倍体（次生多倍化）。核型分析结果表明：木兰属种间核型差异较小,大部分为中部着丝粒染色体（ｍ）,少数为具近中部着丝粒染色体（ｓｍ）,二倍体种中只有一对具近端部着丝粒染色体（ｓｔ）,其核型均为２Ｂ型。     

木兰科植物染色体数目报道

木兰科5种（含笑属4种、木莲属1种）、1杂交种植物染色体基数均为x=19,且都是二倍体2n=38,未见多倍体和非整倍体.其中4种和1杂交种的染色体数目为首次报道.     

不同倍性鱼的血细胞和精子DNA含量比较

我们以前的研究表明, 以红鲫 (2n=100) 为母本及湘江野鲤 (2n=100) 为父本的杂交后代的F1-F2 为二倍体 (2n= 100)。在二倍体 F2 个体中, 存在能分别产生二倍体卵子和二倍体精子的雌、雄个体, 二倍体卵子和二倍体精子结合, 形成了两性可育的四倍体鱼 (F3)。目前四倍体鲫鲤已连续繁殖了 12 代 (F3-F14), 形成了一个遗传性状稳定的四倍体鱼群体 (4n= 200) (Liu et al.,2001; 孙远东等, 2003)。雌性四倍体鲫鲤产生的二倍体卵子经紫外线照射的散鳞镜鲤精子激活后,无须染色体加倍处理, 可发育为全雌性二倍体雌核发育后代 (G1) (2n=10…     

远缘杂交形成的二倍体鱼和多倍体鱼生殖细胞染色体研究

本文采用性腺染色体制片及组织学切片方法,系统地研究了不同发育时期的鲫鲤杂交第二代(F2) (2n=100)、异源四倍体鲫鲤(4n=200)、三倍体鲫鱼(3n=150))、雌核发育二倍体鲫鲤第二代(G2)(2n=100)及鲤鱼(Cypninus carpio L)(2n=100)(对照组)生殖细胞的染色体特征.研究结果表明,对照组中鲤鱼精原细胞染色体数与体细胞染色体数一致,为二倍体精原细胞(2n=100),而远缘杂交形成的二倍体鱼和多倍体鱼的生殖细胞中则观察到明显的染色体数加倍现象,其中,鲫鲤杂交第二代(F2)精巢生殖细胞染色体数加倍现象特别丰富,占检测的染色体分裂相的21.6%,为其产生不减半的二倍体配子提供了直接的细胞学证据,同时也说明远缘杂交是导致生殖细胞染色体数加倍的一个重要因素.该研究在探讨多倍体鱼的发生及鱼类遗传育种方面具有重要意义.     

六倍体多星韭的发现及多星韭种内倍性组成及演化的分析

采用染色体常规制片技术,对云南西北部和中部地区11个多星韭居群进行了细胞学分析。结果显示:(1)云南西北部多星韭二倍体、四倍体混合分布的太子阁和华首门四倍体居群中发现了三倍体(2n=3x=21),核型公式分别为:2n=3x=21=[6m(2sat)+8sm]+(3m+4sm)和2n=3x=21=[4m(2sat)+10sm]+(2m+4sm+lst)。三倍体含2条随体染色体,它的21条染色体含2个同源染色体组和一个与它们同源性稍差的染色体组。(2)在云南中部的多星韭四倍体居群中首次发现了六倍体,核型公式为2n=6x=42=15m(3sat)+27sm,核型类型2A。(3)结合核型特征及地理分布对多星韭三倍体和六倍体的成因进行分析,提示多星韭三倍体来源于二倍体与四倍体的杂交,六倍体是通过四倍体产生的未减数配子(n=4x=28)与正常减数配子(n=2x=14)的结合形成的。本研究结果支持多星韭的分化中心是云南西北部高海拔地区的观点,并结合前人的研究和本工作的结果,对多星韭种内的倍性组成和演化进行了分析和讨论。     

''土佐文旦''胚囊发育及其子代体细胞染色体的观察研究

选取母本‘土佐文旦’不同时期的花蕾及文旦杂交F1子代3~5 mm长的幼叶,采用石蜡制片法及柑橘染色体制片技术,观察不同时期母本子房结构及杂交F1子代体细胞染色体数目。结果显示:(1)追踪到母本大孢子的发生及不同时期胚囊的发育特征,获得了杂交F1子代清晰可靠、分散良好的体细胞染色体图像,母本石蜡切片观察结果为进一步确定2n雌配子的最佳诱导期提供依据;(2)杂交F1子代体细胞染色体观察结果表明,杂交F1子代中既有正常的二倍体也有三倍体,为进一步原位杂交技术及确认2n配子类型和可能的遗传效应奠定了基础。     

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.     

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.     

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.     

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.     

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。     

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.     

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.