17种金线Ba核DNA含量及倍性的研究

采用血涂自、Feulgen染色和显微分光光度技术,测定了金线Ba属（Sinocyclocheilus）17个种的核DNA含量。结果显示,除侧条金线Ba(S.lateristritus）中采自云南沾益炎方山那边的样本之2C值为7.79 pg外,其余的核DNA 2C值都集中分布在4.19-4.86pg范围,大体与其近缘四倍体种2C值相同或相近,是其近缘二倍体种2C值的大约2倍 此我们推断,这17种金线Ba很有都是四倍体,个别种还含有八倍体的类型,金线Ba属可能是整属的四倍体起源。     

木兰科主要属种核DNA含量(2C-值)的检测

植物核DNA含量(2C-值)作为描述生物多样性的一个主要特征参量,对植物资源的研究具有重要意义。本文选取木兰科(Magnoliaceae)中10个代表性属,即木兰属(Magnolia)、含笑属(Michelia)、木莲属(Manglietia)、鹅掌楸属(Liriodendron)、盖裂木属(Talauma)、合果木属(Paramichelia)、观光木属(Tsoongiodendron)、华盖木属(Manglietiastrum)、单性木兰属(Kmeria)和拟单性木兰属(Parakmeria)下的23个种;以玉米(Zea mays)核DNA含量(5.45 pg/2C)为标准,通过流式细胞术测定各样品的核DNA含量(2C-值)。结果表明,23个种的核DNA含量从3.25 pg(3 178.50 Mbp)到13.61 pg(13 310.58 Mbp)不等;且CV值均5%。本研究结果可为木兰科中主要属下单元基因组大小的评估和其他植物核DNA含量的测定提供参考,同时也为木兰科植物资源的保护和利用研究奠定基础。     

基于流式细胞术的乌饭树核DNA含量(2C-值)测定

核DNA含量(2C-值)是描述植物生物多样性的一个重要特征参数。该研究利用流式细胞仪检测越橘属植物乌饭树核DNA含量,建立了适合乌饭树的流式细胞术测定方法:以野生乌饭树的嫩叶为材料,以已知核DNA含量的水稻品种‘日本晴’为内标,采用GPB解离液,细胞核悬液加入50μL獉mL-1碘化丙啶染色5 min即可上机检测。结果表明:(1) 9个乌饭树单株的核DNA含量平均值为(1.22±0.03) pg,最小值为1.18 pg,最大值为1.27 pg。(2)检测结果与已知的越橘属二倍体植株的2C-值含量相似,且不同地理来源的单株DNA含量没有显著差异(P0.05),推测这9个单株为二倍体植株。(3)测定的乌饭树核DNA含量(2C-值)可丰富越橘属植物的C-值库;基于流式细胞术建立的乌饭树核DNA含量测定方法可为该属其他植物的相关研究提供借鉴。     

GENOME SIZE

采用Feulgen-显微分光光度计方法,以鸡红细胞为标准DNA（3.22pg/2C）测定了长江白鲟、达氏鲟、中华鲟、史氏鲟和北美匙吻鲟的体细胞基因组大小（DNA含量）。结果表明,上述五种鲟鱼DNA含量分别为4.11、8.26、9.07、6.07和3.96pg。长江白鲟和北美匙吻鲟均属于四倍体鱼类,分布在长江水系的中华鲟和达氏鲟两种鲟属鱼类为八倍体类型。史氏鲟初步判断为八倍体,据分析可能存在四倍体的类型。根据所得到的结果并结合已发表的DNA含量和染色体资料,分析了鲟形目鱼类在细胞遗传上的进化特点。鲟形目鱼类全为多倍体起源的鱼类,在鲟形目的两科（白鲟科和鲟科）六个属中,除鲟属外,其他五个属均为四倍体,而鲟属已发现有四倍体、八倍体、十二倍体和十六倍体。说明在细胞水平的染色体加倍与鲟形目鱼类各科、属分化没有直接联系,只在鲟形目形成的早期和鲟形目形成后的鲟属种间分化中扮演着重要角色。鲟属鱼类的染色体剧烈分化可能是造成现今鲟属种类数最多（占整个鲟形目鱼类的65%以上）的重要原因。     

十四种淡水鱼的DNA含量

本实验采用血涂片,Feulgen染色,显微荧光光度法对分属4目7科的14种淡水鱼的红细胞核DNA含量进行了初步测定。在这些鱼类中,二倍体染色体数目和DNA含量存在着明显的相关性:2n=50左右的类型的DNA含量大多在2.0—2.9微微克(pg);而2n=100的鲤鱼和泥鳅则具有相对高的DNA含量,分别为3.5和4.6pg。分类地位较高的黄鳝和乌鳢具有较低的DNA含量,分别为1.6和1.3pg。鲤科鱼类中,染色体数目2n=50和2n=48的两种类型并不存在一致性的显著差异,这可能反映了这两类核型在进化上的近缘程度。泥鳅的DNA含量大约是大鳞付泥鳅的DNA含量(2.2pg)的2倍,证明了泥鳅是一种四倍体类型的鱼。     

DNA C-值与被子植物入侵性关系的数据统计分析——以中国境内有分布的539种被子植物为例

统计了中国境内有分布的539种被子植物的DNA C-值,分析了它们在不同分类群、生活型、倍性、生活史类型以及在杂草和非杂草类群中的分布情况,主要结果如下:(1)539种被子植物DNA C-值平均为4.06 pg,其中木本植物的DNA C-值平均为1.84 pg,低于草本植物的平均值(5.02 pg);(2)双子叶植物(360种)的DNA C-值平均为2.20 pg,极明显地小于单子叶植物(179种)的平均值(7.80 pg);(3)1年生植物的DNA C-值平均为2.78 pg, 明显小于多年植物的平均DNA C-值(6.65 pg);(4)134种杂草的DNA C-值平均为1.93 pg,明显小于非杂草草本植物的平均值(6.75 pg),含杂草较多的科,平均DNA C-值相对较小;(5)统计的47种入侵杂草的DNA C-值平均为1.76 pg, 略小于134种杂草的平均DNA C-值(1.93 pg),极显著地小于非杂草性草本植物(6.75 pg);(6)以科为单位,不同科的DNA C-值存在着极大的差异;(7) DNA C-值与染色体倍性的关系并不明显,但是,随着倍性的增加,基因组变小;(8) 在同一科、属中,与非杂草相比,典型杂草的DNA C-值往往偏小;(9)总体上杂草或杂草性强的植物,它们的DNA C-值比非杂草性植物的要小.但是,也还存在一些例外,例如野燕麦(Avena fatua)的DNA C-值就高达14.15 pg,而相反,十字花科和葫芦科的一些非杂草栽培植物,却具有很低的DNA C-值.结论:DNA C-值在预测外来物种的入侵性方面具有一定的应用价值,但是,由于在木本植物和草本植物之间、单子叶与双子叶植物之间、一年生和多年生植物之间,特别是在不同的科之间,植物的DNA C-值较明显的差异,因此,根据DNA C-值预测外来物种的入侵性,应该严格地限于同一科(或属)内的相关物种间的比较.     

中国西南六种广义拂子茅属( 禾本科) 植物的染色体数目

广义拂子茅属( Calamagrostis) 是一个世界温带广布的大属, 有些作者又分为拂子茅属和野青茅属, 但近期的研究表明处理为一个属较为合适。中国共有37 种广义拂子茅属植物, 但至今没有任何染色体的研究。本文报道了其中产于中国西南6 种野青茅的染色体数目, 其中Deyeuxia petelotii 4 个居群, D1 diffusa, D1 moupinensis, D1 nivicola 和D1f lavens 各一个居群都是四倍体( 2n= 4x= 28) , D1 neglecta 为六倍体( 2n= 6x= 42) 。根据广义拂子茅属植物染色体倍性特征, 该属植物中至今未发现二倍体, 四倍体是该属中倍性最低和最普遍的, 广义拂子茅属的演化很可能是在四倍体的水平上进行的。由于以上几个四倍体种均是狭域分布的类群, 所以可能是由四倍体的祖先隔离分化形成的。     

长江江豚基因组大小测定

本研究采用流式细胞术,以公鸡(Gallusdomesticus)红血细胞DNA含量为标准,测定了23头长江江豚(Neophocaenaphocaenoidesasiaeorientali)的基因组大小(或称C值)。实验过程中采用了保存在3中不同条件下的长江江豚的全血样品,用3种不同的方法提取白细胞。为了获得本实验所用的公鸡红血细胞DNA含量的准确值,首先以人(Homosapiens)的C值为标准,对其进行了校正。然后其C值(2C=2.35pg)用于长江江豚的基因组大小测定。结果发现:长江江豚的单倍体DNA含量为3.27pg/C,由此得出其基因组大小为3.17×109bp;雌性和雄性的C值分别为3.25pg和3.29pg,野外长江江豚和豢养长江江豚的C值分别为3.30pg和3.05pg。对雌雄个体之间以及不同生长条件下长江江豚的C值应用独立样本t检验分析,发现:1)不同性别的长江江豚基因组大小之间没有明显的差异;2)豢养条件下的长江江豚和野生长江江豚之间的基因组大小有明显差异,豢养条件下的长江江豚的基因组明显小于野生条件下的长江江豚。据此推测必要环境因子的变化可能会对长江江豚的基因组DNA含量造成影响。     

用显微分光光度术测定水稻根尖细胞核中DNA含量的分析

用显微分光光度术测定粳稻很尖组织细胞核中Feulgen－DNA含量,C值为0．322－2．651pg,较多集中在0.904－2．068pg,平均为1．469pg。说明报关组织中有不同倍性或多线性细胞,根组织分化过程中细胞核基因组复制特点不同。经秋水仙素处理不同时间后,核DNA含量相应增加,但核之间的含量差异仍然存在。根据核DNA含量的增加值,计算很尖细胞分裂周期平均为11．54h.     

斑鳢、乌鳢及其杂种细胞核DNA流式含量分析

以斑鳢(Channa maculata)、乌鳢(C.argus)及其正交杂种斑乌鳢(斑鳢♀×乌鳢♂)和反交杂种乌斑鳢(乌鳢♀×斑鳢♂)的红细胞为材料,以鸡(Gallus gallus)血细胞为DNA标准(2.5 pg/2c,2c指2倍体),采用流式细胞仪测定了这4种鱼的细胞核DNA含量。斑鳢、乌鳢、斑乌鳢及乌斑鳢这4种鱼血细胞DNA的绝对含量分别为(1.488±0.035)pg/2c、(1.489±0.034)pg/2c、(1.522±0.077)pg/2c和(1.520±0.033)pg/2c。斑鳢和乌鳢的细胞核DNA含量差异不显著(P0.05),斑鳢和乌鳢与两种杂交鳢的DNA含量差异显著(P0.05),两种杂交鳢之间的细胞核DNA含量差异不显著(P0.05)。杂交鳢细胞核DNA含量显著高于亲本,可以作为杂种鉴定的依据。     

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.     

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。     

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.     

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.