匙羹藤愈伤组织培养研究

以匙羹藤组培苗为外植体,研究茎段、茎尖和叶片以及不同植物生长调节剂组合对愈伤组织形成的影响;采用4因素4水平正交设计,用SPSS软件其结果进行分析。结果显示:各种外植体诱导愈伤的能力不同,依次是茎段、叶片。叶片诱导出非胚性愈伤组织,茎段、茎尖利于诱导胚性愈伤组织和胚状体;愈伤诱导的最佳培养基为MS+2,4-D 2.0 mg/L+6-BA 0.5 mg/L,诱导率为84.5%,愈伤生长旺盛,分裂快,颜色为淡黄色。愈伤组织分化成苗效果最好的条件是MS+NAA 1.0 mg/L+IBA 0.1 mg/L,分化率达到90.6%,最佳的生根条件是1/2 MS+NAA1.6 mg/L,生根率为100%。这为研究匙羹藤的组织的脱分化、分化以及胚状体的形成机制提供了参考。     

玉竹的组织培养与快速繁殖

以玉竹[Polygonatum odoratum (Mill.) Druce]根状茎、叶片和茎段为外植体,于附加不同激素配比的MS培养基中诱导愈伤组织、不定芽和不定根,探讨增殖培养和植株再生的条件.结果表明,叶片和茎段外植体诱导愈伤组织和芽的分化率很低;而根状茎外植体易于培养,有较高的诱导率和增殖倍数,其愈伤组织、不定芽和不定根的诱导率分别可达87%、90%和99%以上.适宜根状茎外植体愈伤组织诱导的培养基为MS+1.0 mg/L 6-BA+0.5 mg/L NAA,有利于增殖和丛生芽分化的培养基为MS+2.0 mg/L 6-BA+0.5 mg/L IBA和MS+3.0 mg/L 6-BA+0.1 mg/L NAA,而1/2MS+3.0～5.0 mg/L NAA适宜诱导试管苗生根培养.试管苗的移栽成活率可达85%以上.     

罗汉果不同器官直接分化再生苗的研究

以青皮果品种的叶片、叶柄和无芽茎段作为外植体,研究其直接分化再生苗能力的差异。结果表明:⑴MS 6-BA1.0mg/L IAA0.1mg/L和MS 6-BA2.0mg/L IAA0.1mg/L两组培养基均可使叶片外植体直接分化出芽并建成再生苗。叶片基部的分化能力最强,中部稍次,尖部最弱。⑵MS 6-BA3.0mg/L IAA0.1mg/L则诱导叶片外植体首先脱分化形成愈伤组织,继而再分化成再生苗,,且畸形苗居多,无应用价值。⑶叶柄和无芽茎段在三组培养基中都只能脱分化形成大量愈伤组织,难以分化再生苗。     

黄独脱毒苗叶片和茎段再生体系的建立

以黄独茎尖再生苗为试材,研究不同因素对黄独脱毒苗叶片和茎段再生体系的影响,以期对黄独脱毒苗的再生体系进行优化。结果表明,叶片和茎段诱导愈伤组织的最佳培养基是MS+KT 2 mg·L^-1+2,4-D 2 mg·L^-1;叶片和茎段诱导愈伤组织的最佳蔗糖浓度分别为30和50 g·L^-1;叶片和茎段在黑暗中较容易诱导出愈伤组织;叶片和茎段愈伤组织分化的最佳培养基是MS+KT 4 mg·L^-1+NAA 0.1 mg·L^-1;继代2次的叶片和茎段愈伤组织较容易分化;黄独不定芽生根的最佳培养基是1/2MS+IBA 0.1 mg·L^-1+NAA 0.5 mg·L^-1+PP₃₃₃ 1 mg·L^-1。本实验成功建立了黄独脱毒苗叶片和茎段的再生体系,为黄独脱毒苗的工厂化生产奠定了技术基础。     

生姜茎尖组织培养和快速繁殖研究

以生姜茎尖为外植体进行培养,筛选诱导愈伤组织和生根的最佳培养基。结果表明,在茎尖培养中,合理的消毒处理对茎尖成活率影响很大;以MS+6-BA 1.5mg/L+NAA 0.1mg/L为最适茎尖诱导培养基,可一次诱导形成愈伤组织,并直接形成带根幼苗,月增殖倍数为6.9倍,成活率76.9%。生姜腋芽继代培养基MS+6-BA 2.0mg/L+NAA 0.1mg/L+KT 1.0mg/L,以腐殖质土:菜园土=1:1基质可促进小苗后期生长,加速成苗。     

红叶石楠离体植株再生频率的影响因素研究

以红叶石楠带芽茎段及叶片为外植体,分析激素和培养条件等因子对愈伤组织诱导及植株再生的影响。结果表明,MS+0.10mg/L 2,4-D+0.50mg/L NAA+0.50mg/L 6-BA+0.50mg/L KT为最佳愈伤组织诱导培养基,暗培养的愈伤组织诱导率高于光培养,其愈伤组织诱导率可达100%(带芽茎段)和98%(叶片)。MS+0.50mg/L IBA+2.00mg/L 6-BA+2.00mg/L KT为最佳分化增殖培养基,分化率91%以上,增殖倍数6.8以上,均达到最高。1/2MS+0.50mg/L IBA+0.01mg/L NAA为最佳生根培养基,生根率92%,生根量4.4根/株,均达到最高。     

药用植物金荞麦愈伤组织诱导与植株再生

目前转基因技术已成为植物定向遗传改良的重要手段,而建立稳定高频的离体再生系统是实现遗传转化的基础和前提.本试验以25 ～30 d苗龄的金养麦(Fagopyrum dibotrys)无菌苗叶片、茎节间、叶柄为外植体进行愈伤组织诱导与植株再生研究.结果表明:叶片在MS +2,4-D 4.0 mg/L +6-BA 1.0 mg/L培养基上愈伤组织诱导率达到89％.茎节间在MS +2,4-D 2.0 mg/L +6-BA 2.0 mg/L培养基上愈伤组织诱导率为87％.叶柄在MS +2,4-D 4.0 mg/L +6-BA 2.0 mg/L+ IBA 0.2 mg/L培养基上的最高诱导率仅为54％.愈伤组织分化不定芽的适宜培养基为MS +6- BA2.0 mg/L +TDZ0.2 mg/L +NAA0.2 mg/L;金荞麦不定芽在1/2 MS +NAA 0.5 mg/L的培养基上生根效果最好.组培再生植株经炼苗后移栽到田间成活率达80％以上,且生长表现正常.高频完整再生体系的建立,为金荞麦进一步遗传操作和扩大药材资源奠定了基础.     

商陆离体再生体系的构建

目的:建立商陆离体再生体系。方法:选取商陆的幼茎、茎节、叶片、叶柄和顶芽为外植体,以MS作为基本培养基,通过添加不同浓度配比的植物生长调节剂分别进行愈伤组织、丛生芽和生根诱导,筛选商陆离体再生体系方案。结果:顶芽和幼茎为外植体诱导的愈伤组织出愈时间早,愈伤组织质量高,以培养基MS+6-BA0.5 mg/L+2.4-D 0.5 mg/L的诱导率最高,达到100%;其中,只有以顶芽产生的愈伤组织才能分化出丛生芽,芽分化培养基为MS+6-BA 2.0 mg/L+NAA 0.25 mg/L,诱导率为98%;诱导生根的适宜培养基为1/2 MS+NAA 0.3 mg/L,诱导率达100%。结论:建立和完善了商陆离体再生体系方案,为商陆遗传转化体系的构建奠定了基础。     

扁桃愈伤组织诱导及分化的研究

以扁桃优良品种'Naporeil'的茎段、叶片和花药作为外殖体,分别对其进行愈伤组织诱导和分化研究,以筛选愈伤组织的最佳诱导增殖培养基、分化培养基和生根培养基.结果表明,该品种以茎段、花药作为外殖体最易诱导获得愈伤组织,叶片不适宜作为外殖体诱导愈伤组织;愈伤组织的最佳诱导增殖培养基均为B5+0.5 mg/L 2,4-D+0.2 mg/L 6-BA+1.0 mg/L NAA,愈伤组织诱导率为100%,增殖倍数最高可达7倍;茎段愈伤组织的分化培养基为MS+0.2 mg/L NAA+0.8 mg/L 6-BA+0.5 mg/L ZT,分化率为71%;花药愈伤组织未见分化.由茎段愈伤组织再分化获得的不定芽在1/2MS+0.5 mg/L IBA培养基上诱导生根,并给以黑暗预处理可使生根率达80%以上.     

韭菜胚根高效植株再生体系的建立

为了建立韭菜高频植株再生体系,以韭菜胚根的不同部位为外植体,研究了不同部位愈伤组织和芽的诱导。结果表明,胚根尖为诱导愈伤组织的最佳外植体,愈伤诱导率达到81.4%,出芽率达到73.3%;比较在不同激素配方上的愈伤组织诱导和芽的分化,在MS+1 mg/L BA+0.5 mg/L NAA+0.5 mg/L KT培养基中再生率最高,诱愈率达到80%以上,不定芽分化率达78.8%,繁殖系数为24.7;在MS+1 mg/L GA+0.5 mg/L KT不定芽伸长培养基中,30 d不定芽伸长为独立植株,比例为85.5%;独立的韭菜苗在1/2MS+0.3 mg/L IAA中生根率及根系状况最佳。通过该方法 130 d左右即可从胚根脱分化再生出植株。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.