同色兜兰的非共生萌发与快速繁殖研究

以授粉后不同发育时期的同色兜兰种子为材料,观察其形态特征和萌发过程,并探讨建立同色兜兰高效快繁体系的最佳条件。结果表明,种子发育中后期即授粉后210~240d为较适宜的采收期,授粉后210d的种子萌发率最高(达77.79%);1/4 MS和1/2MS为同色兜兰适宜的基本培养基,添加100mL/L椰乳或1g/L蛋白胨对种子萌发及原球茎生长和分化有明显的促进作用;添加1g/L活性炭对原球茎褐化有一定的抑制作用,但添加剂量不宜过大;添加香蕉汁和苹果汁对同色兜兰种子萌发和原球茎生长分化有抑制作用;暗处理对同色兜兰种子萌发无影响;分化后的原球茎在壮苗和生根培养基上培养120d即可得到4~5片叶、高3~5cm的同色兜兰健壮试管苗。     

纹瓣兰的无菌播种与试管成苗

纹瓣兰作为一种野生的兰花资源有其重要的保护及保存意义,本试验以纹瓣兰的种子作为外植体对其进行无菌播种,并成功诱导出再生植株.试验结果表明,在添加椰子水和6-BA的1/2MS培养基中纹瓣兰的种子可以在较短的时间内形成原球茎,其中以添加6-BA 2.0 mg/L+10%椰子水诱导效果最佳.添加6-BA 0.5 mg/L+NAA 0.2 mg/L的1/2MS培养基最有利于纹瓣兰芽的分化,在分化培养50 d时其分化率可达到100%,且芽生长健壮.当生根培养基为1/2MS+NAA 0.1 mg/L时,纹瓣兰的生根率达95%;生根培养30 d后移栽,幼苗成活率达90%以上.     

白旗兜兰种子非共生萌发与试管苗快速繁育

对我国极小种群野生植物白旗兜兰的种子非共生萌发与试管苗快速繁育开展研究,对比了不同培养基、预处理、种子成熟度及光照对种子萌发的影响。白旗兜兰种子萌发的最适条件是授粉后270 d的种子,在1/4MS+10%椰汁培养基上,用1%Na OCl溶液处理种子40 min并在播种后的前4周进行黑暗培养。最适合原球茎转化幼苗的培养基是3.0 g·L-1花宝一号+1.0 mg·L-1NAA+0.5 g·L-1活性炭+10%香蕉匀浆,而最佳幼苗生根壮苗的培养基是3.0 g·L-1花宝一号+1.0 mg·L-1NAA+1.0 mg·L-16-BA+0.5 g·L-1活性炭+10%香蕉匀浆。     

豆瓣兰的无菌播种与快速繁殖

1植物名称豆瓣兰[Cymbidum serratum（Schltr）Y.S.Wu et S.C.Chen]。2材料类别种子。3培养条件种子萌发培养基：（1）MS＋1 mg·L-（-1）BAP＋10%椰子水;（2）改良Kyoto＋1 mg·L-（-1） BAP＋10%椰子水;（3）1/3MS＋1 mg·L-（-1） BAP＋10%椰子水。原球茎增殖培养基：（4）改良Kyoto＋2 mg·L-（-1）BAP＋1 mg·L-（-1） NAA＋10%椰子水。根状茎增殖培养基：（5）改良Kyoto＋3 mg·L-（-1） BAP＋0.2 mg·L-（-1） NAA＋10%椰子水。分化壮苗培养基：     

橙黄玉凤花种子萌发培养及小苗组培快繁研究

对橙黄玉凤花Habenaria rhodocheila种子进行无菌萌发培养以获得大量原球茎,并对原球茎组培,建立其快繁体系。结果表明,橙黄玉凤花种子以0.1%升汞消毒15 min为最佳处理。种子萌发培养基中,添加0.2%活性碳(AC)有利于种子萌发。种子萌发的最佳培养基为1/2MS＋NAA 0.5 mg·L-1＋AC 0.2%,原球茎增殖分化最佳培养基为1/2MS＋NAA 0.2 mg·L-1＋ZT 3.0 mg·L-1＋AC 0.2%;生根最佳培养基为1/2MS＋NAA 0.1 mg·L-1＋6-BA 2.0 mg·L-1＋AC 0.2%。     

安诺兰无菌播种组培快繁技术研究

安诺兰(Anota hainanensis)种子无菌播种试验表明:在MS+6-BA 0.1 mg/L培养基上种子能形成原球茎团;1/2 MS培养基有利于原球茎增殖,加6-BA 1.0 mg/L+NAA 0.1 mg/L原球茎增殖效果较佳,增殖率达793.3%;在1/2 MS+IBA 1.0 mg/L+2.0 g/L活性碳+100 g/L香蕉匀浆+100 ml/L椰子水的培养基上,试管苗生根效果最好;试管苗移栽至椰糠上,成活率达91.4%。     

西藏虎头兰高效植株再生体系的研究

为建立西藏虎头兰(Cymbidium tracyanum)的高效快速繁殖体系,该研究以野生西藏虎头兰种子为外植体,通过分析不同基本培养基和植物激素配比对原球茎诱导、增殖和分化的影响,以及光照时间和培养温度对试管苗生长的影响,筛选出适宜西藏虎头兰植株高效再生的条件。结果表明:适宜西藏虎头兰生长的基本培养基为1/2 MS;种子萌发和原球茎诱导的最适培养基为1/2 MS+1.0 mg·L~(-1)6-BA+0. 5 mg·L~(-1)NAA,培养50 d后,有95.00%的种子发育成原球茎;原球茎增殖的最适培养基为1/2 MS+2.0 mg·L~(-1)NAA,培养30 d,增殖倍数为4.25;原球茎的最适分化培养基为1/2 MS+2.0 mg·L~(-1)NAA+60 g·L~(-1)土豆泥+0.5g·L~(-1)活性炭,培养10 d,不定芽发生率为98.33%,培养40 d,幼苗生根率为94.67%;试管苗在温度20℃、光照时间12 h·d~(-1)、光照强度2 000 lx的条件下培养,苗长势好,叶片生理性焦尖发生率仅为3.33%;以腐殖土作为栽培基质,试管苗的移栽成活率为97.78%。该研究结果为保护西藏虎头兰野生资源和工厂化育苗提供了科学依据和技术支持。     

不同培养基上白芨的种子萌发与幼苗形态发生

对无菌条件下白芨种子在不同培养基上的萌发及其幼苗形态发生进行了研究.结果表明:在白芨种子萌发过程中,种胚先转绿,然后在种胚远离残余胚柄的一端突破种皮,形成原球茎.在原球茎顶端分化出叶原基,并逐渐发育成叶片.在原球茎下部表面存在透明的毛状物,推测这些毛状物与幼根根毛是同功的.白芨种子萌发最适培养基为1/2 g·L-1 +1.0 mMS NAA.添加低浓度的外源细胞分裂素(6-BA或KT)与NAA组合均严重抑制种子的萌发,种子萌发率较低,形成的圆球茎较小,原球茎分化出的小苗也较细弱.白芨生根壮苗最适培养基为1/2 g·L-1 NAA+2.0 g·L-1活性炭+1.0 mg·L-1 +1.0 mMS GA3.生根壮苗培养基中加入活性炭和GA3有利于根的生长和壮苗,且植株长势健壮.炼苗基质为腐殖土和蛭石(1∶1),成活率可达90%以上.     

铁皮石斛快速繁殖和离体种质保存的研究

对铁皮石斛种子发芽、原球茎增殖、丛芽分化和壮苗培育进行了试验、观察和分析,研究了培养基、植物激素、光强和添加剂等对其分化和生长的影响。结果显示种子在1/2MS+蔗糖2%的培养基上,30d萌发95%以上。原球茎在1/2MS+椰子汁25%+蔗糖3%的培养基上,45~60d原球茎增殖速度可达1∶10。丛芽分化较适宜的培养基为1/2MS+BA2mg·L-1+NAA0.2mg·L-1+IBA0.1mg·L-1+蔗糖3%,45~60d芽丛增殖速度为1∶4~5。试管苗在MS+香蕉泥20%+蔗糖2%培养基上,大约60d苗快速长高,茎粗壮且根系发达。离体保存材料可采用试管丛芽和原球茎两种方式,以保持其遗传多样性。保存方法是在15℃左右条件下,保存离体材料,继代间隔期为12~18个月;也可以采用室温保存,在1/2MS+蔗糖1%培养基上,继代间隔期可延长至10~12个月。     

白花独蒜兰的组织培养和快速繁殖

1植物名称白花独蒜兰(Pleione allbiflora). 2材料类别种子、原球茎. 3培养条件种子播种培养基:(1)KC[1] CM 100mg·L-1(单位下同) AC 2 g.L-1.拟原球茎诱导培养基:(2)MS NAA 1.0;(3)MS 6-BA 1.0;(4)MS NAA 1.0 6-BA 0.2;(5)MS NAA 0.2 6-BA 1.0.生根壮苗培养基:(6)Hypenox2号(N:P:K=20:20:20,美国Hyponex化学公司产品)2 g.L-1 NAA0.5 香蕉匀浆100 ml.L-1 AC 2 g.L-1.以上培养基分别附加1.5%蔗糖、0.8%琼脂,pH5.4.培养温度(25±1)℃,光照度1 000～1 500lx,光照时间14 h·d-1;种子播种后暗培养2周,再转入光下培养.     

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.