睡菜离体快繁技术的研究

以睡菜的幼嫩茎段为外植体,接种到附加不同浓度激素配比(6-BA/NAA)的MS培养基,诱导睡菜愈伤组织、芽及根的生长。研究发现,外植体在1.0mg/L 6-BA+0.1mg/L NAA+MS的培养基上培养10d,可观察到浅绿色的愈伤组织。愈伤组织转接到4.0mg/L 6-BA+0.3mg/L NAA+MS培养基上2周左右可生成芽。对带芽的愈伤组织再进行诱导生根进而形成完整再生植株,最适根诱导培养基为0.3mg/L 6-BA+1.0mg/L NAA+MS培养基。该实验采用植物离体快繁技术成功建立了睡菜再生体系,为睡菜种苗规模化奠定了技术基础。     

皂质芦荟的组织培养

将皂质芦荟的茎段及幼苗作为外植体进行组织培养,试验结果表明：皂质芦荟的茎段经40d左右可诱导形成愈伤组织,再经20d萌生再生芽：幼苗培养需要30d左右基部直接分化再生芽。同时经试验筛选出愈伤组织形成、再生芽分化和生根的最适培养基为：MS＋6－BA 2.0mg/L NAA 0.1mg/L、MS 6-BA 3.0mg/L NAA 0.1mg/L和MS NAA 0.3mg/L。     

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.     

冬凌草离体培养体系的建立及主要次生代谢产物的测定

以冬凌草叶片为外植体,研究不同浓度激素组合对冬凌草愈伤组织诱导及植株再生的影响,并对不同外植体(茎、叶)诱导愈伤、芽的分化能力及再生植株内主要次生代谢产物的含量进行了比较研究。结果表明:在MS 2.0 mg/L 6-BA 1.0 mg/L NAA培养基上诱导愈伤组织效果较好;在MS 2.0 mg/L 6-BA的培养基上诱导芽的效果较好;叶片和茎段在愈伤诱导培养基上均能产生大量的愈伤组织,但其再分化能力以茎段最好;再生苗生根培养基以0.3 mg/L IBA最好;以叶为外植体诱导的再生植株中冬凌草甲素、迷迭香酸的含量均高于以茎为外植体诱导的再生植株。     

仙人掌果的组织培养

以仙人掌果的植株顶端幼嫩茎段为外植体,在添加NAA 0.5mg/L+6-BA 5.0mg/L的MS培养基中诱导产生丛生芽,在此培养基上继代培养,丛生芽数不断增加。在添加NAA 0.2mg/L+IBA 1.0mg/L的MS培养基上可正常长根。     

湖北双蝴蝶的组织培养研究

以湖北双蝴蝶带芽茎段、不带芽茎段及叶片为外植体,以MS为基本培养基,通过添加不同的植物生长物质种类和浓度配比,建立湖北双蝴蝶组培快繁体系。结果如下:在所有实验方案中,带芽茎段的出愈率最高,是理想的离体快繁材料。较适宜的初代培养基为MS+BA2.0mg/L+蔗糖3.0%,增殖培养基为MS+BA2.0mg/L+NAA0.1mg/L+蔗糖3.0%,而根的诱导则在1/2MS+NAA0.5mg/L+蔗糖1.5%的培养基上进行较为适宜。同时对组织培养过程中湖北双蝴蝶植株再生的方式进行了讨论。     

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。     

川芎高频再生体系的建立

为建立川芎(Ligusticum chuanxiong Hort.)高频再生体系,优化了诱导和分化培养基及培养条件.以叶柄为外植体,以MS为基本培养基,KT2.0 mg/L+ IAA0.5mg/L的激素组合对不定芽分化最有利.在此基础上,针对外植体来源、培养条件和愈伤组织继代时间3个因素进行优化.结果表明:采用川芎无菌苗叶柄作为外植体,黑暗条件下诱导出愈伤组织,再在光照下继代培养15d后转入分化培养基中对不定芽诱导最为有利,分化率为44.4％.分化后得到的不定芽在含NAA0.5 mg/L和IBA 0.5 mg/L的1/2MS培养基上生根率达90％,移栽存活率为95％.     

强德勒红心柚离体培养与植株再生体系的建立

以强德勒红心柚（Citrus grandis Osbeckcv. Chandler）种子萌发的无菌苗为材料,选取子叶、子叶节段、上胚轴、带芽的茎段进行离体培养研究。结果表明：子叶节段是诱导丛生芽的最佳外植体,诱导率100%;诱导丛生芽的最佳培养基为MS＋6-BA2.0mg/L＋NAA0.05mg/L＋蔗糖30g/L＋活性炭0.4g/L,丛生芽增殖可达11.2倍;最适生根培养基为1/2MS＋NAA0.5mg/L,生根率达100%,移栽15d后成活率100%。     

连钱草组培快繁技术研究

用连钱草无菌茎尖为外植体进行快速繁殖,分别诱导、分化、生根形成再生植株进行快速繁殖,并移栽成活。结果表明在MS+6-BA1.5mg/L+NAA0.1mg/L培养基上诱导丛生芽效果最佳。在MS+IBA1.0mg/l+KT1.0mg/L培养基中根的诱导率为100%。     

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.