矮丛蓝莓叶片的愈伤组织诱导及植株再生

以矮丛蓝莓'Blomidon'品种的试管苗叶片为外植体,研究不同培养基、激素、转接时间以及转接方式对愈伤组织诱导及植株再生的影响.结果表明:WPM1/2为适宜的培养基;添加0.5 mg·L~(-1) CPPU+1.0 mg·L~(-1) ZT+0.5 mg·L~(-1) TDZ和0.5 mg·L~(-1) CPPU+0.5 mg·L~(-1) ZT+1.0 mg·L~(-1) TDZ诱导愈伤率较高达100%;ZT、CPPU与生长素IAA、IBA的配比诱导愈伤率效果不佳;添加ZT诱导的愈伤组织适合20 d后转接,CPPU诱导的愈伤组织适合50 d后转接;转接方式均以固体培养为宜.矮丛蓝莓'Blomidon'最适宜培养基为WPM1/2+0.5 mg·L~(-1) CPPU+1.0 mg·L~(-1) ZT+0.5 mg·L~(-1) TDZ,其诱导愈伤组织50 d后转接平均分化芽数最多达10.26个.     

藏药匙叶翼首草高频组织培养再生体系优化研究

以匙叶翼首草种子为材料,探索种子最佳消毒方法,对影响无菌苗外植体愈伤组织诱导、增殖及植株再生的因素进行了研究。结果表明:(1)剥去外种皮的种子,经75%乙醇1min+0.1%HgCl_27min+50%多菌灵500倍液30min消毒后,在1/2 MS培养基中的发芽率达60.67%,无污染。(2)无菌苗的叶片和茎段都适宜诱导愈伤组织,在培养基MS+5.0mg·L~(-1) 6-BA+2.0mg·L~(-1) 2,4-D中可在10d内诱导出生长旺盛的愈伤组织,愈伤诱导率分别为84.00%、97.33%。(3)适宜的愈伤组织增殖培养基为MS+3.0mg·L~(-1) 6-BA+2.0mg·L~(-1) IAA,培养20d的叶片和茎段愈伤组织的生长率分别为74.37%、70.52%。(4)适宜的丛生芽诱导培养基为MS+3.0mg·L~(-1) 6-BA+2.0mg·L~(-1) IAA+250mg·L~(-1) L-脯氨酸+150mg·L~(-1)水解酪蛋白,30d后茎段和叶片的丛生芽发生率分别达到100%、94.44%。(5)再生苗在1/2 MS+0.5mg·L~(-1) NAA培养基中生根培养30d,生根率为100%。匙叶翼首草高效稳定的再生体系为保护其野生资源和工厂化育苗提供了有效途径。     

轮叶党参的组织培养及植株再生研究

以轮叶党参为材料,研究了不同外植体、激素组合、培养基及光照条件对愈伤组织诱导及植株再生的影响.结果表明,叶片是轮叶党参组织培养较为合适的外植体.外植体在添加0.5 mg·L~(-1) 2,4-D+1.0 mg·L~(-1) 6-BA+0.5 mg·L~(-1) KT的MS培养基上愈伤组织诱导率最高可达100%;愈伤组织转移到附加0.75 mg·L~(-1) 6-BA+0.5 mg·L~(-1) NAA的MS培养基进行继代培养,增殖后的愈伤组织转移到附加0.5 mg·L~(-1) 6-BA+0.2 mg·L~(-1) NAA的1/2MS分化培养基进行分化,其分化率达89.4%;将分化出的芽转接到附加0.2 mg·L~(-1) IAA+0.2 mg·L~(-1) NAA的1/2MS培养基,生根率达92.5%.暗培养诱导出愈伤组织后转到16 h·d~(-1)光照条件下,愈伤组织增殖倍数和分化率显著提高,再生苗健壮,长势强.     

胡杨杂种叶片组培技术研究

目的:优化胡杨杂种叶片组培技术进而为其遗传转化研究奠定基础。方法:以胡杨杂种叶片为外植体,以WPM为基本培养基,研究不同植物生长调节剂对叶片诱导愈伤组织、愈伤组织诱导不定芽、以及不定芽进一步诱导不定根的作用效果。结果:胡杨杂种叶片最佳脱菌方式:0.1%HgCl_2脱菌5 min;叶片诱导愈伤组织的最适培养基为WPM+0.4 mg·L~(-1)6-BA+0.4 mg·L~(-1)NAA,诱导率可达100%;愈伤组织诱导不定芽的最适培养基为WPM+0.5 mg·L~(-1)6-BA+0.2 mg·L~(-1)NAA,诱导率可达100%;诱导不定根的最适培养基为1/2WPM+2.0 mg·L~(-1)IBA+0.02 mg·L~(-1)NAA+0.2 mg·L~(-1)GA_3,生根率可达100%。以上3种培养基均需添加30 g·L~(-1)蔗糖,30 g·L~(-1)琼脂,pH调至5.8。结论:本研究建立了以胡杨杂种叶片为外植体的组培技术,为后序进行胡杨杂种批量化生产及其遗传转化研究提供重要参考。     

羊草成熟胚诱导愈伤组织及植株再生系统的优化

羊草(Leymuschinensis)为异源四倍体禾本科牧草,利用成熟胚诱导愈伤组织获得再生植株的效率极低,难以运用遗传转化方法进行品种改良。我们以羊草成熟胚为外植体,使用适宜羊草愈伤组织生长的新型培养基配方,筛选诱导愈伤组织、不定芽分化及生根阶段的最适植物激素浓度、光照和温度条件,从而优化羊草成熟胚的组织培养方案。研究结果表明,羊草成熟胚诱导阶段2,4-D的最适浓度为2.0mg·L~(-1),变温暗培养,诱导率可达74.1%;分化阶段6-BA和NAA的最适浓度均为1.0 mg·L~(-1),分化率可达57.1%;生根阶段NAA的最适浓度为0.25 mg·L~(-1),移栽后成活率为100%。     

寿锦的离体植株再生及组培产业化增殖

以寿锦(Haworthia retusa×cooperi cv.‘Variegata’)的幼嫩花蕾为外植体,对其进行了离体植株再生及组培产业化增殖研究。结果显示,外植体在MS+5.0 mg·L~(–1) 6-BA+0.5 mg·L~(–1) IBA培养基上诱导产生愈伤组织;不添加激素的MS基本培养基最适宜寿锦愈伤组织的分化;再生芽在MS+0.2 mg·L~(–1) 6-BA培养基上增殖时,不定芽增殖率及斑锦类型不定芽的诱导率最高,分别为16.7和79.9%。研究结果表明,通过愈伤组织途径能够诱导寿锦不定芽的再生,适当浓度的细胞分裂素有利于提高寿锦的诱导率。研究结果对于珍稀斑锦多肉植物种质资源的保护及其产业化应用具有重要的指导意义。     

澳洲鸽子石斛组织培养快速繁殖研究

以澳洲鸽子石斛(Dendrobium kingianum Bidwill)幼嫩假鳞茎为外植体进行组织培养和快速繁殖研究。结果表明:采用合适的消毒方式,外植体消毒成功率可达92.5%。MS培养基添加5.0 mg·L~(-1) 6-BA适合用于不定芽的诱导和前期增殖,MS培养基+0.5 mg·L~(-1) NAA+2.0 mg·L~(-1) KT的增殖倍数最高,为6.96。丛生芽诱导出愈伤组织的最佳培养基为MS+0.25 mg·L~(-1) 2,4-D,诱导率为80%;愈伤组织分化的最佳培养为MS+1.0 mg·L~(-1) 6-BA,愈伤组织分化芽数为381.99个·g~(-1)。MS+2.0 mg·L~(-1) IBA+10%香蕉泥+1 g·L~(-1)活性炭最适合于生根壮苗培养;试管苗在兰石:泥碳土(1:1)的混合基质中移栽3个月后,成活率达100%,且生长速度快,基质成本较低,适合澳洲鸽子石斛试管苗的商业化栽培。     

射干真叶、花蕾诱导愈伤组织的研究

目的:建立射干愈伤组织的诱导体系。方法:采用MS培养基为基本培养基,研究不同浓度激素配比及不同AgNO_3浓度对射干真叶、花蕾诱导愈伤组织的影响,并利用显微技术鉴定其愈伤组织类型。结果:射干无菌苗真叶愈伤组织诱导的最佳培养基为:MS+2,4-D 1. 0 mg·L~(-1)+6-BA 1. 5 mg·L~(-1)+NAA 1. 0mg·L~(-1)+AgNO_315mg·L~(-1),花蕾愈伤组织诱导的最佳培养基为:MS+2,4-D 1. 0 mg·L~(-1)+6-BA 1. 0 mg·L~(-1)+NAA 1. 0 mg·L~(-1),诱导率均高于60%,其中2,4-D对射干愈伤组织诱导至关重要,AgNO_3对射干真叶胚性愈伤组织的形成有一定的影响。结论:花蕾是射干愈伤组织诱导较理想的外植体材料,获得的高效愈伤组织诱导条件将为后续射干细胞悬浮体系的成功构建奠定基础。     

藏药山茛菪组织培养技术研究

以田间栽培两年生山莨菪幼芽(休眠芽)、带叶柄幼叶为外植体,通过器官培养分化芽的途径达到快速繁殖的目的。MS基本培养基附加NAA0～1.0mg·L~(-1)+6-BA2.0～3.0mg·L~(-1)+ZT0～3.0mg·L~(-1),适于丛生芽的诱导与增殖;附加2,4-D2.0mg·L~(-1)+NAA0.2mg·L~(-1)+6-BA0.2mg·L~(-1),适于愈伤组织的诱导与继代培养,诱导率高达93.2%;1/2MS培养基附加NAA1.0mg·L~(-1)+3.0%的蔗糖,适于生根诱导,生根率为100%。     

红花草莓的组织培养与快繁技术研究

以红花草莓叶片为外植体,通过筛选诱导愈伤组织、不定芽及壮苗、生根的培养基,建立一套实用且易推广的红花草莓组培快繁技术体系。结果表明:在愈伤组织的诱导过程中TDZ的诱导效果优于6-BA,TDZ与NAA配合使用效果优于与IBA的组合。6-BA浓度为0.5 mg·L~(-1)时不定芽诱导率高达86.6%。低浓度的6-BA和8 g·L~(-1)的琼脂更有利于壮苗培养,NAA比IBA更有利诱导生根。综上述,最适红花草莓愈伤组织的诱导培养基为MS+1.0 mg·L~(-1)TDZ+0.5 mg·L~(-1)NAA+30 g·L~(-1)蔗糖+7 g·L~(-1)琼脂;最适不定芽分化的培养基为MS+0.5 mg·L~(-1)6-BA+0.1 mg·L~(-1)NAA+30 g·L~(-1)蔗糖+7 g·L~(-1)琼脂;最适壮苗培养基为MS+0.1 mg·L~(-1)6-BA+0.1 mg·L~(-1)NAA+30 g·L~(-1)蔗糖+8g·L~(-1)琼脂;最适生根培养基为MS+0.5mg·L~(-1)NAA+30 g·L~(-1)蔗糖+8 g·L~(-1)琼脂。试管苗移栽生长20 d后,成活率高达93%,且后期草莓苗生长壮健。此体系的建立为优质红花草莓种苗大规模生产提供了科学依据和技术支持。     

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.