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.     

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.     

栀子带芽茎段愈伤组织诱导分化及丛生芽增殖和生根研究

以栀子带芽茎段为试材,对其愈伤组织诱导分化及丛生芽增殖与生根进行初步研究。结果表明,栀子带芽茎段愈伤组织快速诱导和分化最佳培养基是MS+KT 1 mg/L+NAA 0.05 mg/L;栀子带芽茎段丛生芽增殖和生根最佳培养基是MS+KT 2.0 mg/L+NAA 0.05 mg/L。     

红掌茎段侧芽离体快繁技术研究

以红掌嫩茎为外植体,诱导侧芽萌发,并进行增殖和生根培养,研究不同生长调节剂浓度配比对茎段侧芽萌发、增殖、无菌苗生根的影响以及增殖培养过程中愈伤组织的抑制等因素。结果表明,侧芽诱导的适宜培养基为MS+6-BA 2.0 mg/L+NAA 0.5 mg/L,萌发率达87.5%;最适增殖培养基为MS+6-BA 0.8 mg/L+NAA 0.2 mg/L+VB2 8.0 mg/L,增殖系数3.8;最适生根培养基为1/2MS+NAA 0.5 mg/L,生根率98%;在增殖培养基中添加适量VB2能较好地抑制愈伤组织的生成,防止愈伤组分织分化形成芽,从而达到以芽繁芽的目的。     

矮生龙船花的组织培养和快速繁殖

矮生龙船花(IxoracoccineaL.)的带节茎段在MS 2,4D2.0mg/L培养基上产生大量的愈伤组织;在MS 6BA1.0mg/L NAA0.2mg/L培养基上芽的增殖系数达413,并产生少量的愈伤组织;在MS NAA0.2～2.0mg/L培养基上只产生芽而无愈伤组织形成。愈伤组织在MS 6BA0.5mg/L NAA0.5mg/L培养基上产生大量的不定芽,丛生芽在MS 6BA0.5mg/L NAA0.5mg/L培养基上生长较快并产生较多分枝,将分枝节下或切成段后在MS 6BA0.5mg/L NAA0.5mg/L培养基上能迅速生长并产生新的分枝。试管内小苗在1/2MS NAA0.5mg/L培养基上的生根壮苗效果较好。矮生龙船花试管苗成活率为935%。     

紫色大花矮牵牛组织培养与植株再生

矮牵牛叶片外植体在MS+6-BA 1.0mg/L+NAA 0.1mg/L培养基上培养3周后产生致密的浅绿色愈伤组织;转入芽分化培养基MS+6-BA 0.5mg/L+4-PU 0.5mg/L+NAA 0.1mg/L 1周后,从愈伤组织表面不断分化产生幼芽;待幼芽长至3cm时转接至生根培养基1/2MS+NAA 1.0 mg/L+GA₃0.5mg/L中生根,长成完整植株。     

防风愈伤组织诱导及其分化研究

[目的]研究防风愈伤组织形成和分化的适宜条件,为优良品种的培育奠定基础。[方法]以防风幼苗为材料,进行愈伤组织诱导和分化研究。[结果]以茎段为外植体在黑暗下诱导愈伤组织分化最佳;在黑暗条件下继代,最佳培养基为MS+2,4-D 0.6 mg/L+6-BA 0.4 mg/L+KT 0.6 mg/L。光暗交替下MS+1.0 mg/L KT+0.4 mg/L NAA和MS+NAA 0.2 mg/L+6-BA 0.4 mg/L+KT 0.6 mg/L为最佳丛生芽诱导培养基;黑暗下MS+NAA 0.6 mg/L+6-BA0.5 mg/L和MS+NAA 1.0 mg/L+KT 0.6 mg/L为最佳不定根诱导培养基。且MS+NAA 1.0 mg/L+6-BA 0.5 mg/L和MS+NAA 0.6 mg/L+6-BA 0.4 mg/L+KT 0.2 mg/L均有利于防风丛生芽的诱导,NAA 0.2 mg/L+IAA 0.2 mg/L+IBA 0.2 mg/L有利于防风不定根的形成。[结论]成功诱导防风愈伤组织并分化出丛生芽和不定根,为再生体系建立和规模化培养提供技术支撑。     

金线莲外植体筛选及愈伤组织诱导研究

以金线莲茎段、叶片、茎片、不定芽为试材,分别在添加6-BA、ZT、NAA、KT 5个不同处理的MS及1/2MS培养基上培养,诱导愈伤组织。结果表明,以茎段、茎片、不定芽为外植体,在MS + 6-BA 2.0 mg/L + NAA0.5 mg/L、MS + NAA 2.0 mg/L + KT 0.1 mg/L和MS + 6-BA 2.0 mg/L + NAA 0.5 mg/L + ZT 0.2 mg/L培养基中培养,均能成功诱导愈伤组织。不定芽为诱导愈伤组织最佳外植体,最佳培养基为MS + 6-BA 2.0 mg/L + NAA 0.5 mg/L + KT 0.2 mg/L。     

甘肃瑞香组织培养技术研究

以野生甘肃瑞香顶芽为外植体进行组织培养实验研究。结果表明:甘肃瑞香愈伤组织诱导的培养基为MS+2,4-D3.0 mg/L+6-BA3.0 mg/L;愈伤分化培养基为MS+ZT2.0 mg/L+NAA0.5 mg/L;不定芽增殖培养基为MS+6-BA1.0 mg/L+NAA0.2 mg/L,平均增殖倍数为7.8;生根培养基为1/2MS+NAA0.5 mg/L,生根数平均为3条左右,生根率为85%以上。     

“菊花组织培养”实验选取不同部位为外植体的结果比较

以菊花带芽的茎段、节间中段及叶片为外植体进行组织培养,结果表明,在MS+6-BA 2 mg/L+NAA 0.5 mg/L的培养基中,带芽的茎段为外植体容易成活,且生长迅速,容易直接从芽生成幼苗;节间中段为外植体经过脱分化形成愈伤组织,然后再分化形成幼苗;叶片为外植体能观察到脱分化形成愈伤组织,但是再分化形成幼苗的成功率比较低。     

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.