豹子花属的花粉形态研究，兼论与百合属的界限问题

本文借助光学显微镜和扫描电镜,对豹子花属Nomocharis 6种植物和百合属Lilium 4 种植物的花粉形态与外部特征作了较系统的比较研究,其结果如下： 1．豹子花属植物花粉的 萌发孔均为单沟(远极)型,根据其外壁结构及表面纹饰的特点,可分为基柱网纹型和网纹 型,结合外部形态特征推断,可能存在由基柱网纹→网纹的进化趋势。 2．百合属植物花粉 的萌发孔多为单沟(远极)型,稀为2一3孔型,然而,其中外部形态极为相近的小百合集合群与 尖被百合在花粉形态上表现出较大的差异,这一事实为研究百合科花粉的演化提供了线索。豹 子花属与百合属花粉虽在表面纹饰上存在区别,但从外部形态上,该属的一些种类与百合属极 为相近,反映出二属之间存在着较为紧密的亲缘关系。     

12种十字花科植物花粉形态研究

采用扫描电子显微镜对十字花科8属12种植物的花粉形态特征进行了观察分析.其中8种为首次报道.观察结果表明:4族8属12种十字花科植物花粉形态的一般特征为:花粉粒长球形至超长球形;极面观三裂圆形,少数四裂圆形;外壁纹饰为网状或细网状纹饰;三沟,偶四沟.12种植物的花粉可划分为5种类型:(1)花粉粒长球形,网状纹饰,三沟;(2)花粉粒超长球形,网状纹饰,三沟;(3)花粉粒长球形,细网状纹饰,三沟;(4)花粉粒超长球形,细网状纹饰,三沟;(5)花粉粒长球形,三或四沟,网状纹饰.十字花科花粉形态特征在不同族间、不同属间以及同属不同种间均没有明显规律,在十字花科分类过程中,不宜单独以花粉形态特征作为依据.     

中国蓼科萹蓄属植物花粉形态及其分类意义

利用扫描电镜研究了中国萹蓄属(Polygonum) 13种、1变种、1变型植物的花粉形态.结果表明,中国萹蓄属植物的花粉粒为长球形或超长球形,具三孔沟,外壁纹饰可分为4种类型(1)花粉粒表面具细网状纹饰;(2)花粉粒表面具颗粒纹饰;(3)花粉粒表面仅两端具颗粒纹饰,其余部分光滑;(4)花粉粒表面仅沟间区两端肩部光滑,其余部分具颗粒纹饰.根据花粉形态类型,结合该属植物的习性、叶柄基部及花柄上关节的有无、花柱和柱头的数目以及瘦果形态等特征,参照前人的研究处理意见,将中国萹蓄属植物划分为4个组,即小灌木组section Fruticulosae (Boiss.) F.Z.Li et Y.T.Hou,stat.& comb.nov.、萹蓄组section Polygonum、丝茎萹蓄组section Pseudomollia Boiss.和铁马鞭组section Plebeia Tzvel..     

中国淫羊藿属药用植物花粉特征及其分类学意义

淫羊藿属(Epimedium L.)植物多为常用药材,分类和药材鉴定较为困难。该文采用扫描电镜对中国产淫羊藿属31种药用植物花粉的形态、大小和表面纹饰等进行了比较观察。结果显示:(1)淫羊藿属植物花粉形态多为长球形,少数为球形,大小为(15.5~25.0)×(27.3~48.1)μm,极面观多为三裂圆形,具三孔沟。(2)花粉粒外壁表面纹饰有网状、条网状、条纹状等类型。(3)花粉粒外壁纹饰如网眼的形状、大小和网脊表面特征等在各物种间有一定差异。研究结果为淫羊藿属药材鉴定与植物分类提供了重要的参考。     

中国蓼科篇蓄属植物花粉形态及其分类意义

利用扫描电镜研究了中国蔚蓄属（Polygonum）13种、1变种、1变型植物的花粉形态。结果表明,中国蔚蓄属植物的花粉粒为长球形或超长球形,具三孔沟,外壁纹饰可分为4种类型：（1）花粉粒表面具细网状纹饰;（2）花粉粒表面具颗粒纹饰;（3）花粉粒表面仅两端具颗粒纹饰,其余部分光滑;（4）花粉粒表面仅沟间区两端肩部光滑,其余部分具颗粒纹饰。根据花粉形态类型,结合该属植物的习性、叶柄基部及花柄上关节的有无、花柱和柱头的数目以及瘦果形态等特征,参照前人的研究处理意见,将中国蔚蓄属植物划分为4个组,即小灌木组section Fruticulosae（Boiss．）F．Z．Liet Y．T．Hou,stat．＆comb．nov．篇蓄组section Polygonum、丝茎蔚蓄组section Pseudomollia Boiss．和铁马鞭组section Plebeia Tzvel．。     

22种假瘤蕨属植物孢子纹饰超微特征

利用扫描电镜对假瘤蕨属2系、5亚系22种植物的孢子纹饰特征进行了研究.结果显示:该属孢子为单裂缝、两侧对称,极面观为椭圆形,赤道面观为肾形.表面纹饰具有6种类型:光滑、粗糙、颗粒、棒状、疣状和瘤状纹饰以及它们之间的过渡类型.研究表明,孢子纹饰特征可以用来区分该属中的近缘种,但不能用以界定假瘤蕨属的属下分类--系和亚系.     

厚朴基原植物及其4个近缘种的花粉鉴定

采用扫描电镜对2种厚朴基原植物(厚朴Magnolia officinalis Rehd.et Wils.、凹叶厚朴M.officinalis Rehd.et Wils.var.biloba Rehd.et Wils.)及4种近缘植物(玉兰M.denudata Desr.、紫玉兰M.liliiflora Desr.、望春玉兰M.biondii Pampan.、荷花玉兰M.grandiflora L.)的花粉形态、表面纹饰和大小进行了观察研究。结果显示:(1)6种植物的花粉粒均为单粒,具远极单萌发沟,沟长,直达两端,左右对称,异极;侧面观均为舟形,两端较尖,赤道面观为椭圆形或近椭圆形,极面观均为近圆形;外壁均具小穴状或网状纹饰。(2)厚朴的小穴状纹饰小而浅,不明显;凹叶厚朴的小穴状纹饰小但较深,也不甚明显;相比之下,紫玉兰、玉兰、望春玉兰和荷花玉兰的花粉粒表面密布不规则隆起及深穴点,明显。(3)6种植物花粉粒由大至小依次为:荷花玉兰凹叶厚朴厚朴玉兰紫玉兰望春玉兰。3种不同的花粉处理方法中,自然干燥法能清晰地观察到花粉的扫描电镜特征,此方法优于戊二醛固定法和叔丁醇真空冷冻干燥法。本研究结果为厚朴中药资源的基原植物及其近缘种鉴定提供了新的证据,也为现代植物从种及亚种级水平分类提供了参考。     

云南紫金牛属3种植物花粉粒形态特征

利用光学显微镜和电子显微镜对云南紫金牛属朱砂根、柳叶紫金牛和矮地茶的花粉进行了观察.其中,柳叶紫金牛属首次报道.结果表明:3种紫金牛属植物的花粉为单粒,三角状类圆球型;异极型,两侧对称;赤道面观为三面略凹的类圆球形;极面的顶面观为类三角形,具三孔(沟),为沟孔型,萌发沟为拟沟,多合成合沟,底面观为三面围合的深洞穴状.外壁多具穴状纹饰,表面光滑无附属物.云南紫金牛属花粉粒大小、形态、萌发沟和纹饰类型都较接近,属于单一型花粉.     

中国蕨类植物孢子形态的研究Ⅲ.金星蕨科1.毛蕨属

利用扫描电镜对中国产毛蕨属51种植物孢子形态进行了研究。结果表明：该属孢子为单裂缝,两侧对称,极面观为椭圆形,赤道面观为肾形,由周壁形成表面纹饰。表面纹饰可分为3种类型：(1)周壁具流苏状的翅状纹饰,表面有突起或穿孔,有19种属于此类型;(2)鸡冠状纹饰,有11种属于此类型;(3)刺状纹饰,有10种属于此类型。另外有11种具有上述纹饰的混合纹饰,被认为是中间类型。孢子的形态特征可作为该属的分类学和孢粉学研究的资料。     

山西霍山罂粟科植物花粉形态

利用光学显微镜和扫描电子显微镜对山西霍山罂粟科白屈菜属白屈菜、紫堇属延胡索、角茴香属角茴香、秃疮花属秃疮花 4种的花粉形态进行了观察和比较研究 ,以上 4种花粉差异大。角茴香花粉粒近球形 ,具合沟 ;延胡索花粉粒长球形 ,表面纹饰较光滑 ;白屈菜花粉粒长球形或近球形 ;秃疮花花粉粒近球形。角茴香花粉表面纹饰为刺状纹和细网状纹的复合纹 ,白屈菜花粉表面纹饰为细网状纹和颗粒状纹的复合纹 ,秃疮花花粉表面纹饰为细颗粒状纹。延胡索、白屈菜、秃疮花花粉粒的萌发沟均为三沟 ,但沟的形态均不相同     

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.