李的孢粉学初步研究

为了解李的起源,应用扫描电镜对7份李(Prunus salicina L.var.cordata Y.He)、2份中国李(P.salicina Lindl.var.salicina)、1份樱桃李(P.cerasifera Ehrhart.)及3份杂种李的花粉形态进行观察和聚类分析,开展李的孢粉学研究。结果表明,这13份李属植物的花粉具条纹-穴状或脑纹-穴状纹饰,花粉形状均为长球形或超长球形,极面观为三裂圆形,具3条萌发沟,萌发沟以等间距环状分布,属N3P4C5类型。李的P/E(1.82~2.02)、花粉大小(823.70~970.42μm2)介于供试的其他6份李属植物之间,但其穿孔密度(0.520~1.141μm–2)除早圆油和早熟油外均远大于其他6份李材料;李花粉外壁具条脊,表面均形成大小、疏密不等的穿孔,且在条脊隆起、脊沟深窄等方面表现出了丰富的多样性,其中油早熟品系和晚熟品系的花粉纹饰、穿孔密度等还表现出了2种特征,因此,李的孢粉学特征可作为分类鉴定的一个重要依据。在遗传距离6.19水平上,13份李属植物可以分为3个类群,每个类群中均有李分布,李与李属间具有较近的亲缘关系。综合李花粉形态特征和聚类分析结果,推测李具起源于李属杂交后代的可能。     

黑龙江省抗寒李资源花粉形态的比较观察

对31个寒地李资源进行了电镜扫描,在测量极轴、赤道轴,条脊宽、穿孔径、穿孔频率后,分析出31个李品种花粉粒大小属于小至中等,31个李品种大多为长球形（比值2～1.14）,个别品种牛心李、长李17号、吉林六号为超长球形（比值>2）, 均有3条沿极轴走向的等间距的发芽沟,发芽沟的有开张、半开张、不开张3种。31个李品种的外壁纹饰可以分为七种类型,大多数李品种的纹饰是条脊平行或分枝多穿孔纹饰,云状纹饰品种少为矮甜李、龙园秋李,脑纹状纹饰只有延吉李。根据极轴、赤道轴、条脊宽、穿孔径、穿孔频率5项指标,采用最远距离法对31个李品种进行聚类分析,牛心李与其它30个李品种亲缘较远。     

横断山区植物的花粉形态及生态意义（英文）

应用光学显微镜和扫描电子显微镜对中国西南部横断山区夏季开花的27科43属46种2变种植物的花粉形态进行了观察和研究,并对花粉形态进行了细致的描述。结果表明,花粉类型以近长球形—长球形和长球形为主,分别为27.1%和25%,还有少量的为球形,近球形—近长球形,近扁球形和四合花粉。萌发孔以3孔沟为主,占43.8%,还有3沟,散孔,多沟,三拟孔沟,6-沟,单沟等类型。外壁纹饰以细网状为主占50%,还有粗网状,细颗粒状,光滑,刺状纹饰等。这些物种的孢粉学特征为第四纪地层孢粉研究提供了现代孢粉学依据。此外在花粉形态性状基础上,通过SPSS软件聚类分析,对部分同科物种间的鉴定特征进行了讨论分析,并根据植物的生态学特性讨论了它们的生态环境指示意义。     

中国鸡矢藤属花粉形态

用扫描电子显微镜对中国鸡矢藤属(Paederia L.)6种1变种植物的花粉进行观察。结果表明:鸡矢藤属植物的花粉均为单粒,辐射对称,小型或中型,极面观3-裂圆形至钝三角形,赤道面观呈长圆球形或近长球形,具3个萌发沟,无内萌发孔。外壁纹饰网状、细网状或穿孔状,孔边缘具小刺状突起或无。臭鸡矢藤(P.foetida)和白毛鸡矢藤(P.pertomentosa)具有花粉二型现象,其中白毛鸡矢藤(P.pertomentosa)是首次报道。花粉二型现象与花柱二型现象可能没有直接的关联性,与前人的观点一致。推测鸡矢藤属外壁纹饰的可能演化趋势为:穿孔、网状、细网状→粗网状;网眼内无棒状突起→网眼内有棒状突起。鸡矢藤属花粉的外壁纹饰变化较大,且无内萌发孔,是茜草科花粉过渡类型的特征。     

基于花粉形态数量分类的核果类系统关系研究

运用扫描电子显微镜(SEM)观察了李属、杏属、樱桃属和桃属的花粉形态,观察结果表明:核果类果树的花粉均为近扁球形,等极,辐射对称,极面观为三角形或钝三角形,赤面观均为椭圆形,花粉粒大小在各属间差异明显。核果类果树花粉属N3P4C5类型,3条孔沟沿极轴方向在赤道面上等间距环状分布,内孔位于沟的中央,完全独立于外壁,孔盖覆不规则的拟网状或脑纹状纹饰。供试核果类果树花粉的表面纹饰由平行条纹或不规则条脊及散落于条脊间的穿孔组成,各属间条脊的排列方式、宽窄、脊洼深浅及穿孔有无等性状上存在明显差异。根据花粉大小、表面纹饰及覆盖层穿孔等的一般演化规律,推测核果类果树由低到高的演化顺序为李属→杏属→樱桃属→桃属,并在聚类分析的基础上对属间亲缘关系进行了探讨,旨在为核果类系统关系的研究提供孢粉证据。     

色季拉山10种报春花属植物花粉形态及其分类学意义

采用扫描电镜法,观察和比较了西藏色季拉山10种报春花的花粉形态特征,同时进行聚类分析,以期为该属植物分类提供孢粉学证据,并进一步为西藏报春花属植物杂交育种及种质资源的利用提供参考。结果表明：(1)供试10种报春花属植物的花粉形状为扁球形、近球形,其中,工布报春(Primula kongboensis)的花粉粒最小,暗紫脆蒴报春(P.calderiana)的花粉粒最大,西藏报春(P.tibetica)为多沟型花粉,其余报春花的花粉一般具3孔沟,大部分孔沟在极区汇合形成复合沟。(2)花粉外壁纹饰大多为穴状或网状,其中,中甸灯台报春(P.chungensis)和西藏报春为网状纹饰中的粗网状类型。(3)虽然基于花粉形态的聚类分析与植物学分类表现出一定的一致性,但粉报春组的西藏报春和工布报春则由于在孢粉学特征上具有明显差异,因此保持了相对较远的亲缘关系。该研究初步认为,色季拉山10种报春花粉形态存在种间差异,研究结果可为植物分类提供一定的参考依据。然而,在进行分类时,仍然需要结合形态学特征、分子生物学等方面综合考虑。     

泽泻科的花粉形态研究

本文对泽泻科11属27种代表植物的花粉进行了光学显微镜、扫描电镜和透射电镜观察。在系统描述了该科及各属植物花粉形态的基础上,将泽泻科植物的花粉划分为3种类型,即少果泽苔草型、慈菇型和泽泻型。根据花粉形态特征的比较,并依据泽泻科植物祖先类群的花粉具有船形、具单沟萌发孔、花粉外壁具明显的刺状纹饰、覆盖层完整无通道等特征,作者认为泽泻科植物花粉形态的如下演化趋势是明显的：由船形演化为卵球形、球形和多面体球形;由单沟萌发孔经过一无孔的中间类型演化为散孔类型;孔膜由光滑演化为具颗粒和小刺;萌发孔不内陷进化到内陷;花粉粒外壁的刺状纹饰逐渐过渡为颗粒状纹饰或者消失,以及覆盖层由无通道到具细通道和通道。     

中国菟丝子属植物花粉的扫描电镜观察

本文作者用扫描电镜(SEM)对国产菟丝子属(Cuscuta L.)10种植物的花粉形态进行了观察。具3沟萌发孔的花粉为本属基本类型。根据萌发孔的数目,外壁纹饰等特征,该属花粉可划分为三个类型:(1)具3沟,外壁具穿孔,表面散生小刺状突起;(2)具3—5沟,外壁具网状纹饰,网脊上散生小刺状突起;(3)具3—6沟,外壁具小刺状突起,穿孔偶见。本文观察结果与刘炳仑等曾报道过光学显微镜(LM)下的结果不完全一致。最后,对菟丝子属的花粉形态的演化趋势以及属内亚属间关系进行了讨论。     

中国钩藤属9种植物的花粉形态

利用光学显微镜和扫描电镜对中国钩藤属(Uncaria Schreb)9种植物的花粉形态进行了观察.结果表明,钩藤属植物的花粉为单粒,小型,辐射对称,赤道面观圆球形至近长球形,极面观3-裂圆形,具3孔沟,萌发沟裂缝状,长达两极.萌发沟中央有"内壁加厚突出"结构.外壁具条纹至细网纹饰,表面光滑无附属物.钩藤属花粉大小、形状、萌发沟和纹饰类型都较接近,属于单一型花粉.钩藤属植物的花粉形态特征是茜草科(Rubiaceae)中较为原始的类型.     

国产蔷薇科李亚科的花粉形态

本文报道了国产李亚科（Ｐｒｕｎｏｉｄｅａｅ）１０属１１种植物花粉形态。花粉近球形至长球形,极轴２０００～４４１２μｍ,赤道轴１７８５～３６９５μｍ。极面观三裂圆形,赤道面观椭圆形至圆形。具三孔沟,内孔常为长方形。沟较长,两端较窄。但在Ｓｉｎｏｐｌａｇｉｏｓｐｅｒｍｕｍｕｎｉｆｌｏｒａ中除了３孔沟外,还有周孔沟。花粉外壁明显分化为覆盖层和柱状层,在光学显微镜下表面常模糊,扫描电镜下外壁纹饰均为条纹状。孢粉学结合形态学和细胞学证据说明本亚科为一单系发生的类群。Ｐｒｉｎｓｅｐｉａｕｔｉｌｉｓ和Ｓｉｎｏｐｌａｇｉｏｓｐｅｒｍｕｍｕｎｉｆｌｏｒａ（Ｐｒｉｎｓｅｐｉａｕｎｉｆｌｏｒａ）这两个种在花粉特征和外壁纹饰上差异很大,从而支持将Ｐｒｉｎｓｅｐｉａ和Ｓｉｎｏｐｌａｇｉｏｓｐｅｒｍｕｍ分别处理为两个属但不支持将广义的Ｐｒｉｎｃｅｐｉａ（含Ｐｒｉｎｃｅｐｉａ和Ｓｉｎｏｐｌａｇｉｏｓｐｅｒｍｕｍ）独立为亚科。此外,由于Ｅｘｏｃｈｏｒｄａ的外壁纹饰同Ｐｒｕｎｏｉｄｅａｅ中较原始的类群（如Ｌａｕｒｏｃｅｒａｓｕｓ）相近,结合细胞学和形态学证据,支持将Ｅｘｏｃｈｏｒｄａ移置至Ｐｒｕｎｏｉｄｅａｅ之下     

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.