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.     

中国紫金牛属圆齿组花粉形态研究及其分类学意义

利用扫描电子显微镜对紫金牛属圆齿组20种1变种植物的花粉形态进行了研究,并比较分析了腋序组2种及锯齿组1种的花粉。经观察花粉为近球形或近扁球形,具3孔沟,除锯齿组的月月红外,其余种均形成合沟。外壁纹饰可分为四类:穴网状、细网状、皱波状及细颗粒状(带刺突)。结果显示,花粉形态特征可作为属下分组及组下分类处理的依据。     

红树(Rhizophora a piculata Bl.)的花粉形态与多态现象

通过光学显微镜(LM)和扫描电子显微镜(SEM)观察表明,红树(Rhizophora apiculata)花粉粒赤道面的形状为球形-近球形,极面观为圆三角形,偶见圆四方形,3-4孔沟,具有连续的环赤道内孔,花粉外壁的典型纹饰为细网状-皱纹状(microreticulate-rugulate)。作者首次报道红树花粉的多态现象,其花粉外壁纹饰和萌发孔数量存在显著的变异,SEM观察到花粉外壁纹饰的变异主要是孔状(perforate)、皱纹状(rugulate)和穴状(foveolate)等类型,LM观察发现4个萌发孔的花粉变异类型。花粉形态的观察与描述为化石花粉的鉴别提供了不可或缺的对比依据。研究红树的花粉形态和发现多态现象有助于了解红树科红树属的花粉外壁演化。花粉的多态现象表明单个花粉形态特征并不能完全代表种的特征。花粉的分类也应该充分考虑花粉性状的间断和连续性,以期正确认识花粉性状在种群内的变异和变异式样,达到客观认识和正确划分植物种下等级的目的。花粉的多态现象为化石花粉的种类鉴定增加了新的参考信息,作者也讨论了花粉多态现象在植物系统演化和古生态学等研究中的可能价值与意义。     

旌节花科及其相关类群花粉形态的研究

对旌节花科及其相关类群五桠果科、猕猴桃科、水东哥科、金莲木科、省沽油科和山茶科等7科19属37种花粉进行了光镜(LM)和扫描电镜(SEM)的观察和比较。其中有些种类是第一次观察和报道。研究表明,上述各科花粉多为近球形至球形少数近扁球形或近长球形。极面观三裂圆形或近三裂圆形。直径20-30(-35)μm,但厚皮香亚科和省沽油科银鹊树属Tapiscia的花粉特别小,仅12.5-20μm。3孔沟罕有3沟或4孔沟。外萌发孔(沟)相对地较长而宽,内孔多娄较发达花粉外壁纹饰变化大从模糊而粗糙的细突韦到皱波状纹饰,细孔状纹饰蜂巢状-穴状纹饰穴-网状纹饰网状纹饰和颗粒状纹饰等。     

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。     

红树（Rhizophora apiculata B1．）的花粉形态与多态现象

通过光学显微镜（LM）和扫描电子显微镜（SEM）观察表明,红树（Rhizophora a piculata）花粉粒赤道面的形状为球形-近球形,极面观为圆三角形,偶见圆四方形,3-4孔沟,具有连续的环赤道内孔,花粉外壁的典型纹饰为细网状一皱纹状（microreticulate-rugulate）。作者首次报道红树花粉的多态现象,其花粉外壁纹饰和萌发孔数量存在显著的变异,SEM观察到花粉外壁纹饰的变异主要是孔状（perforate）、皱纹状（rugulate）和穴状（foveolate）等类型,LM观察发现4个萌发孔的花粉变异类型。花粉形态的观察与描述为化石花粉的鉴别提供了不可或缺的对比依据。研究红树的花粉形态和发现多态现象有助于了解红树科红树属的花粉外壁演化。花粉的多态现象表明单个花粉形态特征并不能完全代表种的特征。花粉的分类也应该充分考虑花粉性状的间断和连续性,以期正确认识花粉性状在种群内的变异和变异式样,达到客观认识和正确划分植物种下等级的目的。花粉的多态现象为化石花粉的种类鉴定增加了新的参考信息,作者也讨论了花粉多态现象在植物系统演化和古生态学等研究中的可能价值与意义。     

国产爵床科芦莉花族植物的花粉形态

报道了国产爵床科Acanthaceae芦莉花族Ruellieae芦莉花亚族Ruelliinae 2属7种、假杜鹃亚族Barlerinae 1属3种和马蓝亚族Strobilanthinae 16属34种植物扫描电镜下的花粉形态.芦莉花亚族的地皮消属Pararuellia和喜花草属Eranthemum的花粉均为圆球形,具3孔或3孔沟,外壁为不同的网状结构; 假杜鹃亚族的假杜鹃属Barleria的花粉为长球形,具3孔沟,外壁亦为网状结构;马蓝亚族植物(包含广义的马蓝属Strobilanthes s.l.)花粉形态多样,结构复杂.依据花粉萌发孔和外壁纹饰特征,可将马蓝亚族16属植物和上述两亚族3属植物的花粉形态归纳成3大类型: 1. 具3孔类型.其中又有(1)外壁具网状纹饰者,见于地皮消属; (2)外壁具芽胞状纹饰者,见于黄猄草属Championella; (3)外壁具刺状(棒状)纹饰者,见于南一笼鸡属Paragutzlaffia、叉花草属Diflugossa和假蓝属Pteroptychia.2. 具3孔沟及具3孔沟与假沟类型(肋条带型).其中又有(1)具3孔沟和网状纹饰者,见于喜花草属和假杜鹃属; (2)具刺状(棒状)纹饰者,见于南一笼鸡属、叉花草属和假蓝属; (3)具3孔沟与假沟,外壁纹饰具节隔、肋条带状或网状,网眼纵向排列成行,网眼内有细网纹者,见于耳叶马蓝属Perilepta、马蓝属Pteracanthus(大部分)、金足草属Goldfussia、紫云菜属Strobilanthes(部分)和合页草属Sympagis; (4)具3孔沟与假沟类型,肋条带状,但不具节隔,外壁纹饰网状,网眼不成行或不明显纵向排列,网内无细网纹者,见于尖蕊花属Aechmanthera、板蓝属Baphicacanthus、马蓝属(部分)和糯米香属Semnostachya; (5)具双脊及细网状纹饰者,见于环毛紫云菜Strobilanthes cycla.3. 具(4-)5孔沟及假沟类型(肋条带型),外壁具网状或拟网状纹饰,见于腺背蓝属Adenacanthus.另外兰嵌马蓝属Parachampionella、山一笼鸡属Gutzlaffia和肖笼鸡属Tarphochlamys的花粉有无萌发孔尚不清楚,有待进一步研究.综上所述,芦莉花族植物的花粉形态具有较高的多样性,是重要的分类性状.利用花粉形态特征能较好地区分高级分类群如亚科、族以及亚族,有时也有助于阐明类群之间的相互关系,甚至也能用于区分属、种和阐明其关系.     

我国椴树科花粉形态的研究

本文对分布于我国的椴树科(Tiliaceae)9属44种植物的花粉形态进行了光学显微镜 的系统观察,并对其中10种花粉的外壁细微结构进行了扫描电镜观察。本科花粉为长球形、 扁球形和球形,萌发孔为长3孔沟、短3孔沟和3(一4)孔三种类型,外壁主要为网状纹饰,个 别属为刺状纹饰。根据花粉资料,本文还探讨了该科植物分类中的某些问题。     

中国无患子科的花粉形态及其系统学意义

利用扫描电镜对国产无患子科(狭义,Sapindaceae)23属30种1变种植物的花粉形态进行了观察。结果显示,该科花粉粒多为扁球形,部分为长球形,少数为球形或近球形,极面观多为三角形;从花粉萌发孔类型看,大多数种类具三沟孔,有的形成合沟,少数仅具三孔而无沟;从花粉外壁纹饰看,多数花粉外壁具网状或条纹状雕纹,少数花粉的外壁具刺状或颗粒状纹饰。花粉形态特征支持文冠果亚科(Xanthoceroideae)以及广义鳞花木属(Lepisanthes)概念,并支持仍将茶条木属(Delavaya)置于车桑子亚科(Dodonaeoideae)。观察发现黄梨木(Boniodendron minus)与栾树属(Koelreuteria),龙眼属(Dimocarpus)、荔枝属(Litchi)与韶子属(Nephelium)从花粉形态上表现出较近的亲缘关系。基于花粉形态特征编制了国产无患子科分属检索表。     

亚洲茜草科粗叶木属及其相关属植物花粉形态研究

利用光学显微镜和扫描电镜研究了茜草科粗叶木属Lasianthus 16种2亚种、1变种及相关的5属5种的花粉形态。粗叶木属的花粉属于广孢型, 单粒。一般中等大小, 绝大多数为圆球形, 少数为近长球形或长球形。花粉形态特征, 特别是在萌发孔和外壁纹饰上表现出多样化。根据孔沟的数目或是否具有内孔, 可以将萌发孔分为(3-)4-(-5)孔沟和3孔。在所观察的这些种中, 萌发孔以3-4孔沟为主要类型, 比例为62.4%。外壁纹饰可分为细网状、粗网状和穴状。有部分种的花粉极面有穴状纹饰, 其余均为网状纹饰。网眼一般椭圆形、近圆形、三角形或者不规则形。少数外壁纹饰网脊上有颗粒状雕纹或模糊的颗粒, 网脊轮廓线呈波浪形, 一般凸出且平滑。大部分种的花粉具有沟膜, 沟膜上具有瘤状突起或小颗粒状, 沟边缘一般较平滑, 或粗糙, 有的种具有沟桥。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).