中国大帽藓科（Encalyptaceae,Musci）植物分类和分布的研究

在研究文献和标本的基础上,简要回顾了中国大帽藓科（Encalyptaceae）植物的研究进展,对中国大帽藓科植物的分类和分布进行了整理研究。现知中国仅分布大帽藓属（Encalypta Hedw.)1属10种。本研究按照吴征镒^[1]关于划分中国种子植物属的分布区类型的划分方法,将中国大帽藓属划分为6个分布区类型和3个变型,其中的拟烟杆大帽藓（Encalypta buxbaumioidea)、中华大帽藓（E.sinica）和天山大帽藓（E.tianschanica）等3种为中国特有分布类型。文中概括了每个种的识别特征、生境和分布区类型,并以拟烟杆大帽藓、中华大帽藓和天山大帽藓绘图描述。根据标本编制了中国大帽藓属植物分种检索表。     

国产四种绢藓属植物的核型研究

国产苔藓植物的核型研究,目前尚未见到任何报道。本文对中国产绢藓属4种植物进行了核型研究。观察了配子体有丝分裂中期的染色体和异染色体。4种植物的染色体数目均为11。钝叶绢藓(E．obtusatus),密叶绢藓(E．compressus),东亚绢藓(E．okamurae),的核型公式为K(n)=11＝2V(H)+2J+6(4v+2i)+m(h),陕西绢藓(E.giraldii)为K(n)＝11＝2V(H)+V+2J+5(3v+2i)+m(h)．4种植物的核型均为首次报道。     

密叶绢藓一新变种

报导了密叶绢藓一新变种,即密叶绢藓小孢变种Entodon compressus C.Muell.var.parvisporus X.S.Wen et Z.T.Zhao.     

黎平太平山自然保护区树附生藓类植物多样性

为探讨贵州亚热带常绿阔叶林树附生藓类植物多样性,以黎平太平山自然保护区为例,对该区树附生藓类植物进行调查研究,共获得432份标本。鉴定及分析结果显示:该区有树附生藓类植物31科89属197种,较之前人对该区苔藓植物的调查工作,新增3个科32个属128个种;优势科包含蔓藓科(Meteoriaceae)、平藓科(Neckeraceae)、青藓科(Brachytheciaceae)、毛锦藓科(Pylaisiadelphaceae)、灰藓科(Hypnaceae)等5个科,优势属有凤尾藓属(Fissidens)、匐灯藓属(Plagiomnium)、青藓属(Brachythecium)、绢藓属(Entodon)、灰藓属(Hypnum)等5个属;树附生藓类植物区系地理成分组成复杂,划分为12种分布类型,东亚分布成分最为丰富,有76种,占总种数的39.79%,热带亚洲分布成分有26种,与其他大洲热带成分相联系的种类达33种,占比17.28%,中国特有成分有16种,占比8.38%;生活型可划分为6种,交织型占主体地位,有88种,占总种数的44.67%。     

云南省柳叶藓科植物新记录

在研究标本和文献的基础上,报道了云南省柳叶藓科植物的11个新分布记录种和3个变种,包括1个中国新分布记录种细肋镰刀藓(Drepnocaldus tenuinervis Kop.),并对它们的生境和地理分布作了初步讨论．     

北京东灵山苔藓植物区系研究

在野外调查和采集标本的基础上,对北京东灵山苔藓植物区系成分及特点进行研究。结果显示,该地区共有苔藓植物27科64属150种(含2变种),其中32种为北京苔藓植物新记录。优势科为青藓科(Brachytheciaceae)、丛藓科(Pottiaceae)、灰藓科(Hypnaceae)、真藓科(Bryaceae)和绢藓科(Entodontaceae)5科;优势属为青藓属(Brachythecium)、绢藓属(Entodon)、紫萼藓属(Grimmia)、真藓属(Bryum)、金灰藓属(Pylaisia)、凤尾藓属(Fissidens)、美喙藓属(Eurhynchium)和毛口藓属(Trichostomum)8属。区系分析表明,东灵山苔藓植物区系地理成分以北温带成分为主(占36.7%)、东亚成分次之(占18.0%)。通过与我国15个地区苔藓植物区系谱主成分分析发现,东灵山苔藓植物区系成分与雾灵山、小五台山与贺兰山相近,与云蒙山最为接近。     

中国东北六种藓类植物的细胞学观察

本文对我国东北产6种藓类的孢子母细胞减数分裂中期I的染色体数进行了报道。结果如下： 羽枝青藓Brachythecium plumosum （Hedw．)B．S．G．,n=15;钝叶绢藓Entodon obtusatus(Mitt) Jaeg．,n=11;东亚绢藓E．okamurae Mitt,n=11;丛本藓Anoctangium aestivum(Hedw．)Mitt．, n＝13;真藓Bryum argenteum Hedw．,n=10;尖叶美喙藓Eurhynchium eustegium(Besch．)Dix.,n=20+2m,其中前三种为首次报道。     

中国藓类植物新记录种——莫氏疣壶藓

报道了采自中国广西乐业县大石围天坑群洞穴藓类植物中国新记录种——莫氏疣壶藓Gymnostomiella monodii P.de la Varde(丛藓科Pottiaceae)。该种的主要识别特征是:植物体细小;叶中上部边缘多具齿突,先端具短锐尖;叶中上部细胞一般具0~1(~2)个乳突状疣;芽胞棒槌状。中国目前分布的疣壶藓属植物共3种和2变种,并提供分种检索表。     

毛尖连轴藓及其近缘种的比较形态学研究

连轴藓属(Schistidium Brid.)的毛尖连轴藓(S.lancifolium)、圆蒴连轴藓(S.apocarpum)和粗疣连轴藓(S.strictum)在内蒙古贺兰山和黑龙江五大连池均有分布,它们的形态特征较为相似,极易混淆,因此对其分类鉴定较困难。本文利用光学显微镜并结合Blom的形态学和Ignatova的分子系统学分类观点,对采自两个地区的3种连轴藓属植物标本进行了分类研究,并对它们的形态特征进行了详细描述。其形态特征是:圆蒴连轴藓叶中肋背部无疣或上部具分散低疣、叶缘上部微具钝齿,毛尖平滑或具小齿;毛尖连轴藓叶中肋背面中部以上具高疣、叶缘中上部具强烈不规则的齿或锯齿,毛尖具强烈刺状齿;粗疣连轴藓除叶中肋背部具疣外,叶片细胞也具疣。根据以上特征可以区别并确认这3个种是各自独立的种。在此基础上,根据Blom的分类观点,并参照相关文献编制了中国连轴藓属11个种的分种检索表。本研究进一步确认了毛尖连轴藓在中国的地理分布,丰富了中国连轴藓属的研究资料。     

滦河上游地区藓类植物区系的初步研究

于2001~2005年在滦河上游地区共采集藓类植物标本1 810份,并对标本进行了整理鉴定.分析结果表明,滦河上游地区共有藓类植物27科75属175种1亚种12变种2变型,分别占全国藓类植物科、属、种(含种下分类单位)总数的41.54%、18.16%和7.74%.其中,河北省藓类植物新纪录6种1变种.该地区的优势科为丛藓科、柳叶藓科等6科,优势属为真藓属、青藓属等11属.该地区藓类植物可划分为10种区系成分,北温带成分居各种区系成分的首位,占该区系总种数的64.42%,东亚成分次之,占13.50%.该区系中温带性质的的种共计158种,占整个区系总种数的83.16%,而热带性质的种仅5种,显示了该地区藓类区系显著的温带性质.     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various