关于兰科盆距兰属与囊唇兰属的混淆问题

回顾盆距兰属(Gastrochilus)与囊唇兰属(Saccolabium)两个混淆属的简史。它们为彼此明显不同的独立属。盆距兰属的唇瓣为半球形囊状,侧裂片不明显,中裂片甚大;蕊柱无足;花粉团具孔隙。囊唇兰属的唇瓣为圆筒状距形,侧裂片明显,中裂片很小;蕊柱有短足;花粉团实心。前者广泛分布于亚洲热带与亚热带地区;后者则只局限于印度尼西亚的爪哇与苏门答腊。因此,建议在国际命名法规中取消保留名Saccolabium以及作为其异名的废弃名Gastrochilus(1822号)。     

假烟叶唇柱苣苔——中国广西石灰岩地区苦苣苔科一新种

报道了广西石灰岩地区苦苣苔科唇柱苣苔属(Chirita Buch.-Ham.ex D.Don)1新种--假烟叶唇柱苣苔(C.pseudoheterotricha T.J.Zhou.B.Pan & W.B.Xu).该种在叶型上与烟叶唇柱苣苔(C. heterotricha Merr.)较相近,但不同在于根状茎节间长2～8 mm,叶片和叶柄两面密被腺毛,侧脉3～4条,整个花序被开展的腺毛,花萼裂片披针形,花冠裂片长圆形,花丝在中部扭曲,密被紫色腺毛.     

麻栗坡长叶兰,中国云南兰科一新杂种

报道了产自云南麻栗坡的兰科兰属一新杂种——麻栗坡长叶兰(Cymbidium×malipoense L.J.Chen,H.B.Zhou&Z.J.Liu),对该种的形态特征进行了描述。该种可能是长叶兰(Cymbidium erythraeum Lindl.)与龙州兰(C.eburneum var.longzhouense Z.J.Liu et S.C.Chen)的天然杂交种。本种与长叶兰的区别是:本种的花葶自叶腋发出;萼片和花瓣浅黄绿色,具浅紫红色的纵条纹和斑点;唇盘具黄色褶片;蕊柱浅紫红色;中裂片卵状肾形。长叶兰的萼片和花瓣绿色,有红褐色脉纹和不规则斑点;中裂片心形到剑形;唇盘密被毛。本种与龙州兰的区别是:本种萼片和花瓣浅黄绿色,具浅紫红色的纵条纹和斑点;侧裂片有紫红色条纹;蕊柱浅紫红色。龙州兰萼片和花瓣白色,外表面略带粉红色;唇瓣白色,侧裂片和中裂片具有紫红色斑点。     

中国石斛属 (兰科) 一未详知种——喉红石斛

报道了中国兰科植物一未详知种——喉红石斛Dendrobium christyanum Rchb.f.,提供了其形态描述和墨线图。它在形态上与矮石斛Dbellatulum Rolfe相似,但其唇瓣白色,唇盘中央橘红色,侧裂片和中裂片基部有黄色晕而与后者不同。这两种植物隶属石斛属黑毛组Sect Formosae。     

中越带唇兰,中国带唇兰属(兰科)一新记录种

报道了中国兰科(Orchidaceae)植物一新记录种:中越带唇兰(TainiaacuminataAveryanov),并提供形态描述及彩色图片。该种与心叶带唇兰(T. cordifolia Hook. f.)相近,不同在于萼片与花瓣均为狭披针形,唇瓣无侧裂片,阔披针形,渐尖,唇瓣边缘在中上部波状卷曲,唇盘具3条不明显的脊。     

中国石斛属(兰科)一未详知种--喉红石斛

报道了中国兰科植物一未详知种——喉红石斛Dendrobium christyaaum Rchb．f．,提供了其形态描述和墨线图。它在形态上与矮石斛D．bellatulum Rolfe相似,但其唇瓣白色,唇盘中央橘红色,侧裂片和中裂片基部有黄色晕而与后者不同。这两种植物隶属石斛属黑毛组Sect．Fonnosae。     

台闽苣苔(苦苣苔科)花部器官的形态发生

在扫描电镜下对台闽苣苔 (T. oldhamii (Hemsl.) Solereder)进行了花部器官形态发生的观察,为探索该类群的个体发育、类群间的系统发育关系和进化趋势提供依据.研究发现该属植物萼片、花冠和雄蕊发生式样均为五数花类型,它们各自来源于花原基上分化出来的萼片原基、花冠原基和雄蕊原基;花冠与雄蕊的两侧对称性与花冠上唇生长稍快和退化雄蕊原基发育迟滞相关;萼片原基的发生和发育的顺序是不一致的:萼片原基发生的式样为近轴中原基-远轴2原基-2侧原基,发育式样则为近轴中萼片-2侧萼片-远轴2萼片,花蕾时为镊合状排列.花冠裂片原基的发生和发育式样是一致的,即远轴中裂原基(下唇中裂片)-远轴2侧裂原基(下唇2侧裂片)-近轴2裂原基(上唇2裂片).花蕾期卷迭式为覆瓦状排列,从外向内:下唇中裂片-下唇2侧裂片-上唇2裂片或下唇2侧裂片-上唇2裂片-下唇中裂片.雄蕊原基与花冠裂片原基互生,前方雄蕊原基在发生上稍迟于后方雄蕊原基,后者与退化雄蕊原基几乎同时发生,但较小,并与近轴心皮(或柱头上唇)对生.将该属与玄参科(Scrophulariaceae)的地黄属( Rehmannia )、苦苣苔科(Gesneriaceae)的异叶苣苔属( Whytockia)和尖舌苣苔属(Rhynchoglossum )的花部器官比较发现,这四个属在这方面呈现出多样性和交叉.过去一直按子房室数和胎座类型划分玄参科(子房2室、中轴胎座)和苦苣苔科(子房1室、侧膜胎座)这一做法受到了质疑.     

中越带唇兰, 中国带唇兰属(兰科)一新记录

报道了中国兰科（Orchidaceae）植物一新记录种：中越带唇兰（Tainia acuminata Averyanov）,并提供形态描述及彩色图片。该种与心叶带唇兰（T.cordifolia Hook.f.）相近,不同在于萼片与花瓣均为狭披针形,唇瓣无侧裂片,阔披针形,渐尖,唇瓣边缘在中上部波状卷曲,唇盘具3条不明显的脊。     

中国陕西兰科1新种——巴山山兰

报道了发现于陕西省大巴山地区的山兰属植物新种——巴山山兰(Oreorchis bashanensis),该种与山兰(O.patens)接近,主要区别在于前者先花后叶,假鳞茎较大,叶2~3枚,叶片较大,花唇瓣爪长度占总长1/2,唇瓣侧裂片直立,褶片在唇盘中央膨大为橙红色龙骨状附属物,并突出于唇瓣之上;后者四季常绿,叶1~2枚,叶片较小,花唇瓣爪长度约为总长1/4,唇瓣侧裂片镰曲,唇盘纵褶片脊状,白色至浅黄色。凭证标本藏于陕西理工大学植物标本馆(HZTC)。     

中国兰科植物三个新记录种

报道了中国兰科植物的三个新记录种,裂唇卷瓣兰(Bulbophyllum picturatum),长柄虾脊兰(Calan-the allizettei)和绿花毛兰(Eria lanigera)。裂唇卷瓣兰的中萼片全缘前部具一粒状附属物,唇瓣基部两侧具耳。长柄虾脊兰的中裂片非常小并具三条褶片。黄花毛兰的花黄绿色,唇瓣不裂。     

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     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV