棕头鸦雀分类问题商榷

棕头鸦雀的分类有过几次较为系统的整理研究。因其飞羽外缘有栗红色与褐色两种类型,前者又可分为红胸、灰胸两类群,故在分类上各学者持有不同意见。或将其分为3个种,或归并为1种。本文依据作者工作结果,从地理分布、形态及骨骼性状进行分析研究,认为棕头鸦雀具栗红翅缘的红胸、灰胸两类群在中国西南地区的云、贵、川三省的亚种分布接触地带彼此混交并有居间个体,不应独立为两个不同种。栗红翅缘褐色翅缘两大类群尚未发现重叠分布,形态明显间断,一直未见有中间类型。两大类群在头骨的泪骨突起和方骨形态上有明显差异,建议将它们分为Paradoxornis webbianus和paradoxornis brunneus。前者再分为红胸、灰胸两亚种组。对少数有争议的亚种也提出了处理意见。     

中国鹅观草属的分类研究

本文对中国鹅观草属Roegneria进行了分类修订,提出了一个新的分类系统。新系统包括19个新组合或新等级,并按照颖分组、芒分系的原则确认了中国该属植物4组、18系、79种、22变种,其中包括7新系、5新种和1新变种。此外,一些类群的省级分布新记录也在本文作了报道。     

国产赖草属的分类修订

通过标本研究和野外考察,对中国赖草属（Leymus Hochst.）进行了分类修订。结果在中国共确认了3组、33种、7变种赖草属植物,其中多穗组包含4种,少穗组包含24种、7变种,单穗组包含5种,新报道的3个种和新修订的4个类群（即3个新组合和1个新名称）皆隶于少穗组。同时对赖草属的研究简史、属的形态特征和一些类群的地理分布也分别作了简要介绍。     

中国柳莺属分类现状

柳莺属Phylloscopus一直是中国鸟类分类学中问题最多,研究最不完善的类群。在上世纪末的10年中,新增加了12种柳莺,包括新发现的3种和亚种被提升到种地位的9种。本文回顾和介绍了我国柳莺属分类研究概况,包括四川柳莺P.sichuanensis,海南柳莺P.hainanus和峨眉柳莺P.emeiensis3个新发现种。黄腰柳莺青藏亚种P.proregulus chloronotus和甘肃亚种P.p.kansuensis,黄腹柳莺P.affinis subaffinis亚种。黄腰柳莺青藏亚种P.proregulus chloronotus和甘肃亚种和P.c.sindianus亚种,黄眉柳莺P.inormatus humei亚种等的分类地位已由亚种升为种,但黑眉柳莺P.ricketti goodsoni亚种分类地位仍存在着争议,最后提出了目前我国柳莺属分类上尚存在的一些问题。     

木槿的发育可塑性及种下分类研究

对紫花单瓣木槿、紫花重瓣木槿和牡丹木槿在叶和花部性状上的发育可塑性研究表明,三个种下类群,特别是紫花单瓣木槿和牡丹木槿的叶片性状具有很大的发育可塑性,但花部性状的发育可塑性则相对很小,暗示着花部性状较叶片性状具有更大的分类价值。通过种下类群间表型性状的比较,发现牡丹木槿在叶缘、叶柄长度、花色、花冠直径、花梗长度、果实长宽比等性状上都与其它两个类群存在显著差异,从而建议将牡丹木槿确立为亚种(H. syriacus Linn. subsp. paeoniflorus (Gagnep.)G. R. Shi)     

重订羌活属的分类

在野外实地观察和标本整理的基础上,检查了羌活属各个分类群的分类问题,考证了它们的名称。通过性状分析,主要以小总苞片的形状及其相关特征作为属下分类的依据,将卵叶羌活N．oviforme 改隶于宽叶羌活之下作为亚种处理,支持张盍曾在1975年将 N.franchetii 与N.forbesii合并为1种。如此,该属共5种,其中1种含1亚种。描述了两个新组,对属的特征和地理分布作了补充。近年该属新增加2种,因此分种检索表也作了相应的修改。     

重订藤山柳属的分类——续谈植物分类学工作方法

藤山柳属Clematoclethra(猕猴桃科)是中国特有属之一。本文作者研究了该属植物的外部形态,统计了473张标本,结合地理分布,得出本属是一个单种属,并且是一个多型种的结论。此种分为4个亚种。这与中国植物志的作者将本属分为20种和4变种不同。 本文作者虽强调标本室分类是生物系统学研究的基础,是必不可少的一步,但这种分类,其方法上必须根据大量标本,从研究性状变异开始,然后确定各分类群的划分和等级,最后才根据植物命名法规的模式方法,给予它们正确名称。作者还根据本属的姊妹群猕猴桃属和它们的外类群水东哥属的地理分布,推断本属是一个新特有属。     

尖棱甲螨科分类研究进展及区系分析

尖棱甲螨科Ceratozetidae隶属于蛛形纲Arachnida甲螨亚目Oribatida尖棱甲螨总科Ceratozetoidea,是种类较多、分布较广的高等甲螨类群之一,目前全世界共记载24属271种,中国仅7属11种。本文概述了尖棱甲螨科的分类研究现状,回顾了其230多年的分类研究历史,并介绍了研究该类群的代表人物及其成就。同时也介绍了世界及中国尖棱甲螨科各属种的地理分布状况,指出了目前对该类群的研究不均衡、基础薄弱等主要问题,建议当前和今后较长时间内应以种类收集和描述为主,加强国际交流与合作,推动该类群研究的发展。     

中国树鼩的分类研究

本文对中国南部和西南部树鼩的分类问题进行了整理。讨论了中南半岛树鼩的种级分类,提出了中南半岛北部地区的Tupaia belangeri及其近似亚种应恢复其种级分类地位;T.belangeri yunalis,T.belangeri tonquinia和T.belangeri modesta应是3个有效亚种;记述了分布于中国南部和西南部的树鼩为6个亚种,其中有两个新亚种T.belangeri gongshanensis subsp.nov.(云南高黎贡山地区)T.belangeri yaoshanensis subsp.nov.(广西瑶山)。     

中国鹅鸡草属的分类研究

本对中国鹅观草属Ｒｏｅｇｎｅｒｉａ进行分类修订,提出了一个新的分类系统。新系统包括１９个新组合成新等级,并按照颖分组、荒分系的原则确认了中国该属植物４组、１８系、７９种、２２变种,其中包括７新系、５新种和１新变种。此外,一些类群的省级分布新记录在本作了报道。     

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