山茶属植物的进化与分布

山茶属Camellia植物在其进化过程中,以雄蕊不定数、在某些类群中存在心皮离生至合生的中间过渡,认为是山茶科中较原始的一属,分布于亚洲东部和东南部,中国长江以南广袤的亚热带地区是该属的现代分布中心,中南半岛和我国云南、广西南部的热带地区种类虽少,却集中了本属原始或较原始的类群和种类。本属演化上的近缘属或姐妹群——核果茶属Pyrenaria（包括石笔术属Tutcheria）分布区大致与本属相似,其原始（子房5室,心皮先端多少分离,花柱离生）的种类也分布于此,它们可能同出于一个心皮离生的古老祖先,即生长于亚洲古热带森林环境中的类似千五桠果属（Dillenia）的原始山茶科植物,上述地区是该属的早期分化中心和起源地,大约在白垩纪特提斯海（古地中海）东岸的劳亚古陆和冈瓦纳古陆接触地带由原始五桠果类植物演化而来。山茶属植物自热带亚洲起源和分化发生后,向四周辐射状扩展,在亚洲大陆,类群和种类明显表现出由南向北、从热带向亚热带分化和替代的规律。在漫长的进化过程中,经历第三纪以来地史和古气候的变迁,分化发展为具花梗和花梗强烈缩短变无便的两个演化枝,分道扬镳平行发展,两枝在演化上相似地表现出雌、雄蕊数目的减少及合生水平的提高,本属最进化的类群是分布区南界的管蕊茶组 Sect．Calpandria和广布我国亚热带林下的连蕊茶组Sect．Theopsis,前一组花丝全部合生成肉质管,后一组雌、雄蕊高度合生,果通常1室发育,中轴退化。晚第三纪以来,古气候的变迂和亚洲山体的隆升,山茶组 Sect.Camellia,油茶组Sect．Paracamellia以及连蕊茶组 Sect．Theopsis在新的环境中产生进一步分化和自然杂交,出现了一些多倍体种群,细胞地理学研究表明,自中南半岛向北呈现出核型由对称到极不对称、染色体从二倍体到多倍体的变异系列,从而对山茶属中演化与分布的一致性提供了证据。     

中国珊瑚菌一新记录属——扁枝瑚菌属

报道了中国热带珊瑚菌类的一新纪录属——扁枝瑚菌属Scytinopogon。目前该属在我国仅在云南的西双版纳采到两种,即扁枝瑚菌S.pallescen和刺孢扁枝瑚菌S.echinosporus。文中对这两个种进行了描述,并附有插图。研究标本保存于中国科学院昆明植物研究所隐花植物标本室(HKAS)。     

中国珊瑚菌一新记录属——扁枝瑚菌属

报道了中国热带珊瑚菌类的一新纪录属--扁枝瑚菌属Scytinopogon.目前该属在我国仅在云南的西双版纳采到两种,即扁枝瑚菌S.pallescen和刺孢扁枝瑚菌S.echinosporus.文中对这两个种进行了描述,并附有插图.研究标本保存于中国科学院昆明植物研究所隐花植物标本室(HKAS).     

薏苡属的遗传变异性及核型演化

在广泛收集我国薏苡（ＣｅｒｘＬ．）种质资源,进行田间栽培,杂交试验和细胞学观察的基础上,讨论薏苡属植物的遗传多样性、地理分布及种类划分,在原１种２变种的分类基础上,把我国的薏苡属植物划分为３种４变种。根据这些种类的１８个栽培及野生类型的染色体核型演化散点图并结合总苞性状,探讨了该属可能的系统演化关系。     

基于分子系统学的可疑瑟姬小蜂分类修订及姬小蜂亚科盾纵沟的演化分析

姬小蜂为寄生蜂的演化研究提供了很好的材料。在姬小蜂分类中,盾纵沟是一个重要性状, 曾被用来区分亚科、族、属及种。非同源性相似形态特征的存在使得物种准确鉴定存在困难。从盾纵沟形状上,可疑瑟姬小蜂Cirrospilus ambiguu 和双斑潜蝇姬小蜂Diglyphus bimaculatus应介于瑟姬小蜂属Cirrospilus 和潜蝇姬小蜂属Diglyphus之间。确定这两种姬小蜂的系统发育位置将有助于分析盾纵沟的演化模式。本文用贝叶斯方法分析了线粒体COⅠ 部分序列、核糖体ITS1 序列及核糖体28S D2 区部分序列等3个基因序列,结果显示可疑瑟姬小蜂应被移到潜蝇姬小蜂属中; 研究结果支持潜蝇姬小蜂属是单系,而不支持瑟姬小蜂属是单系。结合28S D2 区部分序列的贝叶斯分析结果,分析了在姬小蜂亚科中盾纵沟的演化模式。结果显示,完整且延伸到中胸背板后缘的盾纵沟代表其原始类型;完整且延伸到三角片的盾纵沟类型分别出现在5个独立的枝上,代表了该特征5次独立的演化;不完整的盾纵沟类型出现在4个独立的枝上,表明该类型独立演化了4次     

中国珊瑚菌一新记录属——扁枝瑚菌属

报道了中国热带珊瑚菌类的一新纪录属——扁枝瑚菌属Scytinopogon。目前该属在我国仅在云南的西双版纳采到两种,即扁枝瑚菌S. pallescen和刺孢扁枝瑚菌S. echinosporus。文中对这两个种进行了描述,并附有插图。研究标本保存于中国科学院昆明植物研究所隐花植物标本室(HKAS)。     

拟隐脉叶蝉属三新种记述(同翅目,叶蝉科,隐脉叶蝉亚科)

记述了拟隐脉叶蝉属Sophonia 3新种,即斜纹拟隐脉叶蝉S．obliquizonata sp．nov．,细纹拟隐脉叶蝉S.lineala sp．nov．和枝突拟隐脉叶蝉S．branchuma sp．nov．。模式标本保存在贵州大学昆虫研究所。     

基于Adh1基因分析高梁属的系统进化关系

高梁属中有重要的粮食作物和优良牧草,也有农业生产上的重要杂草。文章旨在进一步从分子水平阐明高梁属种间的系统进化关系,为有效利用种质资源进行分子育种改良作物品质提供理论依据,并明确检疫性杂草的分类地位。根据二色高粱（Sorghum bicolor）的Adh1全基因序列（GenBank登录号：AF050456）设计引物,扩增并测定黑高梁（S．almum）、假高梁（S．halepense）、丝克高粱（S．silk）和苏丹草（S．sudanense）共计8个植物材料约2000bp的Adh1基因部分序列,结合GenBank中其他24个Sorghum属的同源序列,以Cleistachne sorghoides的对应序列为外群,进行了高梁属的亲缘关系分析,用MP、ML和NJ法分别构建了分子进化树,得到了基本相同的拓扑结构。结果显示：（1）高梁属可明显分为三大支,一支是蒴柄高梁（Chaetosorghum）和异高梁（Heterosorghum）二个亚属,一支是优高梁亚属（Eusorghum）,这两个分支包含2n=20、40,染色体较小的种类,另一分支包括拟高梁（Parasorghum）和有柄高梁（Stiposorghum）两个亚属,包含2n=10的种类和它们的多倍体近缘种,染色体相对较大;（2）S．almum的Adh1基因表现出明显的地理分化;（3）Parasorghum亚属的S.purpureosericeum和多色高粱（S．versicolor）、光高粱（S．nitidum）和S．leiocladum聚在一起,而该亚属中的S.matarankense、S．grande、S．timorense却与亚属Stiposorghum的种聚在一起,表现出更近的亲缘关系;（4）S．macrospermum和S．laxiflorum之间具有比其他高梁属种更近的亲缘关系。     

栝楼属(葫芦科)植物的系统演化与地理分布

依据世界范围栝楼属植物种类的形态学、孢粉学、细胞学、系统发育研究资料,对栝楼属植物的系统演化和现代地理分布的形成进行了总结。栝楼组在栝楼属中处于原始地位,大苞组、叶苞组属于较进化类群,该属内的部分类群是在二倍体的水平上经过多倍化形成的。栝楼属在第三纪时期广布于欧洲、北美洲、亚洲、大洋洲,到第三纪晚期演化进程加快,南亚和中国西南山地逐步成为该属的起源中心与分化中心;受第四纪冰川期影响,该属在欧洲的种类逐渐消失,东亚成为该属的现代分布中心。栝楼属作为中国本地起源种,是中国植物区系中的重要组成部分。     

荨麻科楼梯草属七种植物果实的补充描述

楼梯草属植物的果实形态特征是属下系的划分和种类鉴定的重要依据之一,对于研究该属演化关系具有重要意义。通过标本查阅及野外调查,为该属七种植物的果实进行了补充描述,对该属的进一步分类修订提供有价值的信息。     

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     

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.     

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

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).     

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.