广西中越边境的外来入侵植物

【目的】广西中越边境是中国通往东盟各国的重要通道。近年来,外来入侵植物对该地区的生态安全和经济发展都产生了严重的威胁。为有效预防和控制中越边境的外来入侵植物,保障中越边境地区生态安全和经济健康发展,需要掌握中越边境外来入侵植物的基本信息。【方法】通过实地调查、拍照和采集标本,分析广西中越边境外来入侵植物的种类组成、生活型和危害程度等;通过文献资料,了解所调查外来入侵植物的原产地和入侵途径等。【结果】广西中越边境外来入侵植物共121种,隶属于38科,其中菊科最多,有26种,豆科次之,有11种;外来入侵植物以草本为主,有102种,占总种数的84.30%;原产地来源最多的是美洲,有92种,占总种数的68.66%;人为有意引入有68种,占总种数的56.20%;严重危害的有23种,中等危害的有32种,一般危害的有66种。【结论】广西中越边境外来入侵植物种类多且分布范围广、传播途径复杂、危害严重种类多,急需对广西中越边境的外来入侵植物进行预防和控制,特别是要严密监控新发生入侵种类的动态,积极控制已产生危害的严重种类,实行预防为主、防治结合的原则。     

海口市外来入侵植物现状及防控对策

基于野外调查及文献资料及标本信息查阅,基本查清海口市外来入侵植物的种类组成、原产地、生活型、入侵途径,并对外来入侵植物在海口市的入侵危害进行等级划分。结果表明,海口市目前发现外来入侵植物115种,隶属于32科83属,其中菊科种数最多,有23种,占海口外来入侵植物总种数的20.0%;有92种原产地为美洲,占80.0%;有84种为草本植物,占73.0%;有111种为人类有意或无意引入,占96.5%;入侵植物中严重危害类(1级)有12种,一般危害类(2级)有24种,潜在危害类(3级)有25种,一般外来类(4级)有22种,32种还有待观察(5级)。文中提出对海口外来植物入侵的防控及管理对策。     

海南岛的外来植物

通过对海南岛野生或半野生外来入侵植物的调查,报道了153种外来植物,并对近年来在海南岛大面积分布而未报道过的入侵种进行简要介绍。对海南外来植物种类组成、原产地、生活型与危害程度的分析发现:(1)外来植物中有66.67%来自美洲,美洲种的96%为热带美洲成分,几乎所有来自美洲的草本植物往往成为遍布海南各地农田、果园、胶林、草地的有害杂草;(2)外来草本与藤本植物具有较强的入侵能力和较大的危害;(3)绝大多数草本与藤本植物常形成单一优势群落,破坏平地、低丘陵原有的生态系统。     

平潭无居民海岛外来入侵植物特征分析

【目的】摸清平潭无居民海岛外来入侵植物的现状,为海岛外来入侵植物防治及海岛植被修复等提供参考。【方法】采用样线法和样方法,开展平潭无居民海岛外来入侵植物的调查,对其科属组成、区系地理成分、植物功能性状特征、原产地和入侵等级等进行统计分析,并与其他海岛区域进行对比研究。【结果】平潭无居民海岛共有外来入侵植物15科26属30种,以菊科、苋科较为突出,科、属级地理成分都以热带成分为主。在植物功能性状方面,生活型、生长型均以一年生草本为主;叶以小型叶、纸质叶、叶被毛比重最大;果实及种子特征以微型的蒴果、瘦果、胞果为主。海岛外来入侵植物原产地主要为美洲;入侵方式多为人为或其他活动无意引入,且危害方式多样,破坏性强;繁殖方式以种子繁殖为主;8种外来入侵植物的出现频率≥27.78%;研究区外来入侵植物特征与其他海岛区域外来入侵植物特征具有一定相似性。【结论】平潭无居民海岛外来入侵植物种类较多、部分植物入侵性较强及出现频率较高等,建议继续开展平潭其他海岛外来入侵植物的本底调查,并有针对性地开展防治工作。     

中国公布的3 批外来入侵植物种类特征与入侵现状分析

生物入侵是当今世界各国发展的一大挑战。外来入侵物种已对各国经济造成了不同程度的影响, 中国也未能幸免。为了防止外来物种入侵, 减轻其对我国造成的影响, 国家环保总局先后于2003 年、2010 年及2014 年公布了3 批中国外来入侵物种名单。据统计, 中国公布的3 批外来物种名单中的外来入侵植物共29 种, 占半数以上, 其中菊科和禾本科植物合计20 种, 约占3 批外来入侵植物总种数的68.96%; 生活型为草本的植物最多, 占96.55%; 原产地为美洲的占93.10%。3 批外来入侵植物中62.07%的植物是非有意引入的, 现今已全部建立种群, 且在全国各地大范围扩散。     

安徽省外来入侵植物的分布格局及其等级划分

区域性外来入侵植物的研究及其入侵等级划分在地方入侵植物管理与防治对策的制定上具有重要的指导意义。本文基于文献报道、标本记录和必要的分类学考证,特别是通过2013-2015年对安徽省外来入侵植物的全面调查,统计分析了安徽省外来入侵植物的物种组成、生活型、原产地、区系组成和水平分布格局,并对其入侵危害进行等级划分。结果显示,安徽省有外来入侵植物37科86属132种,总体上呈现种类丰富、原产于美洲的种类多、泛热带起源的种类多、危害严重的种类多、区域分化明显、入侵途径集中等特征。提出在外来入侵植物的防控中应重点警惕起源于美洲的、泛热带分布属的植物和关注人类活动频繁的热点区域。还对中国外来入侵植物研究中存在的问题进行了探讨,澄清了几个长期以来被忽视的关于外来入侵物种认知的问题。     

湛江市外来植物入侵状况

[目的]了解湛江市外来入侵植物的种类特征、生活型、起源和危害情况等,对制定预防和控制管理措施提供参考。[方法]以野外调查为主,结合文献资料、网络资源以及标本数据,确定湛江市外来入侵植物的种类、生活型、原产地、引入途径,并进行评估及划分危害等级。[结果]湛江市现有外来入侵植物共112种(含变种),隶属于37科89属,其中,菊科(21种)、禾本科(13种)和豆科(13种)为种类较多的3个科,三者合计占湛江市外来入侵植物总种数的41.96%。湛江市外来入侵植物中以草本植物居多(98种),占入侵植物总数的87.50%。入侵植物主要来源于美洲,共82种,占总种数的73.21%;且55.36%(62种)的入侵植物为有意引入。从危害等级看,外来入侵植物中恶性入侵种(1级)23种,严重入侵种(2级)35种,局部入侵种(3级)21种,一般入侵种(4级)15种,有待观察种(5级)18种。[结论]湛江市的外来入侵植物种类繁多,这与湛江独特的地理位置以及日趋频繁的人类活动息息相关,应当加强监管与防范,及时对外来物种进行治理。     

广州外来入侵植物

根据野外调查及相关文献资料,初步探讨了广州市外来入侵植物的种类组成、分布生境、生长特性、危害以及来源.结果表明:广州市现有外来人侵植物73种,隶属于27科59属,其中菊科(19种)、禾本科(8种)、豆科(7种)和苋科(7种)植物占了入侵植物总种数的56.2%.生活型分析发现,在广州有分布的外来入侵植物中,陆生草本植物最多(58种),其次为灌木(10种)、水生草本(3种),乔木种类最少(2种),它们主要生长在人类干扰比较频繁的低海拔地区.另外,基于对外来入侵植物目前在野外的生长和分布状况等生态学特性进行分析,可大致将它们对本地生物多样性危害程度分为3级,其中危害严重的有11种,危害中等的有25种,危害较轻的有37种.从原产地分析来看,61种来自于热带美洲地区,占广州外来入侵植物总种数的83.6%.与国内其他地区外来入侵植物进行比较发现,广州和广西共有种数最多,有62种,然而,对已经造成严重危害的外来植物种类,在数量上广州与香港、深圳和广西相同种类较多,分别有8种、7种和6种.对广州市目前外来植物的入侵风险(潜在威胁)的评估结果表明,对一些在其它地区已经造成严重危害的外来植物,应当加强监控,防止入侵扩散并造成重大生态灾难.还对广州市外来植物入侵的主要途径及防治策略做了简要分析和说明.     

浙江省外来入侵植物研究

基于国内外文献资料、标本信息和野外调查,初步整理了浙江省外来入侵植物的种类组成、生活型、原产地、危害程度和入侵途径。结果表明,浙江省现有外来入侵植物46科106属166种,种数最多的是菊科、豆科和禾本科。根据原产地分析,来源于南美洲的物种最多,约占总数的3216%,其次为北美洲,约占总数的2563%,欧洲排第三位,约占总数的1959%;已产生严重危害的有23种,中等危害的60种,危害较轻的83种。还有一些物种虽然没有在表里列出,但它们具有潜在的危害,必须密切关注。同时,与之前的研究相比,我们去除了一些已报道为入侵的物种,又增加了一些新的入侵种。在此基础上,对浙江省外来入侵植物的生活型、来源及危害进行了分析,并与以往的研究进行了比较,提出了针对性的管理建议。     

中国香港外来入侵植物

该文于2015—2016年通过野外实地调查并结合整理、查阅相关的文献资料,研究了中国香港特别行政区外来入侵植物的种类组成、原产地、生活型、入侵途径和危害状况等。结果表明:(1)中国香港有外来入侵植物共101种,隶属于36科77属,其中菊科(Asteraceae)植物的种类最多,有17种。(2)来源于美洲的外来入侵植物种类最多,占入侵植物总数的77.2%。(3)外来种类中草本植物占了绝大多数,占总种数的80.2%。(4)恶意入侵与严重入侵植物共42种,占总种数的41.6%。同时,通过与邻近的珠海、深圳、澳门、广州四个地区的外来入侵植物进行比较,提出了珠三角区域共防共治外来植物入侵、保障环境生态安全的建议。     

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.