黑龙江省长白落叶松八齿小蠹虫体及坑道的真菌类群

采集落叶松八齿小蠹成虫、幼虫、蛹,以及母坑道、子坑道、蛹室的韧皮组织和蓝变组织。采用马丁氏培养基和PDA综合培养基对各虫态体表、体内、坑道内真菌进行分离培养,统计真菌检出率。对获得的真菌菌株通过形态学和分子生物学相结合的方法进行鉴定。在落叶松八齿小蠹虫体内外和坑道内共分离出真菌24种,其中子囊菌7种,担子菌2种,无性型真菌15种。从各虫态体表共分离出真菌21种,从体内共分离出真菌6种,24种真菌在坑道内均有检出。其中,Ceratocystis fujiensis为检出率较高的蓝变真菌。     

落叶松八齿小蠹体内外和坑道内真菌类群

采集落叶松八齿小蠹成虫、幼虫、蛹,以及母坑道、子坑道、蛹室的韧皮组织和蓝变组织。采用马丁氏培养基和PDA综合培养基对各虫态体表、体内、坑道内真菌进行分离培养,统计真菌检出率。对获得的真菌菌株通过形态学和分子生物学相结合的方法进行鉴定。在落叶松八齿小蠹虫体内外和坑道内共分离出真菌31种,其中接合菌3种,子囊菌8种,担子菌1种,半知菌19种。自各虫态体表共分离出真菌23种,体内共分离出真菌8种,31种真菌在坑道内均有检出。其中,Ceratocystis fujiensis为中国新记录种,Ophiostoma     

大兴安岭地区小蠹虫种类及诱捕器防治研究

本文针对大兴安岭地区的小蠹虫种类进行研究,并通过诱捕器的试验诱集结果,着重研究了小蠹虫的诱捕器防治方法,结果表明落叶松八齿小蠹、云杉八齿小蠹和纵坑切梢小蠹为针叶树的优势种类,诱集结果也证明这3种小蠹的数量占多数,其中落叶松八齿小蠹占绝大多数。     

内蒙古阿尔山地区落叶松八齿小蠹天敌及其控制作用

通过对内蒙古阿尔山地区落叶松八齿小蠹Ipssubelongatus Motschulsky天敌的种类调查,目前共发现落叶松八齿小蠹天敌包括捕食性天敌红胸郭公虫Thanasimus substriatus Gebler,寄生性天敌暗绿截尾金小蜂Tomicobia seitneri(Ruschka)、长蠹刻鞭茧蜂Coeloides bostrichorum Giraud以及螨类、微生物。分析了天敌的自然控制作用,红胸郭公虫对落叶松八齿小蠹成虫的日均捕食率为3.1%±0.77%(落叶松八齿小蠹成虫20头和红胸郭公虫成虫1头,室外12～24℃),日最大捕食量为10.7头(1头红胸郭公虫成虫与20、40、60和80头、100头落叶松八齿小蠹成虫,室内17～25℃);暗绿截尾金小蜂对落叶松八齿小蠹幼虫的寄生率为20.5%,对其蛹的寄生率为13.7%;长蠹刻鞭茧蜂对其幼虫的寄生率为6.5%;螨类对其成虫的寄生率为20.2%;而微生物对落叶松八齿小蠹幼虫的寄生率为4.3%,对蛹的寄生率为5.4%,对成虫的寄生率为2.1%。暗绿截尾金小蜂是落叶松八齿小蠹最有利用价值的天敌昆虫。     

落叶松八齿小蠹坑道在落叶松立木上的垂直分布特征

应用多个聚集度指标和Iwao,Taylor等的回归分析法对落叶松八齿小蠹Ips subelongatus Motschulsky坑道的垂直分布型进行了研究.结果表明:落叶松八齿小蠹坑道数量与落叶松树干不同高度变化成线性关系,拟合的直线方程为y=-10.867x+92.884;落叶松八齿小蠹坑道基本属于均匀分布;坑道的分...     

进口美国松木中截获齿小蠹的鉴定(鞘翅目:小蠹科)

本文对2010—2015年全国口岸从美国进境松木中截获的齿小蠹进行了分析,分别对美云杉齿小蠹Ips borealis、美雕齿小蠹I.calligraphus、混点齿小蠹I.confusus、重齿小蠹I.duplicatus、南部松齿小蠹I.grandicollis、蒙大拿齿小蠹I.montanus、似混齿小蠹I.paraconfusus、白云杉齿小蠹I.perturbatus、美松齿小蠹I.pini、平额重齿小蠹I.plastographus、十二齿小蠹I.sexdentatus、云杉八齿小蠹I.typographus 12种昆虫的进境寄主进行统计,对截获频次进行分析对其成虫的主要形态特征进行了描述,编制了分种检索表,对检疫鉴定工作具有指导意义。     

阿尔山落叶松主要蛀干害虫的种群空间生态位

对阿尔山落叶松主要蛀干害虫的种群生态位进行了研究,结果表明:在落叶松衰弱立木上,生态位宽度以落叶松八齿小蠹最高,在中龄和老龄树上分别达到0.5782、0.5498,在落叶松中龄和老龄枯死立木上,白带长角天牛的空间生态位宽度分别达到0.5143、0.6294,分布较衰弱木广,而云杉大黑天牛空间生态位宽度在衰弱和枯死立木上都最低。落叶松立木上的空间生态位重叠指数以落叶松八齿小蠹对其他3种优势天牛偏高,天牛之间的空间生态位相似性比例指数均较高且差距较小,说明4种害虫对空间生态位的占据有很大相似程度。4种害虫的空间种间竞争系数均很大,说明对空间和资源的竞争非常激烈,在这种情况下4种害虫能够共存,根本原因是由于取食部位的分化。     

危害松树的小蠹虫与其伴生茵的相互关系

危害健康松属植物的小蠹虫经常与一些特殊的真菌相联系.在小蠹虫危害松属植物的过程中,这些真菌被小蠹虫的一些特殊结构或者体表携带到松属植物上.小蠹虫与其伴生菌的联系表明小蠹虫和其伴生菌之间是一种互惠互利的关系.伴生菌随小蠹虫扩散而被带到新的寄主树木.而伴生菌或作为小蠹虫的食物来源,但更重要的是,有些伴生菌能够通过其菌丝渗透寄主组织,释放毒素,致死寄主树木,以帮助小蠹虫降低寄主抗性.许多研究致力于探索小蠹虫/伴生菌联合体与寄主树木之间关系的特征和确定小蠹虫与其伴生菌相互关系在生态学上的意义.然而,不同小蠹虫和其伴生菌所组成的共生体系,不同小蠹虫的种群数量,和不同环境条件下同种小蠹虫与其伴生菌相互作用方式的差异使我们在研究小蠹虫和其伴生菌这个共生体系时,对它们各自在成功聚集寄主树木过程中所发挥的重要作用的概括变得非常困难.     

小蠹虫类异戊二烯类聚集信息素的生物合成

小蠹虫(小蠹科)是重要的森林蛀干害虫,在蛀食坑道时导致树木水分和养分运输系统受到破坏,短时间内对整片森林造成严重的经济危害。聚集信息素在小蠹虫聚集危害过程中扮演着非常重要的角色,目前已有多种小蠹虫聚集信息素成分被鉴定并成功应用于生产防控工作中。类异戊二烯类聚集信息素是小蠹虫中极为重要的一类聚集信息素,其主要成分包括小蠹烯醇、小蠹二烯醇、马鞭草烯醇及其衍生物。本文从类异戊二烯类聚集信息素的生物合成前体物质、生物合成位点、生物合成途径、取食和JHШ调控、微生物与其生物合成关系以及展望6个方面出发,全面阐述了齿小蠹属Ips和大小蠹属Dendroctonus中小蠹虫聚集信息素的生物合成机制及调控机制。文中首先重点阐述了小蠹虫体内以甲羟戊酸途径从头合成小蠹二烯醇以及利用寄主成分α-蒎烯直接合成马鞭草烯醇的生物合成过程;其次阐述了生物合成途径中关键酶和基因对小蠹取食和JHШ处理的响应以及小蠹虫肠道微生物和伴生真菌对该类聚集信息素生物合成的影响;最后,针对小蠹虫类异戊二烯类聚集信息素生物合成研究作了探讨和展望。本文为开发和应用其聚集信息素控制小蠹虫危害提供理论基础。     

光臀八齿小蠹共生微生物群落组成及其功能基因注释

【目的】揭示光臀八齿小蠹Ips nitidus共生微生物群落组成和功能特征。【方法】对来自中国西北部青海省麦秀自然保护区的光臀八齿小蠹进行肠道和其他组织共生真菌和细菌宏基因组学和相关性网络分析，比较光臀八齿小蠹肠道和其他组织共生真菌及细菌群落组成，分析微生物群落间的相互关系，并采用非冗余蛋白序列比对方法注释共生微生物功能基因。【结果】共发现光臀八齿小蠹肠道和其他组织共生微生物3 520种，真菌和细菌的物种数最高，分别占全部物种数的23.21%和69.01%,平均相对丰度分别为9.69%和13.79%。其他组织中共生真菌白粉菌目(Erysiphales)相对丰度和物种多样性较肠道中的高，而其他组织中酵母目(Saccharomycetales)相对丰度和物种多样性较肠道中的低；其他组织中长喙壳类真菌(ophiostomatoid fungi)多样性(6属16种)较在肠道中的(5属13种)高，在其他组织和肠道中的平均相对丰度分别为0.016%和0.013%。其他组织中肠杆菌目(Enterobacterales)相对丰度和物种多样性高于肠道中的。肠杆菌属Enterobacter、白粉菌属Ery...     

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.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

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.     

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).