天敌瓢虫种群遗传学及其在生物防治中的应用

天敌瓢虫常在农业生产的生物防治中被广泛引进和使用。这种使用过程往往会导致天敌瓢虫在遗传水平的改变,并最终影响到其生物防治的使用效果和本地生态多样性。对天敌瓢虫种群遗传学的研究,有助于我们认识甚至预测这种遗传改变的规律和生态机制,从而为生物防治计划的优化提供理论基础。本文介绍了种群遗传学的研究方法,分析在生物防治中促进天敌瓢虫遗传改变的因素,以及几种常见的天敌瓢虫种群演变情况,并讨论种群遗传学在天敌瓢虫研究的未来方向。     

载体植物在温室作物害虫生物防治中的应用

增补式生物防治是利用天敌昆虫或捕食螨防治害虫最常用的方法,释放的天敌昆虫或捕食螨能否成功建立稳定种群,是决定其持久高效控害的首要关键因素。然而在生产应用中,经常因释放的天敌昆虫或捕食螨不能成功定殖而无法达到理想的防治效果。载体植物系统是天敌饲养和释放的新方法,结合了增补式和保护式生物防治的优点,既能实现天敌昆虫或捕食螨的大量饲养,又能为释放的天敌昆虫或捕食螨提供替代食物和栖息场所,促进其建立稳定的种群,对实现天敌昆虫或捕食螨高效持久控害具有重要的意义。本文系统介绍了载体植物系统的构建、国内外研究现状,指出了现存的问题,并给出相应的建议。     

基于CNKI分析的我国农田捕食性昆虫资源与应用

【目的】了解我国农田捕食性昆虫资源与应用研究态势。【方法】应用文献计量学方法,分析中国知网(CNKI)收录的全部年代的我国农田捕食性昆虫的中文文献。【结果】提取到544篇与农田捕食性昆虫相关文献及包含在这些文献中的1 747条关键信息词,研究内容主要包括以下5个方面:农田节肢动物群落与捕食性优势种;农田重要捕食者;捕食作用、食物网关系与生态服务价值评价;人工繁育、人工饲料与天敌释放应用;主要农作物的重要害虫种群及其综合管理。水稻与棉花生态系统及其中的捕食昆虫与害虫被重点关注。异色瓢虫Harmoniaaxyridis、七星瓢虫Coccinellaseptempunctata、龟纹瓢虫Propyleajaponica、黑肩绿盲蝽Cyrtorhinuslividipennis、青翅蚁形隐翅虫Paederusfuscipes、稻红瓢虫Micraspisdiscolor、尖钩宽黾蝽Microveliahorvathi等是农田中的优势性捕食性昆虫。【结论】在我国主要农田生态系统中,存在着丰富的捕食性昆虫资源,它们扮演着农作物害虫天敌的角色,实现对农作物害虫的生物防治或自然控制。建议加强对重要害虫种群发生机制研究,促进有利于天敌生存、保存的条件与方法研究,提高天敌的生态防控效能。     

北疆棉田捕食性天敌昆虫应对棉蚜的数量反应

【目的】棉蚜Aphis gossypii是新疆棉田的主要害虫,近来的研究多集中于南疆棉区,较少关注北疆棉田在新种植模式下的天敌种群数量发生规律。本文研究了北疆棉田棉蚜的优势种捕食性昆虫数量发生规律。【方法】对五家渠地区棉田中棉蚜及其4种主要捕食性天敌昆虫(2种瓢虫和2种草蛉)的种群数量进行了持续2年的跟踪调查。【结果】不同种捕食性天敌昆虫对棉蚜种群数量变化具有不同的响应,具体表现为:七星瓢虫Cocinella septempunctata数量随蚜虫数量增大而显著增大,多异瓢虫Hippodamia verigata和普通草蛉Chrysopa carnea随蚜虫数量增大而逐渐增大,而大草蛉Ch.septempunctata种群数量与棉蚜数量无关;连续2年的大田调查均发现,这4种捕食性昆虫种群数量在7月底有一高峰,而且七星瓢虫和大草蛉数量大于多异瓢虫和普通草蛉。【结论】七星瓢虫和大草龄是北疆五家渠地区棉田棉蚜的优势天敌。     

异色瓢虫规模化生产技术及瓢虫工厂的建立

异色瓢虫Harmonia axyridis(Pallas)是一种重要的捕食性天敌,工厂化人工饲养异色瓢虫是利用其进行蚜虫等小型害虫生物防治的有效手段。本文报道了在河南省济源白云实业有限公司建立的基于甜菜夜蛾Spodoptera exigua(Hübner)低龄幼虫的工厂化生产的技术流程。利用这一技术,可以大量、稳定地生产异色瓢虫各虫态个体,基本实现了异色瓢虫的工厂化生产。文中还探讨了异色瓢虫产业化进程中存在的问题,期望瓢虫天敌产业化和商业化能够有所突破。     

气候变化预计会减少东亚地区豚草的生物防治效果

外来入侵植物对入侵地的生态系统与社会经济可造成严重的威胁。如何控制入侵植物对自然资源的危害,向人类提出了极大的挑战。利用原产地的专食性天敌来控制入侵植物已被广泛证明是一种经济、可持续的生物防治手段。在全球气候变暖的背景下,生物防治研究的关键问题是全面了解物种的潜在分布区和传播范围,进而优化入侵植物的生物防治方案。本研究利用生物地理模型,通过预测两种生物防治昆虫和它们的组合在东亚地区的适宜分布区,预测豚草(Ambrosia artemisiifolia)的生物防治区域。豚草原产北美,目前已经入侵全球多个国家和地区。20世纪末,豚草条纹叶甲(Ophraella communa)和豚草卷蛾(Epiblema strenuana)作为豚草的生物防治昆虫从原产地引入到东亚地区。本研究旨在探讨如下问题:(1)在豚草的适宜生长分布区内,有多少区域也同样适宜其两种天敌的生存?(2)在目前和未来的气候背景下,有多少区域适宜豚草生长但是不适宜它的两种天敌生长?(3)在这些适宜豚草生长却不适宜两种昆虫天敌生长的区域内,需要选择哪些特定的生物型进行投放?为此,我们基于入侵植物和两种生物防治昆虫的全球分布记录及其分布点的重要生物气候因子,同时模拟了入侵植物及其两种生物防治天敌在东亚地区的分布范围。排序技术被用来探索气候因子对每个物种的限制作用,同时也用来检验豚草在北美和东亚地区的生态位重叠和相似性。结果表明,在当前和未来的气候背景下,相较于豚草卷蛾,豚草条纹叶甲与豚草的地理分布范围更加吻合(当前气候:40.3%vs.21.6%,未来气候:29.8%vs.20.3%)。气候变化可能会导致两种生物防治天敌(尤其是豚草条纹叶甲)的地理分布与豚草的地理分布的重叠区域减少(42.9%vs.29.9%)。本研究同时提出了温度和降水等气候因子可用于为特殊区域(生物防治天敌未覆盖的豚草分布区)筛选生物防治天敌的相应株系。     

朱砂叶螨优势种天敌昆虫的评价

对绣球花Hydrangea macrophylla、茄子Solanum melongena和玉米Zea mays 3种植物上朱砂叶螨Tetranychus cinnabarinus天敌昆虫种类及发生数量进行调查,并采用优势度指数评价其优势种,结果表明,3种寄主植物上天敌的种类及其优势种有所不同,绣球花上有深点食螨瓢虫Stethorus punctillum、塔六点蓟马Scolothrips takahashii、食螨瘿蚊Acaroletes sp.和食螨隐翅虫Oligota sp.4种天敌,塔六点蓟马和深点食螨瓢虫为优势种;茄子上有塔六点蓟马、微小花蝽Orius minutus、食螨瘿蚊和深点食螨瓢虫4种天敌昆虫,塔六点蓟马为优势种;玉米上有深点食螨瓢虫、塔六点蓟马和食螨瘿蚊3种天敌昆虫,深点食螨瓢虫为优势种.通过测定各种天敌成虫和幼虫对朱砂叶螨成螨、若螨、幼螨和卵的日捕食量,并引入相对差距和法评价优势种天敌昆虫,结果表明,深点食螨瓢虫和微小花蝽是朱砂叶螨的优势种天敌.     

三种捕食性瓢虫成虫对卵的种内自残及其集团内捕食作用

捕食性瓢虫是农田生态系中一类重要的天敌昆虫,种内自残和集团内捕食现象在捕食性瓢虫中普遍存在。本研究在室内通过选择性和非选择性试验比较分析了异色瓢虫、七星瓢虫及龟纹瓢虫成虫对卵的种内自残和集团内捕食作用以及卵表面的化学物质对集团内捕食作用的影响。结果表明:在非选择性试验中,3种捕食性瓢虫成虫对卵表现出相似的取食现象,即对龟纹瓢虫卵取食最多,其次为七星瓢虫卵,对异色瓢虫卵取食相对较少;在选择性试验中,七星瓢虫和龟纹瓢虫较偏好取食同种卵,对异色瓢虫卵取食均较少;而异色瓢虫喜欢取食异种卵,对同种卵取食相对较少。3种瓢虫卵经正己烷漂洗后,异色瓢虫、七星瓢虫和龟纹瓢虫成虫却未对卵表现出取食偏好性。本研究可为捕食性瓢虫组合释放与协调利用、田间集团内捕食作用评定及其在生物防治中的应用提供理论依据。     

孟氏隐唇瓢虫研究现状及其种质资源描述规范的建立

孟氏隐唇瓢虫Cryptolaemus montrouzieri Mulsant原产于澳大利亚,是粉蚧的重要捕食性天敌,作为生物防治重要的天敌资源被广泛引进世界各地.本文介绍了国内外近几十年来对孟氏隐唇瓢虫在生活史、行为、抗药性以及生物防治等方面的研究概况,并提出建立孟氏隐唇瓢虫种质资源描述规范的必要性,为充分发挥其控害潜能提供理论依据.     

释放天敌瓢虫和施用化学农药吡虫啉对麦田蚜虫的控制效果评价

以常规防治农药甲胺磷做对照,比较高效低毒化学农药吡虫啉和天敌昆虫瓢虫对田间麦蚜的防治效果。结果表明,施用10%吡虫啉可湿性粉剂300ghm2药后5d和10d的防效分别为15.1%和31.1%,对麦蚜防效理想。释放天敌昆虫瓢虫后5d和10d的防效分别为-347.6%和-171.7%,防效差,这是由于释放天敌后的强降雨所致。     

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