烟粉虱生物型的监测及其遗传结构研究

烟粉虱Bemisia tabaci(Gennadius)是一种重要的农业害虫并包括许多生物型,其中B型和Q型是入侵性较强的2种生物型。文章着重介绍近年来在烟粉虱生物型的监测及其遗传结构方面的研究进展。B型烟粉虱和Q型烟粉虱这2个生物型均已入侵我国,其中多数地区烟粉虱是B型烟粉虱,局部地区有Q型烟粉虱并呈现不断蔓延趋势。微卫星(SSR)分子标记分析结果表明我国B型烟粉虱的入侵来源具有多元化,而云南地区Q型烟粉虱来源比较单一。化学农药的使用能够影响室内种群的遗传结构,降低种群的遗传多样性。基于RAPD、ISSR分子标记的分析结果表明,Q型烟粉虱种群各项遗传多样性指数均比B型烟粉虱的高。今后加强烟粉虱入侵生物型的遗传结构及其种群动态关系等方面的研究,对于揭示烟粉虱的灾变机制及其控制具有重要的意义。     

烟粉虱生物型研究进展

烟粉虱B em isia tabaci(G ennad ius)是一种取食植物汁液的重要农业害虫,同时也是许多植物病毒最重要的传播介体之一。烟粉虱被认为是由许多具有明显遗传分化的不同种群即生物型组成的复合种,其中B型烟粉虱是一种入侵性最强的生物型,几乎在世界各地均有分布。由于不同生物型的烟粉虱在寄主范围、传毒能力、地理分布、抗药性等许多生物学方面存在差异,因此对烟粉虱生物型的鉴定及其遗传分化研究对于该害虫的可持续控制具有重要的指导意义。烟粉虱生物型的鉴定方法包括生物学鉴定、酶谱鉴定以及分子标记鉴定的方法,其中使用的分子标记包括RAPD、AFLP、rDNA-ITS1、m tDNA CO I以及SSR等标记。目前,不同生物型的烟粉虱尤其B型烟粉虱的分类地位仍然存在争议。介绍了不同生物型烟粉虱的生物学差异、鉴定方法及其遗传分化研究的最新进展,同时探讨了不同生物型烟粉虱的分类地位和研究方向。     

基于16S rDNA基因的中国部分地区非B型烟粉虱系统发育关系分析

【目的】烟粉虱Bemisia tabaci是一个快速进化的复合种。由于近年来烟粉虱危害不断增加, 其生物型问题也越来越受到关注。在我国, 不仅存在危害严重的B型烟粉虱, 同时也已发现多种非B型烟粉虱。通过鉴定我国部分地区目前发生的烟粉虱生物型种类, 分析它们与世界各地不同生物型之间的关系, 可为我国烟粉虱的生物型检测和综合防治提供依据。【方法】利用16S rDNA基因作为分子标记, 鉴定了2005年与2006年在我国6个省份（自治区）采集的22个非B型烟粉虱样本的生物型, 并探讨了各生物型之间的系统进化关系。【结果】所研究的22个非B型烟粉虱归属于Q型、Nauru型和An型, 3种生物型之间的遗传距离在10%以上, 但是Q生物型与B生物型之间的亲缘关系最近, 遗传距离在2.8%~4.0%范围内; 进化分歧数据还表明, 不同生物型之间的遗传距离明显大于同一生物型内遗传距离, 其中Q型内部差异最小, 在0.9%以内; 同时结果表明目前在我国多个生物型共同存在是一个普遍的现象, 其中Nauru型的分布较广泛; 在云南地区检测到的非B型烟粉虱生物型类型最多。【结论】烟粉虱生物型遗传分化复杂, 利用16S rDNA基因能有效鉴定烟粉虱的生物型。     

褐飞虱生物型特异性蛋白质研究

褐飞虱生物型特异性蛋白质研究方继朝,杜正文,夏礼如,孙建中（江苏省农业科学院植物保护研究所南京２１００１４）褐飞虱是我国及东南业水稻重人害虫。利用抗虱基因、培育推广抗虫品种是综合治理褐飞虱的优先策略,在水稻牛产上发挥了重要作用［１］。但褐飞虱的牛物型...     

水稻抗褐飞虱基因研究和利用现状

稻褐飞虱(Nilaparvata lugens Stal)是一种单食性水稻害虫,根据其对水稻品种的危害,可分为生物型1、2、3、4等类型.它对亚洲各国水稻生产造成极大危害.实践证明,利用抗虫品种是防治稻褐飞虱最经济有效的方法.本文综述了稻褐飞虱的生物学特征和分布、生物类型,着重介绍抗稻褐飞虱基因的研究和利用现状,并对今后开展抗稻褐飞虱基因研究提出几点建议.     

水稻抗褐飞虱基因研究和利用现状

稻褐飞虱（Nilaparvata lugens Stal）是一种单食性水稻害虫,根据其对水稻品种的危害,可分为生物型1、2、3、4等类型。它对亚洲各国水稻生产造成极大危害。实践证明,利用抗虫品种是防治稻褐飞虱最经济有效的方法。本文综述了稻褐飞虱的生物学特征和分布、生物类型,着重介绍抗稻褐飞虱基因的研究和利用现状,并对今后开展抗稻褐飞虱基因研究提出几点建议。     

褐飞虱生物型研究进展:致害性变异的遗传机制

能够“克服”水稻抗性的褐飞虱生物型的出现 ,是目前水稻育种及害虫防治工作中面临的重大难题。为探明褐飞虱生物型的形成机制 ,许多学者致力于生物型致害性的遗传学研究 ,然而得出的结论却不尽一致。该文综述了有关褐飞虱生物型研究中争论较多的 3个方面 ,即生物型致害性的稳定性 ,致害性的遗传机制 ,以及生物型的形成机制 ,并介绍了最新的研究进展 ,展望了该领域的研究方向     

突尼斯两种麦瘿蚊的遗传变异和相关性分析

小麦黑森瘿蚊Mayetiola destructor Say和大麦茎干瘿蚊M. hordei Kieffer是在突尼斯每年都可导致谷物重大损失的两个植食性姊妹种。通常认为为害小麦的瘿蚊是小麦黑森瘿蚊,但是不同谷类物种（小麦或大麦）与麦瘿蚊的这两个种（ destructor 或 hordei ）之间寄主关系并不很严格。提出有效的害虫管理方案首先要求对瘿蚊基因型进行精确分析。本研究应用随机扩增多态DNA（RAPD）技术,结合交配分析和线粒体DNA分型技术,对位于突尼斯北部的一个为害小麦的麦瘿蚊种群的遗传变异程度和分类关联性进行了评估。基于RAPD结果的系统发育分析表明,所研究的种群具有较大的遗传变异范围,这可能源于被分析的小麦样品有被两种瘿蚊共同侵害的复杂背景。虽然交配分析表明有少数不能成功产卵(2/14),但是基于细胞色素b基因限制性酶切分析显示全部样品的线粒体分型均属M. destructor。本文结果进一步证明以RAPD可变性作为分类推断依据不可靠,还为突尼斯M. destructor和M. hordei属于异域分布的观点提供了补充证据。     

烟粉虱B型与Q型种群遗传多样性的AFLP分析

烟粉虱Bemisia tabaci(Gennadius)是由多种生物型或物种组成的复合种。Q型烟粉虱在我国部分地区正在取代B型烟粉虱成为优势生物型。烟粉虱Q型与B型遗传多样性比较研究为解析这2种生物型入侵的遗传学基础具有重要的意义。本文利用AFLP技术研究了Q型(包括Q1型、Q2型)、B型烟粉虱种群的遗传多样性。结果表明:Q型烟粉虱遗传多样性高于B型烟粉虱;Q1型烟粉虱各项遗传多样性指数均接近于Q2型。最后探讨了AFLP与SSR分子标记的各自特点。     

B型烟粉虱的入侵机理与控制基础——国家重点基础研究发展计划“农林危险生物入侵机理与控制基础研究”进展

针对B型烟粉虱入侵后的暴发性及生态系统的可侵入性,开展了B型烟粉虱的入侵机制、成灾机理和控制基础研究.结果显示,目前我国至少存在6种生物型（B,Q,ZHJ-1,ZHJ-2,ZHJ-3,FJ-1）,其中B型烟粉虱在我国大部分地区、Q型烟粉虱在我国长江流域已成为优势种群,给蔬菜、花卉和棉花生产造成严重危害.寄主植物、地理环境及杀虫剂可诱导B型烟粉虱产生遗传分化,使其种群遗传结构发生快速演变;黄瓜和南瓜可诱导羧酸酯酶（CarE）和谷胱甘肽S-移酶（GSTs）活性升高,增强B型烟粉虱抗药性;植物次生物可诱导B型烟粉虱解毒酶活性升高.B型烟粉虱所具有的较强的高温胁迫适应能力和热激蛋白基因的表达与响应密切相关.B型烟粉虱可取代土著烟粉虱,B型烟粉虱与土著烟粉虱间的非对称交配干扰及其与植物双生病毒间的互利共生加剧了B型烟粉虱的入侵;特定条件下B型烟粉虱可取代温室粉虱,较强的逆境适应能力、较快的种群增长力可能是B型烟粉虱取代温室粉虱的主要机制;较强的对寄主转换的适应能力与B型烟粉虱寄主谱扩张有关.土著天敌对B型烟粉虱具有较强的控制潜能;B型烟粉虱3,4龄若虫及蜜露可诱导丽蚜小蜂产生强烈的搜索行为,若虫利它素在丽蚜小蜂寄主搜索和定位中具有重要作用.研究结果为阐明B型烟粉虱入侵种群在我国的遗传分化与快速演变机制和分子生态适应机制、探明种群形成与扩张过程中生态对策的调整及其效应提供了理论依据,为B型烟粉虱的生物生态控制途径和持续治理策略提供了保障。     

北京和湖南烟粉虱生物型及其抗药性监测

烟粉虱是蔬菜等园艺作物上为害严重、最难以防治的害虫之一,生产上防治该虫主要还是依靠化学药剂。本研究鉴定了北京、湖南地区设施蔬菜上烟粉虱的生物型,并监测了其对6种不同杀虫剂的抗药性。结果表明,北京、湖南地区蔬菜烟粉虱生物型分别是Q型和B型。两地烟粉虱对阿维菌素尚处于敏感状态;对烯啶虫胺及其他烟碱类杀虫剂噻虫嗪和吡虫啉的抗药性达中抗到高抗水平,湖南地区抗性水平比北京地区更高,抗性倍数最高达到71.58倍;传统杀虫剂毒死蜱和联苯菊酯对湖南、北京两地烟粉虱的毒杀活性差。     

Genetic mutations associated with chemical resistance in the cytochrome P450 genes of invasive and native Bemisia tabaci (Hemiptera: Aleyrodidae) populations in China

Abstract  Bemisia tabaci (Gennadius) is a species complex, and its two most damaging biotypes B and Q are globally distributed pests. Despite increasing biological and economic impacts, little is known about the evolutionary mechanisms that favor their competition with native populations. Here, we investigated the genetic mutations in the P450 gene of the invasive B, Q biotypes and the native Cv population. Four mutations associated with chemical resistance, Pro-Leu, Ala-Ser, Ser-Phe and Trp-Leu, were found in the cytochrome P450 CYP6C and CYP9F genes of the B and Q biotypes. Bioassay results also revealed that both the B and Q biotypes have about 12–47 times more resistance to acephate, beta-cypermethrin, methomyl, and 5–7 times more resistance to imidacloprid insecticide than Cv population. Our results provide a molecular approach for better understanding and monitoring the pesticide resistances of invasive and native B. tabaci populations in China.     

Global relationships of Bemisia tabaci (Hemiptera: Aleyrodidae) revealed using Bayesian analysis of mitochondrial COI DNA sequences

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a species complex that is one of the most devastating agricultural pests worldwide and affects a broad range of food, fiber and ornamental crops. Unfortunately, using parsimony and neighbor joining methods, global phylogenetic relationships of the major races/biotypes of B. tabaci remain unresolved. Aside from the limitations of these methods, phylogenetic analyses have been limited to only small subsets of the global collection of B. tabaci, and thus limited taxon sampling has confounded the analyses. To improve our understanding of global B. tabaci phylogenetic relationships, a Bayesian phylogenetic technique was utilized to elucidate the relationships among all COI DNA sequence data available in GenBank for B. tabaci worldwide (366 specimens). As a result, the first well-resolved phylogeny for the B. tabaci species complex was produced showing 12 major well-resolved (0.70 posterior probability or above) genetic groups: B. tabaci (Mediterranean/Asia Minor/Africa), B. tabaci (Mediterranean), B. tabaci (Indian Ocean), B. tabaci (sub-Saharan Africa silverleafing), B. tabaci (Asia I), B. tabaci (Australia), B. tabaci (China), B. tabaci (Asia II), B. tabaci (Italy), B. tabaci (New World), B. tabaci (sub-Saharan Africa non-silverleafing) and B. tabaci (Uganda sweet potato). Further analysis of this phylogeny shows a close relationship of the New World B. tabaci with Asian biotypes, and characteristics of the major sub-Saharan Africa non-silverleafing clade strongly supports an African origin of B. tabaci due to its position at the base of the global phylogeny, and the diversity of well-resolved sub-clades within this group. Bayesian re-analyses of B. tabaci ITS, COI, and a combined dataset from a previous study resulted in seven major well-resolved races with high posterior probabilities, also showing the utility of the Bayesian method. Relationships of the 12 major B. tabaci genetic groups are discussed herein.     

Host race evolution in Schizaphis graminum (Hemiptera: Aphididae): nuclear DNA sequences

The greenbug aphid, Schizaphis graminum (Rondani) was introduced into the United States in the late 1880s, and quickly was established as a pest of wheat, oat, and barley. Sorghum was also a host, but it was not until 1968 that greenbug became a serious pest of it as well. The most effective control method is the planting of resistant varieties; however, the occurrence of greenbug biotypes has hampered the development and use of plant resistance as a management technique. Until the 1990s, the evolutionary status of greenbug biotypes was obscure. Four mtDNA cytochrome oxidase subunit I (COI) haplotypes were previously identified, suggesting that S. graminum sensu lato was comprised of host-adapted races. To elucidate the current evolutionary and taxonomic status of the greenbug and its biotypes, two nuclear genes and introns were sequenced; cytochrome c (CytC) and elongation factor 1-α (EF1-α). Phylogenetic analysis of CytC sequences were in complete agreement with COI sequences and demonstrated three distinct evolutionary lineages in S. graminum. EF1-α DNA sequences were in partial agreement with COI and CytC sequences, and demonstrated two distinct evolutionary lineages. Host-adapted races in greenbug are sympatric and appear reproductively isolated. Agricultural biotypes in S. graminum likely arose by genetic recombination via meiosis during sexual reproduction within host-races. The 1968 greenbug outbreak on sorghum was the result of the introduction of a host race adapted to sorghum, and not selection by host resistance genes in crops.     

褐飞虱致害性变异机制研究进展

褐飞虱Nilaparvata lugens Stal是危害水稻Oryza sativa L.的毁灭性害虫。种植抗虫水稻品种可以控制褐飞虱危害,技术手段绿色、经济且可持续。但是,褐飞虱致害性变异速度快且程度高,常导致抗虫水稻品种使用年限缩短。目前,针对褐飞虱致害性个体表型及分子标记、产生原因与机制、功能基因研究等已开展了大量研究。本文围绕褐飞虱致害性变异产生的遗传基础、分子标记、变异的主动机制和被动机制等方面进行综述,并对该领域未来方向进行展望。为更好地利用抗虫品种控制虫害,做好害虫的致害性监测及制定防治策略提供参考。     

mtCOI PCR-RFLP技术鉴别中国入侵型和土著型烟粉虱种群的有效性分析

烟粉虱Bemisia tabaci (Gennadius)是世界范围内最重要的入侵生物之一,准确地鉴别烟粉虱入侵生物型和土著生物型具有十分重要的现实意义。mtCOI PCR-RFLP技术具有快速、高效的特点,是当前应用最广泛的烟粉虱生物型鉴定技术,但是,不同限制性内切酶为基础的mtCOI PCR-RFLP技术在鉴定我国烟粉虱种群中的有效性仍不明了。本文比较了已报导的5种mtCOI PCR-RFLP技术在鉴别中国烟粉虱种群入侵生物型和土著生物型(B型、Q型,ZHJ1型、ZHJ2型、ZHJ3型)的有效性。结果表明,内切酶AluI不能区分B型和ZHJ2型烟粉虱;内切酶TaqI不能准确区分ZHJ3型和Q型烟粉虱个体;而内切酶VspI不仅不能准确区分ZHJ1型和Q型烟粉虱个体,也不能准确区分B型和ZHJ2型烟粉虱;内切酶MseI和Tru9I则不能有效鉴别上述5种烟粉虱生物型,因此不适宜推广使用。     

不同作物田烟粉虱发生的时空动态

2008～2009年连续2年系统调查了番茄、茄子、棉花、大豆、玉米等寄主植物上烟粉虱种群发生的时间与空间动态。结果表明：不同寄主植物上的烟粉虱成虫及其伪蛹数量有显著性差异,其密度大小依次为：茄子>棉花>番茄>大豆>玉米。其中,在玉米上除了发现极少量的成虫逗留外,没有发现烟粉虱的卵及若虫。在发生的时间序列上,烟粉虱成虫及伪蛹的数量呈现为先逐渐上升后又下降的变化过程,发生高峰期集中在8月5日到8月31日,9月初以后烟粉虱数量慢慢减少。在空间分布上,表现为烟粉虱成虫喜食寄主的上部叶片。统计分析显示,寄主对烟粉虱成虫和伪蛹的数量的影响极显著,而年份对其数量的影响没有显著差异。由此得出的烟粉虱发生和达到高峰的时间,可为烟粉虱预测预报和区域性综合治理提供重要理论依据。     

Microsatellite variability in the entomopathogenic fungus Paecilomyces fumosoroseus: genetic diversity and population structure

The hyphomycete Paecilomyces fumosoroseus (Pfr) is a geographically widespread fungus capable of infecting various insect hosts. The fungus has been used for the biological control of several important insect pests of agriculture. However knowledge of the fungus' genetic diversity and population structure is required for its sustainable use as a biological control agent. We investigated length and sequence polymorphisms of nine microsatellite loci for 33 Pfr accessions sampled from various host species and geographical locations, and our results reveal complex mutational processes for these molecular markers. Only Pfr isolates from Bemisia tabaci were amplified successfully, indicating the existence of Pfr genotypes specifically associated with B. tabaci. Genetic relationships among the 25 Pfr isolates from B. tabaci were inferred from allelic variability data at eight microsatellite loci that were polymorphic and subsequently from sequence data from the flanking regions of three selected loci. Maximum parsimony and neighbor joining analyses partitioned Pfr genetic diversity in two major lineages. One lineage included genotypes from the B-biotype of B. tabaci distributed across the Americas and was strongly supported in both analyses. Another lineage was distributed across Asia and consisted of four distinct clusters. Allele size homoplasy was found at the three microsatellite loci. We obtained better discrimination and resolution of the relationships among isolates with sequence data, although not all isolates could be typed. Thus sequencing of microsatellite flanking regions and repeats is a promising approach for the identification of Pfr isolates that specifically infect certain B. tabaci biotypes and phylogeographic studies.     

Symbiont diversity and non-random hybridization among indigenous (Ms) and invasive (B) biotypes of Bemisia tabaci

The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is a worldwide pest and a vector of numerous plant viruses. B. tabaci is composed of dozens of morphologically indistinguishable biotypes and its taxonomic status is still controversial. This phloem-feeder harbours the primary symbiont Portiera aleyrodidarum and potentially six secondary symbionts: Cardinium, Arsenophonus, Hamiltonella, Rickettsia, Wolbachia and Fritschea. In the southwest Indian Ocean, La Réunion hosts two biotypes of this species: B (invasive) and Ms (indigenous). A multiplex PCR was developed to study the symbiont community of B. tabaci on La Réunion. Symbiont community prevalence and composition, host mitochondrial and nuclear genetic diversity, as well as host plant and localization, were described on field populations of La Réunion for B and Ms B. tabaci biotypes and their hybrids. A clear association between symbiotypes and biotypes was shown. Cardinium, Arsenophonus and Rickettsia were found in the Ms biotype (73.6%, 64.2% and 3.3%, respectively). Hamiltonella (exclusively) and Rickettsia were found in the B biotype (78% and 91.2%, respectively). Hybrids harboured all symbiotypes found in Ms and B populations, but with a higher prevalence of Ms symbiotypes than expected under random hybridization. An unexpected majority was Cardinium mono-infected (65.6%), and a striking minority (9%) harboured Cardinium/Arsenophonus. In the hybrids only, genetic diversity was linked to symbiotype. Among the hybrids, significant links were found between symbiotypes and: (i) mitochondrial COI sequences, i.e. maternal origin; and (ii) alleles of nuclear microsatellite loci, specific to either Ms or B parental biotype. Taken together, our results suggest that Cardinium and/or Arsenophonus may manipulate the reproduction of indigenous (Ms) with invasive (B) biotypes of Bemisia tabaci.     

The root-knot nematode resistance gene Mi-1.2 of tomato is responsible for resistance against the whitefly Bemisia tabaci

The tomato gene Mi-1.2 confers resistance against root-knot nematodes and some isolates of potato aphid. Resistance to the whitefly Bemisia tabaci previously has been observed in Mi-bearing commercial tomato cultivars, suggesting that Mi, or a closely linked gene, is responsible for the resistance. The response of two biotypes of B. tabaci to tomato carrying the cloned Mi was compared with that of the isogenic untransformed tomato line Moneymaker. Our results indicate that Mi-1.2 is responsible for the resistance in tomato plants to both B- and Q- biotypes. Mi-1.2 is unique among characterized resistance genes in its activity against three very different organisms (root-knot nematodes, aphids, and whiteflies). These pests are among the most important on tomato crops worldwide, making Mi a valuable resource in integrated pest management programs.