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1.
北京地区地黄花叶病病原的分子鉴定   总被引：1，自引：0，他引：1  
为明确北京地区发生的地黄花叶病的病原,在进行生物学接种分离纯化的基础上利用RT-PCR方法对其进行了分子鉴定。通过接种指示植物和进行单斑分离,获得了病毒的纯分离物。经RT-PCR和序列测定及分析,有明显花叶症状的北京地黄样品受黄瓜花叶病毒Cucumber mosaic virus(CMV)和蚕豆萎蔫病毒2Broad bean wilt virus2(BBWV2)复合侵染。为进一步明确BBWV2地黄分离物(BBWV2-Rg)的分类地位,克隆了BBWV2-Rg RNA2多聚蛋白基因,并进行了序列测定和分析,结果表明该多聚蛋白基因由3 195个核苷酸组成,编码1 064个氨基酸。经序列比对分析,BBWV2-Rg编码的外壳蛋白大亚基LCP基因和小亚基SCP基因核苷酸序列与已发表的BBWV2其它株系相应基因核苷酸序列的同源性分别为78.69%~89.30%和76.99%~90.52%,氨基酸序列同源性分别为91.29%~97.51%和87.82%~96.45%。  相似文献   

2.
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3.
 本研究采用PCR点突变的方法,对豇豆退绿斑驳病毒(CCMV) RNA3的cDNA克隆进行突变,突变体TP7是在外壳蛋白基因之前突变形成一个独特的Sal I酶切点;TP8是在3a基因之前突变形成一个独特的Bam H I酶切点;AG 1是在外壳蛋白基因之后突变形成一个独特的Not I酶切点。TP7、TP8、AG1体外转录产物分别与CCMV RNA1、RNA2的c DNA克隆的体外转录产物混和后接种豇豆,结果表明,接种后第6 d TP7植株首先表现出症状,9d后TP8、AG1和野生型CCMV接种的植株表现出症状,TP7的症状发展最快。
采用TP7、TP8、AG1接种20 d的毒源植株,按TP7+TP8、TP7+AG1、TP8+AG1等量混合汁液接种豇豆,接种20 d,通过RT-PCR分析接种植物,在TP7+TP8和TP7+AG1混合侵染中,TP7在混合侵染中占优势,在TP8+AG1的混合侵染中,TP8和AG1的种群十分接近。  相似文献   

4.
 利用草莓镶脉病毒(Strawberry vein banding virus, SVBV)全长克隆pSVBV-E3构建SVBV侵染性克隆。pSVBV-E3经限制性内切酶酶切分别获得0.5-mer SVBV和1.0-mer SVBV,依次正向插入植物表达载体pBINPLUS,成功构建侵染性克隆重组质粒pBIN-1.5SVBV。pBIN-1.5SVBV转化农杆菌,分别接种森林草莓(Fragaria vesca)和4种烟草属植物(Nico-tiana spp.)验证其侵染性。结果表明,SVBV侵染性克隆接种森林草莓8周后发病,表现出典型的叶脉镶边黄化症状,PCR法可以从显症森林草莓中检测出SVBV cp基因,Southern blot法可以检测出SVBV基因组。而接种4种烟草属植物8周后未观察到发病症状,PCR法也未检测出SVBV cp基因。构建的SVBV侵染性克隆经接种验证能够侵染森林草莓,为进一步研究SVBV侵染森林草莓的致病机制奠定了基础。  相似文献   

5.
小西葫芦黄花叶病毒外壳蛋白基因的克隆及序列分析   总被引：8，自引：2，他引：8  
 以小西葫芦黄花叶病毒(Zucchini yellow mosaic virus,ZYMV)的中国分离物(CH-87)接种发病的叶片中提取的总RNA为模板,经RT-PCR扩增获得ZYMV CP基因,将其克隆到pUCm-T质粒上进行序列分析。结果表明该CP基因由837个核苷酸组成,编码279个氨基酸。与已发表序列相比较,该CP基因与国际上已报道的4个基因型不同,应属于新的基因型,暂命名为基因型Ⅴ。  相似文献   

6.
早春西瓜是云南热区的特色水果,近年来病毒病发生危害日益严重。为明确侵染早春西瓜的主要病毒,本研究采集了云南省西双版纳州勐海县的早春西瓜植株与果实病毒病样品,应用透射电子显微镜制样观察、间接酶联免疫吸附测定(ID-ELISA)和RT-PCR扩增克隆与测序分析进行检测鉴定。结果表明：侵染早春西瓜的病毒为西瓜银色斑驳病毒(WSMoV)和黄瓜花叶病毒(CMV);ID-ELISA对叶部样品WSMoV和CMV的检出率分别为70%和20%,复合侵染率为15%,RT-PCR对这两种病毒的检出率分别为100%和65%,复合侵染率为65%;并且,实验对发病果实种子进行RT-PCR扩增克隆和测序分析发现上述2种病毒复合侵染率达100%;系统发育树分析表明,云南西瓜WSMoV分离株21YV-40(GenBank登录号：OP617563)、21YV-43(GenBank登录号：OP867047)与云南分离株Banna-2011(GenBank登录号：KM242056)相似性最高,达到99.00%,云南西瓜CMV分离株CMVYN40(GenBank登录号：OP617565)、CMVYN46(GenBank登录号：...  相似文献   

7.
侵染性克隆是研究植物病毒的基础。黄瓜花叶病毒是目前最重要的植物病毒之一。本文以黄瓜花叶病毒M株系为材料来构建病毒的侵染性克隆。由于RNA1的c DNA对多数克隆菌株有毒性,因而采取了分段克隆的方法来构建RNA1的侵染性c DNA克隆,并进一步通过假重组技术来研究病毒的致病因子。结果表明,采用分段克隆的方法成功获得了CMV-M RNA1的侵染性克隆;M株系侵染烟草引起的黄白化症状与病毒的RNA3有直接相关性。  相似文献   

8.
 用RT-PCR扩增黄瓜花叶病毒M株系（CMV-M）全长基因组cDNA,成功构建CMV-M RNA2和RNA3侵染性克隆后,与CMV-Fny基因组RNA交换得到3个假重组型病毒 （F1M2F3、F1F2M3、F1M2M3）。用F1M2F3、F1F2M3、F1M2M3分别侵染白肋烟,产生坏死环斑、轻微绿斑驳、明脉、黄白化和叶尖线性化等症状。根据假重组型病毒和野生型病毒的表观症状,分析引起各种症状的关键因子,初步判定：CP基因是诱导花叶症状的关键因子,CMV-Fny RNA2是诱导叶尖线性化的关键因子,CMV-M RNA2是诱导叶尖坏死斑关键因子。实时荧光定量PCR结果显示：野生株CMV-M、CMV-Fny和假重组体F1M2F3、F1F2M3、F1M2M3侵染烟草后引起的症状差异与病毒基因组RNA累积没有直接关系。  相似文献   

9.
携带eGFP的ZYMV侵染性克隆的构建及其侵染性   总被引：1，自引：1，他引：0  
 小西葫芦黄花叶病毒(zucchini yellow mosaic virus,ZYMV)是瓜类作物主要病毒之一,严重威胁瓜类产业的可持续发展。本研究在ZYMV 甜瓜分离物CH-87侵染性克隆基础上,利用同源重组策略在NIb和CP编码序列之间插入了eGFP,命名为pXT1-ZYMV-eGFP。将pXT1-ZYMV-eGFP转化农杆菌并接种西瓜和甜瓜,结果发现pXT1-ZYMV-eGFP可以系统侵染西瓜和甜瓜,引起典型的花叶症状,在紫外灯下发病植株呈现绿色荧光。经摩擦接种证实,该克隆接种后所产生的病毒子代可以稳定的传播繁殖。研究表明携带eGFP的ZYMV侵染性克隆成功构建,可用于该病毒致病性及病毒与寄主互作的相关研究。  相似文献   

10.
 对一株从美人蕉上分离到的CMV(Cah1-CMV)进行了全长克隆、全序列分析及寄主生物学研究。结果显示:其RNA1全长为3 356 nt,编码993个aa的1a蛋白;RNA2全长为3 045 nt,编码843 aa的2a蛋白和111 aa的2b蛋白;RNA3全长为2 220 nt,编码279 aa的3a蛋白和218 aa的CP蛋白。系统进化树分析显示:Cah1-CMV是CMV亚组IB株系。但是,该株系可以通过汁液摩擦接种侵染烟草(Nicotiana tabacum)、心叶烟(N.glutinosa)和番茄(Lycopersivon esculentum)鉴别寄主,可引起心叶烟顶端坏死,而在其他茄科寄主上均为典型花叶。将Cah1-CMV的2b替换到Fny-CMV中,产生FCah12b-CMV重组体,分析其在心叶烟上的致病性。结果显示:侵染早期,FCah12b-CMV引起心叶烟顶端叶黄褐坏死,与其母本病毒Cah1-CMV的症状相似,而非Fny-CMV症状;侵染后期,FCah12b-CMV并不引起植株系统性坏死。Northern blot-ting结果显示:Cah1-CMV、FCah12b-CMV和Fny-CMV在系统叶中的积累水平不存在明显差异。以上结果说明Cah1-CMV的2b基因在Cah1-CMV致病过程中具有重要功能,但并不是整株症状的决定因子;致病性差异与其基因组RNA在寄主体内的积累水平并不呈正相关性。  相似文献   

11.
Fifteen species of dermestid beetles were recorded at ‘Evolution Canyon’ (EC), Lower Nahal Oren, Mt. Carmel, Israel. They represent ~35% of known Israeli dermestid species. The following three species were recorded for the first time in Israel:Trogoderma svriaca Dalla Torre, 1911;Ctesias svriaca Ganglbauer, 1904; andAnthrenus (s.str.) jordaniens Pic, 1934. Adults of 13 species were collected on the more solar radiated, warmer and climatically more fluctuating south-facing slope (SFS); ten species were collected on the opposite, north-facing slope (NFS), which was cooler and climatically more stable. The abundance of adult dermestid beetles was 1.9 times higher on the SFS than on the NFS (86 and 47, respectively). Species richness and abundance distribution at EC (three collecting stations on each slope and one at the valley bottom) were significantly negatively correlated with the plant cover that consisted of trees and bushes (Spearmanr s ,P=0.007 and 0.039, respectively) and perennials (Spearmanr s ,P=0.039 and 0.077, respectively), indicating that non-woody plants were preferred by adult dermestid beetles.  相似文献   

12.
Recent data on the epidemiology of the common mycotoxigenic species of Fusarium, Alternaria, Aspergillus and Penicillium in infected or colonized plants, and in stored or processed plant products from the Mediterranean area are reviewed. Emphasis is placed on the toxigenicity of the causal fungal species and the natural occurrence of well known mycotoxins (aflatoxins, ochratoxins, fumonisins, trichothecenes, zearalenone, patulin, Alternaria-toxins and moniliformin), as well as some more recently described compounds (fusaproliferin, beauvericin) whose toxigenic potential is not yet well understood. Several Fusarium species reported from throughout the Mediterranean area are responsible of the formation of mycotoxins in infected plants and in plant products, including: Fusarium graminearum, F. culmorum, F. cerealis, F. avenaceum, F. sporotrichioides and F. poae, which produce deoxynivalenol, nivalenol, fusarenone, zearalenone, moniliformin, and T-2 toxin derivatives in wheat and other small grains affected by head blight or scab, and in maize affected by red ear rot. Moreover, strains of F. verticillioides, F. proliferatum, and F. subglutinans, that form fumonisins, beauvericin, fusaproliferin, and moniliformin, are commonly associated with maize affected by ear rot. Fumonisins, were also associated with Fusarium crown and root rot of asparagus and Fusarium endosepsis of figs, caused primarily by F. proliferatum. Toxigenic A. alternata strains and associated tenuazonic acid and alternariols were commonly found in black mould of tomato, black rot of olive and citrus, black point of small cereals, and black mould of several vegetables. Toxigenic strains of A. carbonarius and ochratoxin A were often found associated with black rot of grapes, whereas toxigenic strains of A. flavus and/or P. verrucosum, forming aflatoxins and ochratoxin A, respectively, were found in moulded plant products from small cereals, peanuts, figs, pea, oilseed rape, sunflower seeds, sesame seeds, pistachios, and almonds. Finally, toxigenic strains of P. expansum and patulin were frequently found in apple, pear and other fresh fruits affected by blue mould rot, as well as in derived juices and jams.  相似文献   

13.
Molecular diagnostic techniques have been developed to differentiate the Ascochyta pathogens that infect cool season food and feed legumes, as well as to improve the sensitivity of detecting latent infection in plant tissues. A seed sampling technique was developed to detect a 1% level of infection by Ascochyta rabiei in commercial chickpea seed. The Ascochyta pathogens were shown to be genetically diverse in countries where the pathogen and host have coexisted for a long time. However, where the pathogen was recently introduced, such as A. rabiei to Australia, the level of diversity remained relatively low, even as the pathogen spread to all chickpea-growing areas. Pathogenic variability of A. rabiei and Ascochyta pinodes pathogens in chickpea and field pea respectively, appears to be quantitative, where measures of disease severity were based on aggressiveness (quantitative level of infection) rather than on true qualitative virulence. In contrast, qualitative differences in pathogenicity in lentil and faba bean genotypes indicated the existence of pathotypes of Ascochyta lentis and Ascochyta fabae. Therefore, reports of pathotype discrimination based on quantitative differences in pathogenicity in a set of specific genotypes is questionable for several of the ascochyta-legume pathosystems such as A. rabiei and A. pinodes. This is not surprising since host resistance to these pathogens has been reported to be mainly quantitative, making it difficult for the pathogen to overcome specific resistance genes and form pathotypes. For robust pathogenicity assessment, there needs to be consistency in selection of differential host genotypes, screening conditions and disease evaluation techniques for each of the Ascochyta sp. in legume-growing countries throughout the world. Nevertheless, knowledge of pathotype diversity and aggressiveness within populations is important in the selection of resistant genotypes.  相似文献   

14.
We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.  相似文献   

15.
The genera ofMicrogaster Latreille 1804 andHygroplitis Thomson 1895 from China are presented systematically in this paper. Thirty-two species ofMicrogaster and three species ofHygroplitis are known in China. Diagnosis, character variation, distribution and host of each species among the two genera are presented, including its host and distribution. Keys to the species ofMicrogaster andHygroplitis are given. http://www.phytoparasitica.org posting Dec. 19, 2006.  相似文献   

16.
Plant Viruses Transmitted by Whiteflies   总被引：18，自引：0，他引：18  
One-hundred and fourteen virus species are transmitted by whiteflies (family Aleyrodidae). Bemisia tabaci transmits 111 of these species while Trialeurodes vaporariorum and T. abutilonia transmit three species each. B. tabaci and T. vaporariorum are present in the European–Mediterranean region, though the former is restricted in its distribution. Of the whitefly-transmitted virus species, 90% belong to the Begomovirus genus, 6% to the Crinivirus genus and the remaining 4% are in the Closterovirus, Ipomovirus or Carlavirus genera. Other named, whitefly-transmitted viruses that have not yet been ranked as species are also documented. The names, abbreviations and synonyms of the whitefly-transmitted viruses are presented in tabulated form together with details of their whitefly vectors, natural hosts and distribution. Entries are also annotated with references. Whitefly-transmitted viruses affecting plants in the European–Mediterranean region have been highlighted in the text.  相似文献   

17.
《干旱区科学》2014,(6):782-782
正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad  相似文献   

18.
Solacol®, a formulation of the antibiotic validamycin, at 0.33% in 2% malt extract agar, reduced the spread of fungi on dilution plates drastically and allowed twice as much incubation time before subculturing; this resulted in an elevated number of species isolated. Using pure cultures of 62 common soil fungi, it was shown that all fast-growing species (exceptPythium ultimum) were efficiently inhibited but not completely suppressed. Inhibition was comparable to that by 0.5% oxgall, though, while this substance completely suppressed several species, Solacol very strongly inhibited onlyGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum andRhizoctonia solani. In a further experiment each separate constituent of Solacol was tested against 22 fungi at equivalent concentrations. Validamycin strongly inhibitedChaetomium globosum and two Basidiomycetes, though hardly more than the non-ionic detergent which mainly inhibited the other fungi. A few species were, however, more inhibited by Solacol than by the detergent alone. Solacol at 0.33% is a suitable aid in dilution plating of soil fungi, by increasing the number of colonies and species observed.Samenvatting Solacol®, een formulering van het antibioticum validamycine, remde de groei van schimmels in verdunningsplaten met een concentratie van 0.33% in 2% moutagar en maakte het mogelijk de periode tot afenten met een factor 2 te verlengen; daardoor was het aantal geïsoleerde soorten duidelijk toegenomen. Met reincultures van 62 algemene grondschimmelsoorten werd aangetoond, dat alle snelgroeiende soorten (met uitzondering vanPythium ultimum) voldoende geremd, maar niet volkomen onderdrukt werden. Het remmingspercentage was vergelijkbaar met dat van 0.5% ossegal, hoewel dit laatste sommige soorten volkomen onderdrukte; Solacol remde alleenGaeumannomyces graminis, Gerlachia nivalis, Harzia acremonioides, Verticillium biguttatum enRhizoctonia solani zeer sterk. In een volgend experiment werden de componenten van Solacol t.o.v. 22 fungi apart getoetst in concentraties equivalent aan 0.33% Solacol. Validamycine remde alleenChaetomium globosum en twee basidiomyceten behoorlijk, maar nauwelijks meer dan de niet-ionische uitvloeier, die in hoofdzaak de overige remeffecten veroorzaakte. Enkele soorten werden echter door het complete Solacol veel sterker geremd dan door de uitvloeier alleen. Solacol in een verdunning van 0,33% wordt aanbevolen bij verdunningsplaten voor het isoleren van grondschimmels ten einde het aantal kolonies en soorten te verhogen.  相似文献   

19.
Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.  相似文献   

20.
A collection of 38 PVY isolates from seed potato batches, originating from several Western European countries, was characterized by using current biological, serological and molecular tools differentiating PVY strains and groups. The correlation between the three kinds of tests was good but not absolute. No single serological or PCR method was able to discriminate among the five isolate groups found. Twenty-nine isolates belonged to the PVYN strain and six to the PVYO strain. No PVYC was found. Two other isolates reacted serologically like PVYO, but were unable to elicit a hypersensitive response from the Nytbr gene and probably represent the PVYZ group. At the molecular level, these two isolates showed a combination of both PVYO and PVYN and could be recombinants of these strains. Another isolate reacted serologically like PVYO, but induced vein necrosis in tobacco, like PVYN-Wilga. Some PVYN isolates caused tuber ring necrosis in glasshouse conditions. These might belong to the PVYNTN group. The PVYNTN, PVYN-Wilga and PVYZ groups probably represent pathotypes within strains PVYN and PVYO, respectively. The present study also confirms previous reports showing a high genetic variation at the 5 end within the PVYN strain.  相似文献   

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