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J. W. Roenhorst N. Boonham S. Winter W. Menzel R. A. A. van der Vlugt 《EPPO Bulletin》2013,43(2):238-243
The availability of characterised reference isolates of plant pathogens is of crucial importance for research and diagnostic laboratories. The Q‐bank Plant Viruses and Viroids database contains data and information on plant viruses and viroids, with the unique feature that it is linked to specimens present in publicly available physical collections. The Q‐bank database aims to share data and information on the virus and viroid species and their availability between research and diagnostic laboratories. Currently the database focuses on regulated virus species. In future more plant viruses and viroids will be included to provide a comprehensive data and information system. The curators invite virologists worldwide to participate in this international initiative by making their data and isolates available via Q‐bank ( http://www.q-bank.eu ). 相似文献
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Q‐collect: results of a European Union project to improve the status of reference collections important for plant health 
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下载免费PDF全文 P. Bonants J.‐C. Streito J. Elphinstone P. Pottier V. Robert S. Bluemel M. van der Blom P. Gentit P. de Vos F. Petter 《EPPO Bulletin》2016,46(2):348-358
The ability of National Plant Protection Organizations (NPPOs) and their affiliated laboratories to quickly and reliably detect and identify organisms is critical for the effective performance of phytosanitary measures. Plant pest diagnostics is also essential to support the phytosanitary certification of consignments of plants and plant products exported from the EU. Access to reference material has been identified as a limitation on the ability of laboratories to develop and validate diagnostic tests and ensure the reliability of diagnostics. The EU FP7 Q‐collect project worked to establish the state of the art of current phytosanitary collections, to identify gaps and propose minimum quality standards, to facilitate access to specimens and to design and build networks of reference collections. The main results of the project are presented in this paper. 相似文献
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目前, 我国梅树上的病毒种类及发生情况仍不完全清楚。本研究从北京、武汉、南京和无锡的梅园中采集了64份疑似感染病毒的叶片样品, 通过RT-PCR和斑点杂交, 对7种病毒和2种类病毒进行了检测。共检测到6种病毒和1种类病毒。其中, 李属坏死环斑病毒(prunus necrotic ringspot virus, PNRSV)和桃潜隐花叶类病毒(peach latent mosaic viroid, PLMVd)为我国梅树上的首次检出。PNRSV、亚洲李属病毒2号(Asian prunus virus 2, APV2)、桃叶痘伴随病毒(peach leaf pitting-associated virus, PLPaV)的检出率高于30%。综合考虑病毒的分布及检出率, PLPaV、APV2、PNRSV和李树皮坏死茎痘伴随病毒(plum bark necrosis stem pitting-associated virus, PBNSPaV)是武汉、南京和无锡梅树上的主要病毒。此外, 通过克隆和测序, 获得了PLMVd和梅树病毒A(mume virus A, MuVA)的基因组, PLPaV的RNA1组分和PNRSV外壳蛋白(CP)基因序列。序列比较分析显示, 我国PLMVd梅分离物和PNRSV梅分离物与我国桃分离物亲缘关系最近, 表明PLMVd和PNRSV可能在梅和桃树间交互侵染;我国MuVA梅分离物序列与日本梅分离物序列的相似性高达98.56%;PLPaV梅分离物与我国桃分离物之间序列变异较大。上述结果不仅进一步明确了我国梅树上的病毒及类病毒种类和分布情况, 而且有助于深入了解它们的流行与传播。 相似文献
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Production of anti-virus,viroid plants by genetic manipulations 总被引：1，自引：0，他引：1
Ishida I Tukahara M Yoshioka M Ogawa T Kakitani M Toguri T 《Pest management science》2002,58(11):1132-1136
Many pathogenic plant viruses are RNA viruses, which initiate production of double-stranded RNA intermediates when they replicate in host plant cells. Introduction of double-stranded RNA-specific ribonucleases such as the Schizosaccharomyces pombe derived pac I protein and animal cell derived interferon-induced 2',5'-oligoadenylate synthetase (2-5 Aase)/ribonuclease L (RNase L) system into various plants may make plants resistant to various pathogenic viruses and viroids. We have demonstrated that pac I and 2-5 Aase/RNase L transgenic tobacco plants are resistant to various viruses including tobacco mosaic virus, cucumber mosaic virus and potato virus Y. In addition, pac I transgenic potato plants are resistant to potato spindle tuber viroid. Using Agrobacterium-mediated transformation, we have established a transformation system for chrysanthemum plants and have recently developed pac I transgenic chrysanthemum (Dendranthema grandiflora cv Reagan) resistant to chrysanthemum stunt viroid and have grown them in isolated fields for an evaluation of their effects. 相似文献
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Many laboratories maintain historical collections of preserved plant virus isolates that store a wealth of untapped data, including original type isolates, studied in the pre-sequencing era. Currently, many recently recognized virus species exist with no supporting reference sequences. Also, many virus sequences appear new when compared to available sequences, but, on sequencing pre-sequencing era isolates, they may coincide. Such linkages allow access to data from previously determined biological and other parameters from pre-sequencing era studies. These linkages are increasingly being found using high-throughput sequencing, helping clarify virus taxonomy and improving understanding of virus ecology and evolution. Thus, mistakes can be avoided in naming viruses and in combining or separating them, as well as enabling identification of unknown viruses preserved long ago. With well-established viruses, success in dating and other evolutionary studies, and discovery of changes in regional virus populations, both depend upon comparisons between recent and old isolate sequences covering the greatest possible time periods. Such studies help reveal the extent that human activities have influenced virus evolution and changed virus populations on a global scale. Sequencing virus genomes from herbarium specimens, archaeological specimens, or living plant collections can provide complementary data. By bringing context to newly detected viruses and supporting plant pest risk analyses, linking new virus discoveries to previously generated disease symptom, host range, virus transmission, and geographical distribution data has important implications for plant health regulation. Also, historical isolates can provide an invaluable resource facilitating biosecurity investigations involving virus introductions, entry pathways, and baseline surveillance. 相似文献
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The work described here formed part of the EU SMT DIAGPRO project, to develop diagnostic protocols for 18 regulated pests. The Potato spindle tuber pospiviroid (PSTVd) protocol was developed primarily for testing in vitro‐ and glasshouse‐grown potato plants for the purposes of post‐entry quarantine and the production of pathogen‐tested nuclear stock. After a performance audit of methods used by 12 laboratories in Europe and America by ring testing, four methods were chosen for multilaboratory validation. For most laboratories, the detection limits were 10–20 mg of PSTVd‐infective tissue for R‐PAGE; 0.25–0.5 mg for DIG‐probe; 0.062 mg for RT‐PCR; and 0.0155 mg for TaqMan (this was the lowest weight of infective tissue tested). Some laboratories were able to extend the detection limit to 0.0155 mg for DIG‐probe and RT‐PCR. The DIG‐probe and R‐PAGE are recommended as primary detection methods, with confirmation of viroid presence by any of the four validated detection methods. Specific diagnosis requires the viroid to be sequenced. Other methods may be used for primary detection, providing that they preferably detect all PSTVd isolates and other Pospiviroids that have the potential to infect potato, and detect viroid in at least 1/10 of the tissue weight normally tested per plant. 相似文献
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Field surveys were carried out in the main stonefruit-growing areas of Jordan to assess the sanitary status of varietal collections, mother plant blocks and commercial orchards. The presence of virus and virus-like diseases was determined by ELISA, sap transmission to herbaceous hosts, graft transmission to Prunus persica cv. GF 305 and P. serrulata cv. Kwanzan, and molecular hybridization tests. A total of 1312 samples was tested by ELISA (531 peach, 361 plum, 218 apricot, 135 almond and 67 cherry trees). The overall mean level of infection was about 14%, indicating an acceptable sanitary status as a whole, considering that no sanitary selection has ever been carried out in Jordan. The infection level of different species was: peach (18%), cherry (15%), almond (14%), apricot (11%) and plum (10%). The following viruses and viroids were identified: Plum pox potyvirus (PPV), Prunus necrotic ringspot ilarvirus (PNRSV), Prune dwarf ilarvirus (PDV), Apple mosaic ilarvirus (ApMV), Apple chlorotic leaf spot trichovirus (ACLSV), Hop stunt viroid (HSVd) and Peach latent mosaic viroid (PLMVd). Most of these agents (ApMV, ACLSV, PLMVd and HSVd) are reported for the first time from Jordan. 相似文献
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ICTV最新十五级分类阶元病毒分类系统中的植物病毒 总被引：1，自引：0，他引：1
本文报告了国际病毒分类委员会(ICTV)于2020年3月批准的最新2019病毒分类系统,全面采用了十五级分类阶元,分别为:域、亚域、界、亚界、门、亚门、纲、亚纲、目、亚目、科、亚科、属、亚属、种。寄主为植物的病毒包括了植物病毒和亚病毒感染因子(类病毒、卫星病毒和卫星核酸)。植物病毒共有1 608种,涉及2个域、3个界、8个门、13个纲、16个目、31个科、8个亚科、132个属、3个亚属。亚病毒感染因子包括33种类病毒,涉及2个科、8个属;6种卫星病毒,涉及4个属;142种卫星核酸,涉及2个科、2个亚科和13个属。 相似文献
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The fast growth of the human population forces us to produce more food, but higher crop production also leads to the fast spread of diseases. Plant pathology deploys a wide range of methods that do not provide an adequate solution to all disease losses. In the case of viroids, therapeutic means of control are not available; therefore control strategies are more focused on the development of reliable detection methods to quickly exclude the infected plant material. Although viroids are the smallest and simplest plant pathogens, their identification and detection is not straightforward. Each viroid–host combination is specific, and for reliable identification, all steps from sampling to final detection must be performed accurately. In this review, several methods for viroid detection in various host plants are discussed, including their advantages and disadvantages. Even though relatively new molecular methods enable fast and sensitive detection of viroids, a combination of different methods gives the most reliable identification. Techniques based on nucleic acids may be the future for viroid detection but they still cannot replace biological indexing, which is usually essential in epidemiological and aetiological studies. 相似文献
11.
Suspension depletion approach for exemption of infected Solanum jasminoides cells from pospiviroids 下载免费PDF全文
下载免费PDF全文 I. Digel V. Wehlitz P. Kayser A. Figiel‐Lange R. Bassam F. von Rundstedt 《Plant pathology》2018,67(2):358-365
Despite numerous studies, viroid elimination from infected plants remains a very challenging task. This study introduces for the first time a novel ‘suspension depletion’ approach for exemption of Solanum jasminoides plants from viroids. The proposed method implies initial establishment of suspension cultures of the infected plant cells. The suspended cells were then physically treated (mild thermotherapy, 33 °C), which presumably delayed the replication of the viroid. The viroid concentration in the treated biomass was monitored weekly using pospiviroid‐specific PCR. After 10–12 weeks of continuous treatment, a sufficient decrease in viroid concentration was observed such that the infection became undetectable by PCR. The treated single cells then gave rise to microcolonies on a solid culture medium and the obtained viroid‐negative clones were further promoted to regenerate into viroid‐free plants. Three years of accumulated experimental data suggests feasibility, broad applicability, and good efficacy of the proposed approach. 相似文献
12.
DNA barcoding protocols for selected EU‐regulated arthropods, bacteria, fungi, nematodes and phytoplasmas were developed within the Quarantine organisms Barcoding of Life (QBOL) project financed by 7th framework program of the European Union. DNA barcodes generated with the developed protocols were stored in the Q‐bank database. An test performance study (TPS) was set up involving 14 participating laboratories to validate the use of the developed protocols as a diagnostic tool and to identify possible difficulties in the use of the protocols and Q‐bank. This paper describes the steps that were used to set up the TPS, to validate the protocols and to identify difficulties. TPS data shows that the developed tests are very robust and produce highly reproducible results. Participants managed to define good consensus sequences which allowed them to correctly identify their samples using Q‐bank in 78% of all cases. Q‐bank outperformed NCBI and BOLD in terms of diagnostic sensitivity and diagnostic specificity for all organism groups. Using general qualifiers, performance criteria and feedback from TPS participants, difficulties in the set‐up of the TPS, the use of the protocols and databases, and the proficiency of participants were identified/evaluated and recommendations for future work were made. The developed DNA barcoding protocols and Q‐bank have proven to be useful tools in support of the identification of selected EU‐regulated plant pests and pathogens on the desired taxonomical level. 相似文献
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Arizona 861-S1 citron ( Citrus media L.) infected with a severe exocortis isolate containing four citrus viroids was used as source of tissue for shoot-tip grafting in vitro. Out of 51 attempts, 25 successful grafts were obtained. Only 16 plants survived transplanting and of these 12 were viroid-free. The viroid profile of the other four plants showed fewer viroids than the original field source. The significance of these results, as compared with previous reports on the recovery of viroid-free plants, is discussed. The results show the usefulness of shoot-tip grafting in vitro as a tool to recover single viroid isolates from complex field sources. 相似文献
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In studies to identify genotypes resistant to infection with citrus viroids, Eremocitrus glauca and Microcitrus australis were selected because their evolution in their habitat in Australia and New Guinea may have led to the selection of unusual traits. The movement and accumulation of Citrus exocortis viroid (CEVd), Hop stunt viroid, Citrus bent leaf viroid, Citrus dwarfing viroid, Citrus bark cracking viroid and Citrus viroid V (CVd‐V) in self‐rooted as well as in graft‐ propagated E. glauca and M. australis plants was assessed by northern hybridization, RT‐PCR and by topworking to the sensitive selection 861‐S1 of Etrog citron. In both plant species the inoculated viroids were undetectable unless these plants were grafted to a susceptible Citrus partner, the rough lemon rootstock and/or the topworked Etrog citron, which acted as viroid sources. The results obtained indicate that M. australis and in particular E. glauca are poor viroid hosts in which viroid replication/accumulation does not occur or is extremely inefficient. However, viroid downward and upward movement to grafted Citrus partners in which viroid replication and accumulation occurs efficiently was not impaired. Eremocitrus glauca and M. australis showed differences regarding their properties as viroid hosts, but for both species CEVd seemed to have the lowest affinity among the viroid species tested and CVd‐V the highest. Even though E. glauca and M. australis do not appear to be truly resistant to viroid infection, they are interesting genotypes for further characterization of the mechanisms involved in viroid infection. 相似文献
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类病毒是已知最小的植物病原物,可侵染蔬菜、果树以及花卉等多种农作物,并对农业生产造成严重影响。目前,对感染类病毒的植株进行脱毒处理是一种有效的防控措施,本文针对果树、蔬菜和花卉上几种常见的类病毒,综述了茎尖培养、热处理结合茎尖培养、低温处理、超低温处理、化学处理及不含叶原基的顶端分生组织再生等植物类病毒的脱除技术,分析了不同方法的应用效果及所适合脱除的类病毒种类,同时展望了类病毒病害在未来植物病害防控中的重要地位,并提出综合考虑各种因素、制定合理方案、选用适宜方法的类病毒脱除建议。 相似文献
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ABSTRACT Citrus viroid (CVd) group II is comprised of hop stunt viroid (HSVd)-related variants of 295 to 302 nucleotides. Included in this group are the cachexia-inducing agents citrus cachexia viroid (or CVd-IIb), CVd-IIc, Ca-903, and Ca-909 as well as the non-cachexia-inducing variant CVd-IIa. The cachexia indexing hosts 'Parson's Special' mandarin and 'Orlando' tangelo as well as Citrus macrophylla responded with symptoms of gumming, discoloration, and stem pitting when infected by CVd-IIb, CVd-IIc, or Ca-903. However, 'Palestine' sweet lime, the indicator host used to describe the xyloporosis disease, displayed a distinctly different fine-pitting reaction and no discoloration or gumming when infected by the same viroids. Cachexia-inducing variants contain a number of nucleotide changes more similar to hop-type HSVd sequences than to the citrus-type HSVd sequences, as typified by CVd-IIa. The nucleotide sequence of CVd-IIc was identical to CVd group II isolates common to trees expressing xyloporosis. Experimental evidence indicates that either CVd-IIb or CVd-IIc can cause citrus diseases known as cachexia and xyloporosis and that the two disease designations reflect the distinct responses of different indexing hosts to the same viroids. 相似文献
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E. Choueiri C. Haddad N. Abou Ghanem-Sabanadzovic F. Jreijiri S. Issa A. T. Saad B. Di Terlizzi V. Savino 《EPPO Bulletin》2001,31(4):493-497
Field surveys were carried out in the main peach-growing areas of Lebanon to assess the presence and distribution of viruses and viroids in commercial orchards. Field inspections were made in spring and summer 2000 to observe symptoms of virus and viroid diseases respectively. In total, 950 trees in 95 commercial plantings from three different regions of Lebanon (Bekaa Valley, Mount Lebanon and north Lebanon) were surveyed and sampled. Immunoenzymatic tests (DAS-ELISA) were used to ascertain the presence of the following: Prunus necrotic ring spot ilarvirus (PNRSV), Prune dwarf ilarvirus (PDV), Apple mosaic ilarvirus (ApMV), Apple chlorotic leaf spot trichovirus (ACLSV), Plum pox potyvirus (PPV), Tomato ringspot nepovirus (ToRSV) and Strawberry latent ringspot nepovirus (SLRSV). Peach latent mosaic pelamoviroid (PLMVd) and Hop stunt hostuviroid (HSVd) were identified by molecular hybridization. About 25% of the tested samples were infected by one or more viruses. In particular, the prevailing virus was PNRSV (61.2% of infection), followed by ACLSV (27.1%), PDV (22.4%) and ApMV (2.1%). Mixed infections were about 13%. ToRSV, SLRSV and PPV were not found. HSVd was apparently absent, whereas PLMVd was identified in 34% of the samples examined. This viroid prevailed in certain areas of Mount Lebanon in both native and foreign cultivars. 相似文献