共查询到20条相似文献，搜索用时 46 毫秒
1.
Dilip K. Ghosh Sumit Bhose Krishanu Mukherjee Balaji Aglave A. J. Warghane Manali Motghare V. K. Baranwal Arun K. Dhar 《Phytoparasitica》2014,42(5):681-689
Citrus yellow mosaic badnavirus (CMBV) is a non-enveloped, bacilliform DNA virus and the etiologic agent of yellow mosaic disease of citrus in India. The disease was initially reported from the southern parts of India and has now spread to other parts of the country. It is a serious disease of sweet orange (Citrus sinensis) in southern India, where it causes significant yield losses. During a recent survey of citrus groves in the Nagpur region, central India, characteristic mosaic symptoms were observed in mandarin orange (Citrus reticulata) and sweet orange. Virus transmission studies, electron microscopy, PCR amplification and sequencing of cloned PCR products from samples showing mosaic symptoms confirmed the presence of a badnavirus. The CMBV–Nagpur isolate could be transmitted to the Rangpur lime (C. limonia) and acid lime (Citrus aurantifolia) by graft inoculation. Sequence analysis of a segment of ORF-III region and intergenic region (IR) of the viral genome revealed that CMBV–Nagpur isolate formed a distinct clade along with some previously reported isolates that are known to infect acid lime and Rangpur lime. CMBV isolates that infect citrus species other than the acid lime and Rangpur lime formed a second clade. Based on the transmission studies and phylogenetic analyses, it was concluded that at least two strains of CMBV exist in India currently. 相似文献
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为明确柑橘衰退病毒(citrus tristeza virus, CTV)和柑橘黄脉病毒(citrus yellow vein clearing virus, CYVCV)在广西柑橘上的发生?分布及其遗传变异情况, 于2020年至2021年对百色?北海?崇左?贵港?桂林?河池?贺州?来宾?柳州?南宁?梧州和玉林等12个柑橘产区进行了病毒病调查?采用RT-PCR对采集样品进行了病毒检测, 并基于病毒分离物外壳蛋白(coat protein, CP)基因的核苷酸序列进行比对分析, 构建系统发育树?结果表明:采集的737份柑橘样品中, CTV的检出率为20.62%, CYVCV检出率为18.32%, CTV的检出率略高于CYVCV?病毒复合侵染的现象在采集的柑橘样品中普遍存在, CTV和CYVCV复合侵染率高达34.50%?对RT-PCR产物测序共获得12个CTV分离物和6个CYVCV分离物的CP基因序列?遗传多样性分析发现, CTV和CYVCV的CP基因序列都较保守, CTV分离物的遗传进化与地理来源?寄主来源均没有明显相关性, 但CYVCV分离物的遗传进化与地理位置具有相关性, 而与寄主来源无明显相关性?上述研究结果可为深入了解CTV和CYVCV在广西的流行情况以及柑橘病毒病的检疫和防控提供参考? 相似文献
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Silvija Cerni Dijana Skoric Jelena Ruscic Mladen Krajacic Tatjana Papic Khaled Djelouah Gustavo Nolasco 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(4):701-706
Citrus tristeza virus (CTV) represents one of the major threats to citrus production worldwide. In the East Adriatic region, CTV symptoms are mostly
absent due to traditional citrus grafting on trifoliate orange (Poncirus trifoliata), a CTV-tolerant rootstock. Therefore, the virus has been continuously spreading by the propagation of infected material.
The genetic variability of CTV was studied on nineteen citrus samples, collected from orchards in the coastal region of Croatia,
Montenegro and Albania, that previously tested positive by ELISA and immunocapture RT-PCR. Single-strand conformation polymorphism
of the amplified coat protein gene demonstrated the presence of different CTV variants in each amplicon, while sequence analysis
of cloned CP gene variants confirmed their clustering into six out of the seven phylogenetic groups so far delineated. Four
of these groups include sequences of severe quick decline, seedling yellows and stem-pitting (SP) isolates, thought to be
found only rarely in the Mediterranean region. Regardless of the lack of symptoms in the field, CTV isolates from the East
Adriatic displayed high genetic variability and pathogenic potential, additionally confirmed by biological characterisation.
The high percentage of mixed infections suggest the potential for further diversification and a greater risk of severe variants
spreading into new areas. 相似文献
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6种柑橘类植物对柑橘衰退病毒分离株TR-L514变异的影响 总被引：2，自引：0，他引：2
柑橘衰退病毒(Citrus tristeza virus,CTV)存在复杂的株系分化现象,运用弱毒株交叉保护防治柑橘衰退病时需了解不同类型柑橘对CTV构成的影响。作者将CTV分离株TR-L514嫁接接种到6类柑橘植物上获得了18个亚分离株,并对这18个亚分离株和TR-L514进行了指示植物鉴定,p25基因的限制性片段长度多态性(RFLP)和单链构象多态性(SSCP)分析,p23基因的序列比较。结果表明,CTV株系对不同柑橘类植株的适应性存在差异。TR-L514嫁接到不同柑橘类植株其构成会发生变化,在甜橙上可以同时检测出p25//HinfⅠ RFLP第1和6组群,并具有比在其它4类柑橘上更为复杂的SSCP谱型构成,因此甜橙可能更适宜于CTV的增殖。TR-L514及18个亚分离株的p23基因序列差异可能与不同类柑橘植株的适应性有关。 相似文献
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Svetlana Fishman Ruth Marcus H. Talpaz M. Bar-Joseph Y. Oren R. Salomon M. Zohar 《Phytoparasitica》1983,11(1):39-49
Citrus tristeza virus (CTV) causes a most destructive citrus disease in many parts of the world, and indications of natural spread were found in Israel in 1970. The strategy for controlling the disease in Israel is based on the eradication of virus-infected trees, detected by test plants or immunological methods. Mathematical models for CTV infection and spread were developed and used to assess the cost-effectiveness of the eradication policy. It was concluded that the discovery-eradication program is economically justified and superior to allowing the disease to progress unchecked. 相似文献
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Photosynthetic and antioxidant responses of Mexican lime (Citrus aurantifolia) plants to Citrus tristeza virus infection 
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下载免费PDF全文 R. M. Pérez‐Clemente A. Montoliu V. Vives M. F. López‐Climent A. Gómez‐Cadenas 《Plant pathology》2015,64(1):16-24
The effect of Citrus tristeza virus (CTV) infection on photosynthetic activity and antioxidant metabolism was analysed in plants of the highly susceptible citrus genotype Mexican lime (Citrus aurantifolia). Two virus isolates differing in their virulence (the severe T318 and the mild T385) were used in the experiments. CTV infection caused a reduction in photosynthetic capacity in infected plants. This limitation was mainly due to a reduction in the carboxylative efficiency whereas the limitation of CO2 diffusion through the stoma had lower impact. The virus did not damage the antennae and did not reduce the efficiency of light harvesting complexes. Oxidative damage occurred in infected plants, as evidenced by the increase in malondialdehyde levels. Indeed, CTV infection caused an increase in ascorbate peroxidase activity in new shoots developed in infected plants during the 2 years of the experiment. Data suggest that the H2O2 removal machinery was not damaged as a result of stress but the defence mechanism was overwhelmed with time due to the continuing pressure of biotic stress. 相似文献
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A large‐scale survey of Citrus tristeza virus (CTV) was carried out from 2016 to 2018 in the Chlef Valley, one of the main citrus growing areas in Algeria. In this study a total of 1680 citrus trees from 93 commercial orchards were sampled. The collected samples were tested by direct tissue blot immunoassay analysis and by the double antibody sandwich enzyme‐linked immunosorbent assay technique, and 54 trees were identified as being infected with CTV. This result confirmed that 54 trees were infected by the virus, corresponding to an infection rate of 3.21% throughout the studied area. Five of these local CTV sources were chosen for further molecular investigations to determine the genotype associated with the CTV isolates now spreading in the Chlef area. Characterization with multiple molecular markers showed the presence of the T30 and VT genotypes. This result allowed confirmation of the presence of a virulent strain belonging to the VT genotype. The other CTV isolates were similar to those from the Mitidja region, which showed 99% nucleotide identity with the Spanish mild CTV isolate. This early finding of a strain belonging to the VT genotype is an issue for Algerian citrus producers and needs rapid actions to be taken by the National phytosanitary services, extending the surveillance to other citrus production regions and uprooting the infected trees. 相似文献
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D. A. Read M. F. Palacios J. Kleynhans J. Figueroa L. Foguet B. Stein G. Pietersen 《European journal of plant pathology / European Foundation for Plant Pathology》2018,151(2):329-340
Citrus tristeza virus (CTV) is the most severe viral pathogen of citrus and elicits a wide range of devastating disease symptoms. Grapefruit cultivars (Citrus x paradisi) are the most sensitive among citrus to the effects of CTV infections. Grapefruit is an important crop within the north-western Argentine citrus industry; however, production has been affected by CTV stem-pitting. In general, CTV diversity within South America is poorly studied, with data on grapefruit CTV populations being particularly limited. In this study, 50 samples were collected from Star Ruby, Henninger’s Ruby and Ruben Pink cultivars, within the provinces of Tucumán, Salta and Jujuy in north-western Argentina. The CTV p33 gene was PCR amplified and the resulting amplicons sequenced with Sanger sequencing. A subset of these amplicons was sequenced with Illumina MiSeq sequencing. AT-1-like sequences were dominant within the majority of populations, as determined by Sanger sequencing, followed by sequences clustering within the unresolved Kpg3/SP/T3 and RB clades. Sequencing by Illumina MiSeq confirmed this, as well as detecting minor sequence types within the HA 16–5, VT, B165 and A18 clades. 相似文献
9.
Adkar-Purushothama Charith R. Quaglino Fabio Casati Paola Bianco Piero A. 《植物病害和植物保护杂志》2010,117(6):241-243
Journal of Plant Diseases and Protection - Tristeza and Huanglongbing are the most important diseases of citrus caused by Citrus tristeza virus (CTV) and ‘Candidatus Liberibacter’... 相似文献
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Darjeeling and Sikkim hills of India are well known for production of mandarin orange (Citrus reticulata). The recent spread of Citrus tristeza virus (CTV) has threatened the citrus cultivation in this region. During a survey in Darjeeling and Sikkim hills, pomelo trees were recorded as CTV free. Since pomelo trees did not show any disease appearance, a study was undertaken to ascertain whether they are resistant to CTV infection or resistant to aphid feeding or both. Toxoptera citricida, the most efficient aphid vector and which is abundantly present in this region, did not feed on pomelo when other Citrus species such as mandarin, kagzi lime and rough lemon were available. Additionally, CTV isolates of Darjeeling and Sikkim hills were not transmissible to pomelo either by T. citricida or grafting. We report for the first time that pomelo is resistant to isolates of CTV present in this region. 相似文献
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Citrus tristeza virus (CTV) is the causal agent of the most important virus disease of citrus. Numerous CTV isolates differing in biological and molecular characteristics have been reported worldwide. Recently, CTV was detected in Italy in several citrus crops from three separate areas: (1) Cassibile, province of Syracuse; (2) Massafra, province of Taranto; and (3) Belpasso, province of Catania. CTV isolates from Massafra and Cassibile were mild, whereas isolates from Belpasso induced severe symptoms. To study the genetic variation of CTV populations of these areas, 150 samples per area were examined by single strand conformation polymorphism (SSCP) and nucleotide sequence analysis of CTV gene p20. All isolates from the same area showed the same SSCP pattern whereas for each area a different SSCP pattern was obtained. The Massafra and the Cassibile isolates had a nucleotide identity higher than 99% with a mild isolate from Spain and about 92% with the Belpasso isolates, which were similar (identity higher than 99%) to severe isolates from California and Japan. These results suggest at least two independent introductions of CTV in Italy, probably by import of CTV-infected budwoods. Within each area, the virus population was homogeneous suggesting diffusion of CTV by aphid transmission.
The GenBank accession numbers of the sequences reported in this paper are: AY262000, AY263360 and AY263361 corresponding to gene p20 of CTV isolates from Massafra, Cassibile and Belpasso (Italy), respectively. 相似文献
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Latanya C. Fisher Paula F. Tennant Wayne A. McLaughlin 《European journal of plant pathology / European Foundation for Plant Pathology》2010,127(1):1-6
An island wide survey for Citrus tristeza virus (CTV) in citrus orchards across Jamaica (13 regions) was conducted over 2 years. Trees (1, 885) showing virus-like symptoms
as well as asymptomatic trees were randomly sampled for testing by ELISA and 55 samples from the 6 major citrus growing regions
were graft inoculated on indicator plants. Most samples (74%) reacted to polyclonal antibodies against CTV in ELISA, while
20% were positive in tests using monoclonal antibodies specific to severe CTV strains. Samples collected from the 6 major
citrus growing regions produced vein clearing and stem pitting symptoms on Mexican lime indicator plants (87%). In addition,
stem pitting symptoms were induced on Duncan grapefruit, sweet orange, sour orange or sweet orange grafted on sour orange.
Nucleotide sequencing of the coat protein gene sequences isolated from these samples indicated high identities (88 to 95.5%)
among the Jamaican isolates and previously reported stem pitting strains from Central and North America and Eurasia (88 to
100%). The results suggest a shared ancestry with isolates from other geographical locations, rather than geographical speciation,
and presumably separate CTV introductions into Jamaica. 相似文献
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Stem segments from Mexican lime, sweet orange, grapefruit, Citrus excelsa and alemow, infected with five citrus tristeza virus (CTV) isolates, were cultured in vitro . Regeneration of roots and shoots were modified as a result of infection. The effect of CTV on the morphogenesis of stem segments cultured in vitro depended on the CTV isolate and the plant host, and showed a correlation with the in vivo effects observed in biological indexing. Evaluation of the morphogenic response of stem segments of Mexican lime and grapefruit can be used as an additional tool for the biological characterization of CTV isolates. The symptoms on sweet orange plants obtained from regenerated shoots indicated that CTV is unevenly distributed in the host plant cells and that the regeneration process may be utilized as a tool to separate strains from complex field isolates. 相似文献
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ABSTRACT Aphid vector species population composition is known to affect the spatial patterns of citrus tristeza virus (CTV) and the changes in these patterns over time. However, the biological processes that are associated with virus spread have not been well defined. The spatiotemporal dynamics of CTV were examined using data collected from research plots in the Dominican Republic and Costa Rica, where the brown citrus aphid (BCA), Toxoptera citricida, was the predominant species, and in Florida, where the BCA was absent and the melon aphid, Aphis gossypii, was the predominant vector. Data were analyzed using a spatiotemporal stochastic model for disease spread, and parameter values were evaluated using Markov chain Monte Carlo stochastic integration methods. Where the melon aphid was the dominant species, the model parameter likelihood values supported the hypothesis that the disease was spread through a combination of random background transmission (transmission originating from inoculum sources outside the plot) and a local interaction (transmission from inoculum sources within the plot) operating over short distances. Conversely, when BCA was present, results often suggested a local short-range transmission interaction that was not restricted to nearest-neighbor interactions and that the presence of background infection was not necessary to explain the observations. 相似文献
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Narayan Rishi 《Journal of General Plant Pathology》2009,75(1):1-18
India has a diverse agroclimate representing tropical, subtropical and temperate climates with zones ranging from average
to high in temperature, humidity and rainfall; from low to scarce rainfall in deserts to cold to very cold plains and upland
areas. Thus it is the home of one of the richest flora and fauna in the world. For pests and pathogens, too, tropical and
subtropical climates are ideal for growth and development. A majority of the world’s fruits, vegetables, cereals, pulses,
oil seed crops, fiber crops, sugarcane, spices, and ornamentals are cultivated in India. Virus diseases and their vectors
are also in abundance. Since ancient times, virus-like diseases and management practices have been known in India. This knowledge
has now been revived and adopted in organic farming, especially for medicinal and aromatic plants. Current trends for extensive
and intensive agriculture, open international agricultural trade, and thus food security and sustained economy have brought
new challenges in the fight against virus diseases. In this changing scenario, current diseases of significance are caused
by begomoviruses, badnaviruses, cucomoviruses, potyviruses, ilarviruses in crops such as vegetables, fruits, ornamentals,
fiber crops, and sugarcane. Variability in the viruses is also common. Briefly reviewed here is the positive effect of an
isolate of Rice necrosis mosaic virus; when artificially inoculated on jute and mesta fiber crops enhanced their fiber contents. Diseases of significance, e.g.,
leaf fleck disease of sugarcane, citrus yellow mosaic disease, banana bunchy top, banana bract mosaic, mungbean yellow mosaic,
mosaic in chrysanthemum, gladiolus and orchids are also discussed. Efficient, reliable diagnostic tools have been developed
and used extensively. Some of the advanced laboratories have been accredited for virus indexing under the National Certification
System for tissue-cultured plants. International standards for phytosanitary measures have been promulgated, and a mandatory
nodal agency is in place for the conservation and exchange of germplasm; a Containment Level-4 facility to examine incoming
transgenics and a fully equipped laboratory to intercept virus-infected plant material are functional. A National Agricultural
Biosecurity System will soon be in place. All these measures are essential to protect agricultural systems and to compete
in the international agriculture market. Continued vigilance, disease mapping and adopting the latest technology are required
to practice sustainable agriculture. 相似文献
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柑橘衰退病毒(Citrus tristeza virus,CTV),柑橘碎叶病毒(Citrus tatter\|leaf virus,CTLV),柑橘裂皮病类病毒(Citrus exocortis viroid,CEVd)和柑橘黄龙病(Huanglongbing, HLB)亚洲种病原(Candidatus liberobacter asiaticus)是重要的柑橘嫁接传播病原。本文建立了同时检测HLB病菌、CTV、CEVd 和CTLV 4种柑橘嫁接病原的一步法、双温多重PCR检测技术体系,同时在体系中设置内参基因。应用该体系快速评价了4种嫁接传播病原在田间侵染情况,结果表明28个田间样品CTV、CEVd、CTLV和HLB感染率分别为89.3 %、17.9 %、10.7 %和28.6 %,接近半数样品为混合感染。并且将该方法应用于快速评价茎尖嫁接苗病毒的脱除情况。 相似文献