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1.
Hammond J 《Phytopathology》1998,88(9):965-971
ABSTRACT Antisera to the cytoplasmic inclusion proteins (CIPs) of bean yellow mosaic (BYMV), clover yellow vein (ClYVV), turnip mosaic (TuMV), sweet potato feathery mottle (SPFMV), and maize dwarf mosaic (MDMV) potyviruses were used to examine the relationships between the CIPs of 18 potyviruses. The antisera to CIPs of BYMV, ClYVV, TuMV, and SPFMV cross-reacted to most or all of the purified CIPs tested in western blot assays. The MDMV CIP antiserum reacted significantly only to the MDMV and sorghum mosaic virus CIPs. Reactivity of antisera to CIPs of dicot-infecting viruses was generally higher with CIPs of other dicot-infecting than with monocot-infecting potyvirus CIPs. Analysis of amino acid sequences of the CI genes of 11 well-characterized potyviruses suggested that epitopes specific for individual potyviruses are primarily in the C-terminal domains of the CIP, whereas epitopes shared among different viruses are clustered in the N-terminal domains. The most highly conserved predicted epitope overlaps the nucleotide binding motif of the N-terminal helicase domain of the CIP. Antibodies to this domain will probably be present in antisera to any potyvirus CIP and contribute to the cross-reactivity observed. Differences in the C-terminal domains may correlate with interactions between the CIP and coat protein necessary for replication and movement.  相似文献   

2.
Black locust (Robinia pseudoacacia L.) is an ornamental legume tree susceptible to several viruses. Virus diseases of black locust often go unrecognized making infected trees a prime inoculum source, not only for legumes, but also other plant species. In this communication we report, for the first time, two viruses, Papaya ringspot virus and Watermelon mosaic virus, associated with disease in black locust. Isolates of both viruses were partially characterized and seed transmission was examined. The high percentage of seed transmission suggests that this may be an important avenue for virus dissemination.  相似文献   

3.
ABSTRACT When two unrelated plant viruses infect a plant simultaneously, synergistic viral interactions often occur resulting in devastating diseases. This study was initiated to examine ultrastructural virus-virus interactions of mixed viral infections. Mixed infections were induced using potyviruses and viruses from other plant virus families. Novel ultrastructural paracrystalline arrays composed of co-infecting viruses, referred to as mixed virus particle aggregates (MVPAs), were noted in the majority of the mixed infections studied. When the flexuous rod-shaped potyvirus particles involved in MVPAs were sectioned transversely, specific geometrical patterns were noted within some doubly infected cells. Although similar geometrical patterns were associated with MVPAs of various virus combinations, unique characteristics within patterns were consistent in each mixed infection virus pair. Centrally located virus particles within some MVPAs appeared swollen (Southern bean mosaic virus mixed with Blackeye cowpea mosaic virus, Cucumber mosaic virus mixed with Blackeye cowpea mosaic virus, and Sunn hemp mosaic virus mixed with Soybean mosaic virus). This ultrastructural study complements molecular studies of mixed infections of plant viruses by adding the additional dimension of visualizing the interactions between the coinfecting viruses.  相似文献   

4.
玉米致死性坏死病是由玉米褪绿斑驳病毒(Maize chlorotic mottle virus,MCMV)和一种或多种马铃薯Y病毒科病毒复合侵染引起的。2014年1月在对云南省玉溪市玉米病毒病害的调查中发现了一些表现严重花叶、矮化叶片甚至整个植株坏死症状的玉米。对采集样品进行RT-PCR检测,所有样品中都同时检测到了MCMV和甘蔗花叶病毒(Sugarcane mosaic virus,SCMV),在一个样品中同时检测到了MCMV、SCMV和南方水稻黑条矮缩病毒(Southern rice black-streaked dwarf virus)。  相似文献   

5.
永安地区发病辣椒植株表现小叶、黄化、丛枝、簇芽等症状。利用植原体16SrDNA基因的通用引物R16mF2/R16mR2和R16F2n/R16R2,对发病辣椒植株总DNA进行巢式PCR检测,获得约1.2kb的特异性DNA片段。经测序并在GenBank数据库进行比对分析,共获得4条植原体特定的16SrDNA基因序列(CHY-C4-1、CHYY1-1、CHY-Y7-1、CHY-G1-1)。将测得的4条序列与已报道的植原体序列进行同源性比对,并构建系统进化树,结果显示获得的4条植原体序列均聚类到16SrI组,其中CHY-Y1-1、CHY-Y7-1、CHY-G1-1与16SrI-B亚组植原体聚类到同一支,而CHY-C4-1与已报道的16SrI组内的6个亚组均未聚类到一支,因此建议将CHY-C4-1命名为新的亚组。利用iPhyClassifier在线分析软件对获得的4条植原体序列进行虚拟RFLP分析,结果与进化树获得的结果一致。  相似文献   

6.
The diversity of whitefly‐transmitted begomoviruses in Europe is low, most being exotic, introduced species. The only agriculturally important viruses are two species causing tomato yellow leaf curl. These viruses are believed to have originated in the Middle East but have since spread right across the Mediterranean region. Two ornamentals (Abutilon and Lonicera japonica) were introduced into Europe from the New World and the Far East, respectively, for the striking symptoms induced by the viruses which infect them. The virus infecting honeysuckle (Honeysuckle yellow vein mosaic virus) has been shown to be part of newly identified cluster of begomoviruses which require an additional component, a satellite molecule termed DNA β, to induce symptoms in their host plants. A further begomovirus, Ipomoea yellow vein virus, which infects the weed Ipomoea indica, is present in the Mediterranean region. The precise origin and relationship of this virus to other begomoviruses is unclear.  相似文献   

7.
<正>0 Introduction The family Potyviridae accounts for approximately 30%of know n plant viruses, infecting an extensive range of dicots and monocots and causing enormous damage in agriculture[1]. The genus Potyvirus is the largest genus in this family and all members of the Potyvirus share similar common characteristics and a same genome organization. Virions of potyviruses are non-enveloped,flexuous,  相似文献   

8.
Agglutination of Staphylococcus aureus bacteria particles, conjugated with specific virus antibodies, has been used to identify a wide range of plant viruses in crude sap extracts. The test distinguishes between seven different potyviruses in homologous and heterologous reactions, but does not distinguish different strains of bean yellow mosaic virus. The sensitivity of the virobacterial agglutination (VBA) test compares favourably with virus detection in ISEM particle trapping and local lesion assay and is only slightly less sensitive than direct ELISA tests. The test is more sensitive and simpler to user than latex particle agglutination tests.  相似文献   

9.
A simple one-tube one-step RT-PCR assay with degenerate primers followed by direct sequencing of a 327 bp coat protein gene fragment was used to identify the potyviruses infecting vanilla. With this technique, unambiguous species allocation was achieved for 34 potyvirus-infected vanilla samples collected in the Indian Ocean and the Pacific areas between 1997 and 2005. Virus identification relied on blast homology and nucleotide identities of 162 to 327 nt fragments with known potyvirus sequences. Species allocation was confirmed by neighbour-joining of the 149 nt common to 32 vanilla sequences and 51 known potyviruses. Subject to further identification, these data revealed four additional Potyvirus species that may infect vanilla: Bean yellow mosaic virus , Cowpea aphid-borne mosaic virus , Ornithogalum mosaic virus and Wisteria vein mosaic virus . The procedure was rapid, cost-effective, easy to use and showed a good taxonomic discriminating value. It also enabled the identification of potyviruses in adjacent weeds and should thus aid the understanding of outbreaks of potyviruses occurring in varied epidemiological circumstances.  相似文献   

10.
11.
A potyvirus causing severe mosaic symptoms was isolated from Senna occidentalis (syn. Cassia occidentalis ) in the Yemen Republic and Ethiopia. It was transmitted mechanically and by Myzus persicae in a non-persistent manner. The flexuous, rod-shaped particles had a mean length of 830 nm, and pinwheels and scrolls were observed by electron microscopy of thin sections of infected Nicotiana clevelandii leaves. Its host range was narrow with only a few legume species, Nicotiana clevelandii and N. benthamiana susceptible to experimental infection. This virus was purified from N. clevelandii and the coat protein had a molecular mass of 34-5 kDa. It reacted positively in ELISA with monoclonal antibody 197 that is specific for potyviruses, but was not decorated by antibodies to any other potyvirus tested when examined by electron microscopy. The virus has been tentatively named cassia severe mosaic potyvirus.  相似文献   

12.
Vanilla viruses in the South Pacific   总被引:1,自引:0,他引:1  
Surveys for viruses affecting Vanilla fragrans and V. tahitensis carried out in Cook Islands, Fiji, Niue, Tonga and Vanuatu detected cymbidium mosaic potexvirus and odontoglossum ringspot tobamovirus in all countries; vanilla necrosis potyvirus in Fiji, Tonga and Vanuatu; and vanilla mosaic potyvirus in Cook Islands, Fiji and Vanuatu. For all these viruses the surveys extended the previously known distribution in the South Pacific. Other, unreported potyviruses and rhabdovirus-like particles were detected from Fiji and Vanuatu. Symptoms associated with potyvirus infection (leaf distortion, sunken chlorotic patches, stem necrosis and vine die-back) were found in a majority of plantings in Fiji, Tonga and Vanuatu; in Fiji and Tonga there were instances where up to 50% of the plants in farmers' plots were affected.  相似文献   

13.
Characterization of a new potyvirus isolated from peanut (Arachis hypogaea)   总被引:1,自引:0,他引:1  
During a survey of viruses of peanuts in South Africa a mechanically transmissible virus was isolated from a plant exhibiting chlorotic ringspots and blotches on the leaves. Typical potyvirus-like flexuous particles were detected by electron microscope examination. Pinwheel-shaped and laminated inclusions in ultrathin sections, reaction with a monoclonal antibody directed to a potyvirus common epitope, a single 33 kDa coat protein and aphid transmission using Myzus persicae all confirmed that the virus was a subdivision II member of the Potyviridae. Host range studies suggested that the virus was none of the previously reported potyviruses of peanuts or of subdivision II potyviruses. The serological relationships of the virus were studied using a range of 17 antisera to potyviruses in ELISA and immunosorbent electron microscopy (ISEM). The isolate reacted weakly with antisera to plum pox virus and bean yellow mosaic virus in ISEM only. Nucleotide sequence of a 624 bp DNA product was obtained following immuno-capture with a potyvirus common epitope antiserum, cDNA synthesis and PCR amplification with potyvirus specific primers which amplify the 3' untranslated region and a part of the coat protein gene. The sequence was only distantly related to a number of potyviruses, whether amino acid or nucleotide sequences were used for comparisons. It is proposed that the virus be named peanut chlorotic blotch virus and be accepted as a new member of the genus Potyvirus in the family Potyviridae.  相似文献   

14.
ABSTRACT Using molecular markers, this work compares the genetic diversity in Colletotrichum gloeosporioides infecting species of the tropical forage legume Stylosanthes at the center of origin in Brazil and Colombia with that of Australia, China, and India, where Stylosanthes spp. have been introduced for commercial use. There was extensive diversity in the pathogen population from Brazil, Colombia, China, and India. The Australian pathogen population was least diverse probably due to its geographical isolation and effective quarantine. The extensive diversity in China and India means that threats from exotic pathogen races to Stylosanthes pastures can potentially come from countries outside the South American center of origin. In Brazil and India, both with native Stylosanthes populations, a high level of genetic differentiation in the pathogen population was associated with sites where native or naturalized host population was widely distributed. There was limited genetic diversity at germplasm evaluation sites, with a large proportion of isolates having identical haplotypes. This contrasts recent pathogenicity results for 78 of the Brazilian isolates that show hot spots of complex races are more common around research stations where host germplasm are tested, but few are found at sites containing wild host populations. For a pathogen in which the same races arise convergently from different genetic backgrounds, this study highlights the importance of using both virulence and selectively neutral markers to understand pathogen population structure.  相似文献   

15.
Chickpea was surveyed for viruses in the main growing areas of the crop in Morocco. A total of 36 fields was examined and 167 samples with symptoms suggestive of virus infection were collected. Serological testing using polyclonal antisera and monoclonal antibodies revealed the presence of the following viruses: alfalfa mosaic alfamovirus (AMV), broad bean mottle bromovirus (BBMV), broad bean stain comovirus (BBSV), bean yellow mosaic potyvirus, cucumber mosaic cucumovirus (CMV), faba bean necrotic yellows nanavirus (FBNYV), lettuce mosaic potyvirus, pea seed-borne mosaic potyvirus (PSbMV), and luteoviruses. Field symptoms of these viruses in chickpea comprised mosaics, yellowing, stunting, narrowing of leaflets and bushy growth. AMV, luteoviruses and potyviruses were found spread over the chickpea-growing regions, while BBSV, BBMV, and FBNYV were confined to some areas. Virus incidence per field varied from 1 to 40% for luteoviruses and from 1 to 20% for mosaic-inducing viruses. AMV, luteoviruses, potyviruses and CMV were detected in 89, 83, 75 and 42%, respectively, of the surveyed fields. BBMV, BBSV and FBNYV were less widespread at the national level. This is the first report of the occurrence of viruses other than CMV and BBMV in chickpea in Morocco, and the first record of the natural occurrence of BBSV and PSbMV in chickpea.  相似文献   

16.
Dasheen mosaic virus (DsMV), Turnip mosaic virus (TuMV), Konjac mosaic virus (KoMV) and Zantedeschia mild mosaic virus (ZaMMV) are important potyviruses previously identified in calla lily plants in Taiwan. In order to save time and cost of virus detection, a multiplex RT-PCR assay was developed for these calla potyviruses. Specific primers for each virus were designed based on the sequences of 3′ terminal region of respective viruses. To prevent false negative results, a primer pair specific to plant mitochondrial nad5 mRNA was used to produce a 185-bp fragment as an internal control of RT-PCR. The specificities of primers were confirmed by means of simplex and multiplex PCR assays. Optimal primer concentration ratio was identified by multiplex PCR assay. Total RNAs purified from virus-infected plants were used directly or mixed in different combinations, and then tested by multiplex RT-PCR. The result indicated that the expected RT-PCR products could be specifically amplified and identified on the basis of their molecular sizes. The detection sensitivity of multiplex RT-PCR was 25–625 times higher than that of indirect-ELISA (I-ELISA) depending on the virus. When applied to field surveys, multiplex RT-PCR could detect more single as well as mixed infection samples than I-ELISA. Accordingly, our multiplex RT-PCR assay provides a simple, rapid and reliable method for multiple potyvirus detection in calla lily.  相似文献   

17.
Aphanomyces euteiches (races 1 and 2) causes root rot of alfalfa; however, its population biology and distribution are poorly understood where alfalfa is a major crop. The objectives of this study were to (1) characterise the distribution and frequency of races of A. euteiches in Illinois alfalfa fields, (2) determine host range of A. euteiches on cultivated and native legumes, and (iii) to describe genetic diversity and population genetic structure of A. euteiches in alfalfa fields. To accomplish this, soil samples (n = 103) were collected from 30 alfalfa fields in 18 Illinois counties. Using the susceptible cv. ‘Saranac’, 148 isolates of A. euteiches were baited from the soil. The virulence phenotype of isolates representing all 18 counties was tested, and 54% were R1 and 46% were R2. Both races were detected in 61% of the counties, whereas only R1 was detected in 22% and R2 in 17%. Thirteen legume hosts for isolates from alfalfa fields were identified based on symptoms and/or production of oospores in roots. In addition to six previously known hosts, seven species were susceptible to infection: kura clover, purple prairie clover, white prairie clover, ladino clover, hairy vetch, Canadian milk vetch, and Illinois tick trefoil. AFLP analysis revealed high levels of genetic diversity among the isolates from different fields and counties and a lack of genetic structuring of populations based on race or geographical origin. The results suggest that populations of A. euteiches in alfalfa fields are diverse, often composed of races 1 and 2, and create risk for alfalfa and to multiple cultivated and native legume species.  相似文献   

18.
19.
Serotypic variation in turnip mosaic virus   总被引:7,自引:0,他引:7  
Jenner  Keane  Jones  & Walsh 《Plant pathology》1999,48(1):101-108
A panel of 30 monoclonal antibodies (MAbs) was produced against four isolates of turnip mosaic virus (TuMV). The panel was tested in plate-trapped antigen ELISA tests against 41 TuMV isolates (with different host and geographical origins and of differing pathotypes). The antibodies were also tested against four other potyviruses (bean common mosaic virus, bean common mosaic necrosis virus, lettuce mosaic virus and zucchini yellow mosaic virus). The reactions were assessed quantitatively (using multivariate analysis) and qualitatively (using the standard deviation obtained against healthy leaf material). The MAbs recognized 16–17 TuMV epitopes that were not present in the other potyviruses and a further two potyvirus epitopes. The isolates were grouped into three serotypes. Only one isolate did not fit this grouping. The classification of seven isolates in coat protein amino acid sequence homology groups correlated with serotypes. There was no correlation between serotype and pathotype, or between reactions to individual MAbs and single lines. There was therefore no evidence that the epitopes recognized by the MAbs are elicitors for the resistance genes present in the Brassica napus lines. However, the sensitivity and specificity of the MAbs will be useful for both routine detection of TuMV and fundamental studies on plant–virus interactions.  相似文献   

20.
近年来宏基因组学研究的普及大大丰富了人们对RNA病毒多样性的认识,但对这些新发现病毒的生物学特性却所知甚少。本文围绕RNA病毒中一类重要的负单链RNA病毒--弹状病毒与其昆虫寄主互作的研究进行综述,总结已发现的弹状病毒及其昆虫寄主类型,共有20个属144种弹状病毒可以感染14个属的昆虫;根据已有的系统进化研究对弹状病毒的寄主起源进行推测;并以感染黑腹果蝇Drosophila melanogaster的sigma病毒(Drosophila melanogaster sigma virus,DMelSV)为主要对象,就弹状病毒引起的CO2麻痹致死症状以及昆虫寄主对其的免疫反应研究进行总结,而在对黑腹果蝇的研究中发现很多非经典免疫通路中的新抗病毒基因,暗示存在新的抗病毒免疫通路;通过飞虱、叶蝉与其传播的植物弹状病毒以及长须罗蛉Lutzomyia longipalpis与其传播的脊椎动物病毒的互作研究,发现Toll、IMD信号通路、细胞自噬及小RNA干扰(small interfering RNA,siRNA)通路等可能与昆虫对弹状病毒的免疫反应相关。昆虫是弹状病毒主要的寄主和媒介,也是病毒遗传多样性的储主,因此更好地研究和了解昆虫寄主与弹状病毒的相互关系,有助于病毒致病和传播机制以及昆虫抗病毒免疫机理的深入研究。  相似文献   

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