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1.
An association of a begomovirus with leaf curl symptoms on Cleome gynandra was detected using a polymerase chain reaction (PCR) with begomovirus-specific primers. Further, the complete DNA-A of the begomovirus was cloned and sequenced. BLAST analysis of the sequence data revealed 92–99% identities and close relationships with several isolates of Ageratum enation virus (AgEV); therefore, we identified the virus associated with leaf curl symptoms of C. gynandra as an isolate of AgEV. This report is the first on the detection of AgEV in plants of C. gynandra with leaf curl in India.  相似文献   

2.
A whitefly transmitted begomovirus was detected by PCR using begomovirus-specific primers from naturally infected Calendula officinalis plants showing yellow vein disease symptoms. An approximately 800 bp PCR amplicon was cloned and sequenced to identify the species of the virus isolate. Analysis of nucleotide sequence data resulted in its identification as the complete coat protein gene open reading frame (CP ORF) of 771 bp, which encoded 256 amino acid residues. The coat protein of the virus isolate shared maximum identities of 96–97% with four strains of Tobacco curly shoot virus (ToCSV) and an Ageratum enation virus (AgEV) during BLAST analysis of sequence data. Nucleotide- and amino acid-based phylogenetic analysis revealed the close relationship of the isolate with ToCSV strains, therefore it has been identified as an isolate of ToCSV and C. officinalis is considered to be a new host of ToCSV begomovirus. Association of a DNA-β molecule with the virus isolate was also detected by PCR and Southern hybridization tests using DNA-β specific primers and probe.  相似文献   

3.
A viral isolate from Egypt associated with symptoms of enations and leaf curling on hollyhock (Althea rosea) was characterized at the cytopathological and molecular levels. Microscopic observations showed that enations resulted from a reorganization of the vascular tissues, including activation of a cambial activity in the phloem, the development of a palisade parenchyma in place of a spongy one and the differentiation of minor vascular tissues. From this isolate, the full-length DNA-A of a begomovirus (family Geminiviridae) was cloned and sequenced. This genome exhibited a genetic organization similar to that of other old-world begomoviruses like Tomato yellow leaf curl virus from Israel and Ageratum yellow vein virus from Singapore. However, its sequence was significantly distinct (similarity < 69%) from any other geminivirus. This begomovirus was thus considered as representative of a new viral species named Althea rosea enation virus (AREV). AREV was agroinfectious on Nicotiana benthamiana, on which it induced a severe leaf-curling and vein distortion, but could not re-establish infection on A. rosea. To determine if AREV was also associated with a similar disease affecting okra in Upper-Egypt, the partial sequence of the coat protein gene of an isolate was determined. It exhibited 90% nt identity with the hollyhock isolate (97% amino acid), suggesting a genetic heterogeneity in the begomovirus population associated with the enation diseases.  相似文献   

4.
In 2005, severe leaf curling and yellowing were observed on tomato plants on Ishigaki Island. Because the symptoms were consistent with infection by a begomovirus, we used a polymerase chain reaction (PCR) with specific primers for begomovirus DNA-A and DNA satellite component (DNA-β) and detected products of the expected sizes from symptomatic tomato plant samples. DNA sequence analyses of the PCR products revealed that the symptomatic tomato plants were associated with Ageratum yellow vein virus (AYVV) infection. We confirmed AYVV transmission from the naturally infected weed host, Ageratum conyzoides, to healthy tomato plants by the insect vector Bemisia tabaci B biotype. This report is the first of AYVV occurrence in Japan.  相似文献   

5.
The virus causing horsegram (Macrotyloma uniflorum) yellow mosaic disease has been shown to be a typical Old World bipartite begomovirus. The viral origin of the disease has been established through agroinoculation of horsegram using partial tandem repeat clones of both DNA-A and DNA-B. The DNA-A genome shows less than 89% identity with the corresponding sequences of all the begomoviruses in the databases earlier to this sequence submission (AJ627904). Therefore Horsegram yellow mosaic virus (HgYMV-[IN:Coi]) can be considered to be a new species of the genus Begomovirus (family Geminiviridae). Phylogenetic analysis shows that this virus is part of the cluster of mungbean yellow mosaic viruses of legumes from South and South East Asia.  相似文献   

6.
Leaf samples of Cucurbita pepo with yellow mosaic disease symptoms were collected in 2012. Rolling circle amplification and PCR amplification with begomovirus-specific primers confirmed the presence of an Old World bipartite begomovirus, an alphasatellite and a betasatellite. Molecular analysis of full-length sequences showed that Tomato leaf curl New Delhi virus (DNA-A) is associated with its cognate DNA-B, Papaya leaf curl betasatellite and a novel alphasatellite. To the best of our knowledge, this is the first report of an alphasatellite and a betasatellite associated with a bipartite begomovirus.  相似文献   

7.
Tomato leaf curl disease (ToLCD) affected 25% of the tomato crop in Chitrakoot, India and symptomatic leaves were collected for molecular assay. The complete sequences of bipartite begomovirus DNA-A and a betasatellite DNA were amplified. In a sequence analysis, begomovirus DNA-A and betasatellite shared highest sequence identity (91–99%) with Tomato leaf curl New Delhi virus (ToLCNDV) DNA-A and chili leaf curl betasatellite (ChLCB), respectively. The virus was transmitted by whitefly to tomato plants and caused ToLCD symptoms with 70% transmission rate. To our knowledge, this is the first report of the natural occurrence of ToLCNDV and ChLCB in India.  相似文献   

8.
Leaf curl in Zinnia elegans was observed in a subtemperate region in northern India, and the causal organism was identified as Ageratum enation virus (AEV). The virus appeared to be monopartite and associated with nanovirus-like satellite DNA1. The whole genome was amplified by rolling circle amplification, cloned, and sequenced using a primer walking strategy. The genome (FN543099) was composed of 2753 nucleotides (nt) and that of DNA1 (FN543100) of 1374 nt. DNA-β was not detected from any of the infected samples. The study presents the first report of a begomovirus from Zinnia spp. in India and the complete nucleotide sequence characterization of AEV associated with nanovirus-like satellite DNA1.  相似文献   

9.
Severe mosaic, yellowing and stunting symptoms were observed on petunia (Petunia hybrida L.) growing in pots at NBRI and in various gardens of Lucknow, India. The association of Cucumber mosaic virus (CMV) with the mosaic disease was detected based on positive bioassay on susceptible hosts, isometric cored virus particles of ~28?nm during electron microscopic observations in leaf dip preparations and positive amplification of expected size (~650?bp) during RT-PCR using coat protein gene specific primers. Further, the complete RNA 3 genomic fragment of virus isolate was amplified by RT-PCR using RNA 3 specific primers. The obtained amplicons of ~2.2 Kb were cloned and sequenced. The analysis of sequence data of RNA 3 revealed highest sequence identities (96%) with several CMV strains which belong to subgroup IB. The virus isolate also showed closest phylogenetic relationships with banana strain of CMV of subgroup IB (Acc. EF178298) reported from India. To the best of our knowledge, we report the first molecular characterization of CMV strain of subgroup IB causing severe mosaic disease on petunia in India.  相似文献   

10.
Leaf samples (five) from brinjal/eggplant fields showing upward leaf curling symptoms were collected from Varanasi, Uttar Pradesh state, India. The full length genome of begomovirus and associated betasatellite were amplified by PCR, cloned and sequenced. Sequences of homologous DNA-A and its betasatellite in all samples were the same. The samples failed to amplify DNA-B, suggesting that the begomovirus associated with leaf curl disease of eggplant was monopartite. The complete genome (homologous of DNA-A) consists of 2758 nts, whereas the betasatellite has 1352 nts and the genome organization is typical of Old World begomoviruses. The sequence analysis showed high levels of nucleotide sequence identity (79.8–91.7%) of virus with Tomato leaf curl Joydebpur virus (ToLCJoV) infecting chilli in India, suggesting it as a strain of ToLCJoV based on the current ICTV taxonomic criteria for begomovirus strain demarcation. However, the betasatellite associated was identified as a variant of Tomato leaf curl Bangladesh betasatellite (ToLCBDB), with which it shared highest sequence identity of 84.7–94.8%. Phylogenetic analyses of the genome further supported the above results. The recombination analyses of both genome and betasatellite showed that a major part of genome sequences are derived from begomoviruses (ToLCJoV, ChiLCuV, AEV) infecting chilli, tomato, ageratum and betasatellite from PaLCuB as the foremost parents in evolution, suggesting this as a new recombinant virus strain. This is the first report of a monopartite begomovirus and a betasatellite molecule associated with the leaf curl disease of eggplant.  相似文献   

11.
Two newly emerged begomoviruses were isolated from naturally infected tomato (Solanum lycopersicum) plants grown in greenhouses at Jeju Island and Dangjin in Korea and their genomes were characterized. These viruses-infected plants had very small leaves that curled upward, yellow margins and a leathery appearance, and a bushy and stunted appearance with short internodes. Nucleotide (nt) sequence analysis of their genomes showed that they have a DNA-A component of a monopartite begomovirus. Their genomes comprised 2763 and 2764 nucleotides with six open reading frames. The results of nt sequence similarity analysis of DNA-A genome between the two Korean isolates and isolates of Tobacco leaf curl Japan virus (TbLCJV), Honeysuckle yellow vein virus (HYVV), Honeysuckle yellow vein mosaic virus (HYVMV), and Eupatorium yellow vein virus in Japan (EpYVV) showed that they are likely similar to HYVV-[Masuda] (89.4–92.8% nt identity). Consequently, we tentatively propose the two isolates’ names as HYVV-Jeju and -DJ according to the ICTV geminivirus rules. Phylogenetic relationship analysis of 33 DNA-A genome sequences using PAUP* 4.0b10 and MrBayes revealed that HYVV-Jeju and -DJ belong to the Far East Asian begomovirus species complex. Within the Far East Asian begomovirus species complex, HYVV-Jeju and -DJ are distantly related to EpYVV, HYVMV, and TbLCJV groups. Based on the presence of a recombination fragment spanning the C3 ORF, a recombinant origin was suggested for both HYVV-Jeju and –DJ, with parents close to Japanese isolates HYVMV-[SP1:00] and Eupatorium yellow vein virus (EpYVV)-[Suya]. In addition, the presence of a further recombination fragment spanning the IR suggested the parents of HYVV-DJ were close to HYVV-Jeju and EpYVV-[Suya].  相似文献   

12.
During the spring of 2001, approximately 10 000 yellow passion flower plants, from two orchards in the county of Livramento de Nossa Senhora, Bahia State, Brazil, exhibited intense yellow mosaic symptoms and drastic reduction of the leaf lamina and plant development. A large population of whiteflies ( Bemisia tabaci ) was also found colonizing the plants. All field samples collected tested positive for Passion fruit woodiness virus in DAS-ELISA. Five out of 20 passion flower plants inoculated with adult whiteflies collected from diseased plants in the field developed symptoms 20–30 days after inoculation. Two of these plants gave a positive reaction in TAS-ELISA using antiserum against a begomovirus. Degenerated PCR primers amplified viral DNA fragments from the DNA-A and DNA-B components of a begomovirus infecting these plants. The fragment corresponding to the core region of the coat protein (DNA-A) was cloned and sequenced. A phylogenetic analysis placed this begomovirus isolated from passion flower in the same clade of the New World begomoviruses as several other species from Brazil. Based on the symptoms induced by this virus alone, the disease was tentatively named passion flower little leaf mosaic.  相似文献   

13.
Euphorbia mosaic virus (EuMV), a tentative species within the genus Begomovirus, was isolated from Euphorbia heterophylla plants growing in the Yucatan Peninsula, Mexico. The complete bipartite genome was cloned from total DNA extracts and the nucleotide (nt) sequence was determined. The DNA-A sequence of the EuMV-Yucatan Peninsula (EuMV-YP) isolate shared 95% nt identity with the partially characterized type EuMV isolate from Puerto Rico. The EuMV-YP genome organization was like that of other New World, bipartite begomoviruses. The DNA-A component was 2613 nt in size, while the DNA-B component was 2602 nt long. The 165-nt common region (CR) sequence for the DNA-A and DNA-B components shared a lower than expected nt identity of 86%. The organization and iterons of the putative AC1 binding site of EuMV-YP were similar to those of begomoviruses in the Squash leaf curl virus (SLCV) clade. Characteristic disease symptoms were reproduced in E. heterophylla plants inoculated at the seedling stage using the cloned viral DNA-A and DNA-B components, confirming disease aetiology. Results of an experimental host-range study for EuMV-YP indicated that it infected at least five species in three plant families, including the Euphorbiaceae ( E. heterophylla ), Solanaceae ( Datura stramonium , pepper, tomato) and Fabaceae (bean). Phylogenetic analysis of the DNA-A and DNA-B components indicated that EuMV-YP is a New World begomovirus and that it is a new member of the SLCV clade.  相似文献   

14.
In October 2009, vein yellowing disease was observed on the weeds Crassocephalum crepidioides and Ageratum conyzoides in a subtemperate region in northern India. Ageratum enation virus (AEV), along with a nanovirus like satellite DNA 1, was found to be associated with both weeds. The isolates had 99% identity with each other and with an isolate of AEV reported from Zinnia elegans from this region. To the best of our knowledge, this report is the first of any begomovirus infection in C. crepidioides in India and the first on AEV infecting C. crepidioides worldwide and A. conyzoides in India.  相似文献   

15.
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16.
The molecular and biological characterization of a begomovirus infecting the common weed Macroptilium lathyroides from Jamaica are reported. The virus showed 92% sequence identity to an isolate of Macroptilium yellow mosaic virus (MaYMV) from Cuba, but was distinct from the two other begomoviruses isolated from M. lathyroides , namely Macroptilium yellow mosaic Florida virus (80% identity) and Macroptilium mosaic Puerto Rico virus (68% identity). Hence, the Jamaican begomovirus was considered an isolate of MaYMV and called Macroptilium yellow mosaic virus -[Jamaica] (MaYMV-[JM]). In infectivity studies using cloned DNA-A and DNA-B genomic components, MaYMV-[JM] infected red kidney bean ( Phaseolus vulgaris ) and produced mild symptoms in Scotch Bonnet pepper ( Capsicum chinense ), but did not infect cabbage ( Brassica oleracea ). This information has implications for the development of strategies to control begomovirus diseases in Jamaica and elsewhere.  相似文献   

17.
Xiong Q  Fan S  Wu J  Zhou X 《Phytopathology》2007,97(4):405-411
ABSTRACT Ageratum conyzoides plants exhibiting yellow vein symptoms, collected near Haikou, Hainan Province, China, contained begomoviral DNA-A-like molecules. The complete sequences of the molecules from two samples, Hn2 and Hn2-19, were shown to consist of 2,768 and 2,748 nucelotides (nt), respectively. These sequences have more than 97% nucleotide sequence identity, but less than 86% identity with other reported begomovirus sequences. In line with the taxonomic convention for begomoviruses, Hn2 and Hn2-19 are therefore considered to represent isolates of a distinct begomovirus species, for which the name Ageratum yellow vein China virus (AYVCNV) is proposed. Sequence alignment shows AYVCNV has arisen by recombination among viruses related to Ageratum yellow vein virus, Papaya leaf curl China virus, and an unidentified begomovirus. Southern blot analyses revealed that all plants sampled contained molecules resembling DNAbeta. DNAbeta molecules from three samples were 1,323 or 1,324 nt long and had >98% sequence identity but <81% identity with previously reported DNAbeta sequences. Infectious clones of Hn2 and its associated DNAbeta were constructed and agroinoculated to plants. Hn2 alone caused sporadic asymptomatic systemic infection of Nicotiana benthamiana, N. glutinosa, Lycopersicon esculentum, Petunia hybrida, and A. conyzoides but its accumulation was much enhanced in plants co-inoculated with DNAbeta. The co-inoculated N. benthamiana, N. glutinosa, P. hybrida, and L. esculentum plants developed leaf curling or leaf crinkling symptom; those in A. conyzoides were typical of ageratum yellow vein disease. When the DNAbeta molecules associated with four other Chinese begomoviruses were coinoculated with Hn2 to N. benthamiana and N. glutinosa, the DNAbeta molecules were replicated, and the plants developed systemic symptoms of types that were specific for each DNAbeta. This illustrates that there is less specific interaction between monopartite begomovirus and DNAbeta than between the DNA-A and DNA-B of begomoviruses with bipartite genomes.  相似文献   

18.
A viral complex causing golden mosaic and leaf distortion (rugosity) in tomato plants was obtained from viruliferous whiteflies, and named TGV-Ub1. This complex was sap-transmitted from tomato to Nicotiana benthamiana . PCR amplification using universal begomovirus primers yielded two distinct fragments for DNA-A, suggesting that the TGV-Ub1 complex comprised at least two distinct viruses. Clones corresponding to full-length viral genomes were obtained from tomato plants infected with TGV-Ub1. Comparisons of the complete sequences of clones pUb1-49 (DNA-A), pUb1-62 and pUb1-81 (both DNA-B) indicated that they constitute novel western hemisphere begomoviruses. Clones pUb1-49 and pUB1-81 have identical common regions, thus representing the cognate DNA-A and -B of a novel begomovirus, named Tomato rugose mosaic virus (ToRMV). Clone pUb1-62 has a distinct common region from ToRMV and all other geminiviruses. A cognate DNA-A for pUb1-62 was not found. Clones containing 1·8 copies of the genomic components were constructed. Infectivity assays of these clones in tomato and N. benthamiana demonstrated that the clones corresponding to ToRMV systemically infected both hosts. Symptoms were analogous to those observed when using the pure isolates obtained in this study. The combination of pUb1-49 and -62 did not result in systemic infection, indicating that these components do not form a viable virus. ToRMV was sap-transmitted from N. benthamiana to N. benthamiana , and by grafting to Solanum tuberosum and Datura stramonium . ToRMV-A and ToRMV-B were detected in plants of Nicandra physaloides and Phaseolus vulgaris , respectively, growing in nearby tomato fields, in association with distinct DNA components.  相似文献   

19.
ABSTRACT Three isolates of the bipartite begomovirus Pepper golden mosaic virus (PepGMV) were characterized for genomic and biological properties. The complete nucleotide sequences of the DNA-A and DNA-B components were determined from infectious clones of PepGMV-Serrano (PepGMV-Ser), PepGMV-Mosaic (PepGMV-Mo), and PepGMV-Distortion (PepGMV-D). Nucleotide sequence identity among PepGMV components ranged from 91 to 96% for DNA-A and from 84 to 99% for DNA-B, with each PepGMV component most closely related to the corresponding component of Cabbage leaf curl virus (CaLCV). However, phylogenetic relationships among begomovirus components were incongruent because DNA-A of PepGMV and CaLCV share an inferred evolutionary history distinct from that of DNA-B. The cloned components of PepGMV-Ser, -Mo, and -D were infectious by biolistic inoculation to pepper but differed in symptom expression: PepGMV-Ser exhibited a bright golden mosaic, PepGMV-Mo produced a yellow-green mosaic, and PepGMV-D caused only a mild mosaic and foliar distortion followed by a "recovery" phenotype in which leaves developing after initial symptom expression appeared normal. Differences in symptoms also were observed on tomato, tobacco, and Datura stramonium. Progeny virus derived from clones of PepGMV-Ser and -Mo were transmitted from pepper to pepper by the B biotype of Bemisia tabaci; progeny virus derived from PepGMV-D clones was not transmissible by the B biotype. Reassortant genomes derived from heterologous DNA components of the three isolates were infectious in all possible pairwise combinations, with symptom phenotype in pepper determined by the DNA-B component. Collectively, these results indicate that the three virus isolates examined may be considered distinct strains of PepGMV that have the capacity to exchange genetic material.  相似文献   

20.
Begomovirus infection was suspected in tomato plants exhibiting symptoms of curling and deformation of leaves observed in a survey conducted in northern and central Peru. Rolling circle amplification and restriction fragment length polymorphism analyses suggested that a begomovirus was present in symptomatic plants. The full-length sequence of a begomovirus DNA component was determined, comprising 2591 nucleotides. Based on its genome organization, we suggest it corresponds to the DNA-A of a New World begomovirus. Less than 89% nucleotide sequence identity to known begomoviruses was found, indicating that it corresponds to an isolate of a distinct begomovirus species for which the name tomato leaf deformation virus (ToLDeV) is proposed. Different stretches of the genomic component have the highest sequence identity with different viruses compatible with a recombinant origin. Sequence segments shared common ancestors with isolates of either soybean blistering mosaic virus, tomato yellow spot virus, or tomato chino La Paz virus. Partial sequence analysis of begomovirus isolates present in symptomatic tomato samples collected in northern and central Peru suggested widespread occurrence of this new begomovirus. This is the first confirmation of a begomovirus infection in tomatoes in Peru.  相似文献   

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