First Report Of Cucumber Mosaic Virus Research Articles

The First Report of Cucumber Mosaic Virus Infecting Water Chestnut in China.

Water chestnut (Eleocharis dulcis), which is cultivated worldwide today, first originated in India and China. It is a popular seasonal aquatic vegetable valuable to people for its sweet crisp taste and rich nutrition. In October 2012, field-grown water chestnut seedlings (E. dulcis) showing mosaic, chlorotic, dwarfing, and malformed symptoms were observed in Fanggaoping Town, Tuanfeng County, Hubei Province, China. Sap from leaf-like stems of two symptomatic seedlings (BQ6 and BQ7) were mechanically inoculated onto Nicotiana glutinosa plants using 0.01 M phosphate buffer (pH 7.4) to investigate whether viral etiology was responsible for the disease. Typical symptoms of chlorosis and systemic mosaic similar to that inflicted by Cucumber mosaic virus (CMV) were observed on inoculated N. glutinosa leaves 13 days post inoculation, whereas mock inoculated seedlings remained symptomless. Three naturally field-grown symptomatic water chestnut and the inoculated N. glutinosa seedlings, together with a healthy water chestnut plant as negative control, were sampled. Double-antibody sandwich (DAS)-ELISA with antisera against CMV using commercial kits (Agdia, Elkhart, IN) was carried out to detect and confirm the presence of CMV. The symptomic water chestnut and inoculated N. glutinosa seedlings tested positive for CMV. Total RNAs were extracted using the SDS column isolation method from leaves of the inoculated N. glutinosa and stems of 13 field-grown symptomatic water chestnuts. The extracted RNAs were subjected to reverse transcription. The first-round PCR was carried out using the obtained cDNAs as template with the CMV specific primer set CMV-3F (5'-GCGATGYCGTGTTGAGAAG-3') and CMV-3R (5'-TTTAGCCGTAAGCTGGATGGA-3') targeting a 983-bp fragment covering 657 nt of the whole CP and partial flanking sequence within RNA3 referred as 'Fny' strain in GenBank (Accession No. D10538). The resulting amplicons were diluted 1:20 and further amplified with the nested-primer set CMV-P1 (5'-ATGGACAAATCTGAATCAACC-3') and CMV-P2 (5'-TAAGCTGGATGGACAACCCGT-3') targeting a fragment of 777 bp corresponding to the complete CP followed by part of 3'-UTRs of RNA3 (1). The amplicons of the expected size of ~777-bp were consistently amplified from 13 naturally infected water chestnuts and inoculated N. glutinosa. The PCR product derived from BQ6 isolate was cloned and three clones sequenced in both directions. The sequence (GenBank Accession No. KF268463) was analyzed by MEGA5 software (3). Sequence comparison of the complete CP gene of BQ6 isolate showed 98% nt and 99% amino acid (aa) identity with CMV isolate RP6 from South Korea (GenBank Accession No. KC527735) in subgroup I and had low similarities of 76% nt and 80% aa to that of CMV isolate infecting Trifolium from Hungary (GenBank Accession No. L15336) belonging to subgroup II of CMV. Phylogenetic analysis showed BQ6 isolate was more closely related to the isolates belonging to IB subgroup of CMV (GenBank Accession Nos. EF153739, DQ302715, and KC576805) (2). To our knowledge, this is the first report of CMV infecting water chestnut (E. dulcis) in China. CMV infection may pose a significant threat to water chestnut production. This result provide information to the producer that the CMV-free seedlings should be chosen for cultivation of water chestnut.

First Report of Cucumber mosaic virus on Melon in Bosnia and Herzegovina.

During July 2012, field-grown melon plants (Cucumis melo L.) with symptoms of mosaic, chlorotic mottling, and vein banding as well as blistering and leaf malformation were observed in one field in the locality of Kladari (municipality of Doboj, Bosnia and Herzegovina). Disease incidence was estimated at 60%. A total of 20 symptomatic plants were collected and tested with double-antibody sandwich (DAS)-ELISA using commercial polyclonal antisera (Bioreba AG, Reinach, Switzerland) against four the most commonly reported melon viruses: Cucumber mosaic virus (CMV), Watermelon mosaic virus (WMV), Zucchini yellow mosaic virus (ZYMV), and Papaya ringspot virus (PRSV) (1,3). Commercial positive and negative controls were included in each assay. Only CMV was detected serologically in all screened melon samples. Sap from an ELISA-positive sample (162-12) was mechanically inoculated to test plants using 0.01 M phosphate buffer (pH 7.0). The virus caused necrotic local lesions on Chenopodium amaranticolor 5 days after inoculation, while mild to severe mosaic was observed on Nicotiana rustica, N. glutinosa, N. tabacum 'Samsun,' Cucurbita pepo 'Ezra F1,' and Cucumis melo 'Ananas' 10 to 14 days post-inoculation. All five inoculated plants of each experimental host were DAS-ELISA positive for CMV. The presence of CMV in all naturally and mechanically infected plants was further verified by conventional reverse transcription (RT)-PCR. Total RNAs were extracted with the RNeasy Plant Mini Kit (Qiagen, Hilden, Germany) according to the manufacturer's instructions and used as template in RT-PCR. RT-PCR was carried out with the One-Step RT-PCR Kit (Qiagen) using primer pair CMVCPfwd and CMVCPrev (4), amplifying the entire coat protein (CP) gene and part of 3'- and 5'-UTRs of CMV RNA 3. Total RNAs obtained from the Serbian CMV isolate from Cucurbita pepo 'Olinka' (GenBank Accession No. HM065510) and healthy melon leaves were used as positive and negative controls, respectively. An amplicon of the correct predicted size (871 bp) was obtained from all naturally and mechanically infected plants as well as from positive control, but not from healthy tissues. The amplified product derived from isolate 162-12 was purified with QIAquick PCR Purification Kit (Qiagen) and sequenced directly using the same primer pair as in RT-PCR (KC559757). Multiple sequence alignment of the 162-12 isolate CP sequence with those available in GenBank, conducted with MEGA5 software, revealed that melon isolate from Bosnia and Herzegovina showed the highest nucleotide identity of 99.7% (100% amino acid identity) with eight CMV isolates originating from various hosts from Serbia (GQ340670), Spain (AJ829770 and 76, AM183119), the United States (U20668, D10538), Australia (U22821), and France (X16386). Despite the fact that CMV is well established in majority of Mediterranean countries and represents an important threat for many agriculture crops, including pepper in Bosnia and Herzegovina (2), to our knowledge, this is the first report of CMV infecting melon in Bosnia and Herzegovina. Melon popularity as well as production value has been rising rapidly and the presence of CMV may have a drastic economic impact on production of this crop in Bosnia and Herzegovina.

First Report of Cucumber mosaic virus Infecting Watermelon in Serbia.

In June 2012, field-grown watermelon plants (Citrullus lanatus L.) with virus-like symptoms were observed in Silbaš locality, South Backa District of Serbia. Plants infected early in the growing season showed severe symptoms including stunting, mosaic, mottling, blistering, and leaf curling with reduced leaf size, while those infected at later stages exhibited only a mild mosaic. Affected plants were spread across the field and disease incidence was estimated at 40%. Thirteen symptomatic watermelon plants were sampled and analyzed by double-antibody sandwich (DAS)-ELISA using a commercial diagnostic kit (Bioreba AG, Reinach, Switzerland) against the most important watermelon viruses: Cucumber mosaic virus (CMV), Watermelon mosaic virus (WMV), Zucchini yellow mosaic virus (ZYMV), Papaya ringspot virus (PRSV), and Squash mosaic virus (SqMV) (1). Commercial positive and negative controls and an extract from healthy watermelon tissue were included in each ELISA. Serological analyses showed that all plants were positive for CMV and negative for ZYMV, WMV, PRSV, and SqMV. The virus was mechanically transmitted from an ELISA-positive sample (449-12) to five plants of each Citrullus lanatus 'Creamson sweet' and Chenopodium amaranticolor using 0.01 M phosphate buffer (pH 7) with Serbian CMV isolate from Cucurbita pepo 'Olinka' (GenBank Accession No. HM065510) and healthy watermelon plants as positive and negative controls, respectively. Small necrotic lesions on C. amaranticolor and mild mosaic with dark green vein banding on watermelon leaves were observed on all inoculated plants 5 and 14 days post-inoculation, respectively. For further confirmation of CMV infection, reverse transcription (RT)-PCR was performed with the One-Step RT-PCR Kit (Qiagen, Hilden, Germany) using specific primers CMVCPfwd (5'-TGCTTCTCCRCGARWTTGCGT-3') and CMVCPrev (5'-CGTAGCTGGATGGACAACCCG-3'), designed to amplify an 871-bp fragment of the RNA3 including the whole CP gene. Total RNA from 12 naturally infected and five mechanically infected watermelon plants was extracted with the RNease Plant Mini Kit (Qiagen). Total RNA obtained from the Serbian CMV isolate (HM065510) and healthy watermelon plants were used as positive and negative controls, respectively. The expected size of RT-PCR products were amplified from all naturally and mechanically infected watermelon plants but not from healthy tissues. The PCR product derived from isolate 449-12 was purified and directly sequenced using the same primer pair as in RT-PCR (JX280942) and analyzed by MEGA5 software (3). Sequence comparison of the complete CP gene (657 nt) revealed that the Serbian isolate 449-12 shared the highest nucleotide identity of 98.9% (99.1% amino acid identity) with the Spanish melon isolate (AJ829777) and Syrian tomato isolate (AB448696). To our knowledge, this is the first report of CMV on watermelon in Serbia. CMV is widely distributed within the Mediterranean basin where it has a substantial impact on many agricultural crops (2) and is often found to be prevalent during pumpkin and squash surveys in Serbia (4). The presence of CMV on watermelon could therefore represent a serious threat to this valuable crop in Serbia.

Characterization of a Novel Cucumber mosaic virus Isolated from Petunia hybrida

Petunia hybrida is commonly used in landscapes and interiors for its attractive flower. Virus-like foliar symptoms, including a mosaic with dark green islands surrounding the veins and chlorosis on the leaf margins, were observed on a petunia plant from Icheon, Gyeonggido, Korea. Cucumber mosaic virus (CMV) was identified in the symptomatic petunia by serological testing for the presence of CMV coat protein (CP) with a direct antibody-sandwich-enzyme-linked immunosorbent assay. An agent was mechanically transmitted to indicator plant species including Chenopodium quinoa. Examination of the inoculated plant leaves by RT-PCR analysis and electron microscopy revealed the presence of specifically amplified CP products and spherical virions of approximately 28 nm in diameter, respectively, providing confirmation of a CMV infection. Analysis of CP sequences showed that CMV petunia isolate (CMVYJC) shared 82.5-100% amino acid sequence identity with CPs of representative CMV strains. Phylogenetic analysis of CPs supports that CMV-YJC is a member of CMV subgroup IA (CMV-IA) and has biological properties of CMV-IA on host species. To our knowledge, this is the first report of CMV from P. hybrida in Korea.

Natural occurrence of Cucumber mosaic virus infecting water mint (Mentha aquatica) in Antalya and Konya, Turkey

Natural occurrence ofCucumber mosaic virusinfecting water mint (Mentha aquatica) in Antalya and Konya, TurkeyAvirus causing a disease in mint (the aromatic and culinary plant) has recently become a problem in the Taurus Mountains, a mountain range in the Mediterranean region of Turkey. To detect the virus and investigate its distribution in the region, mint leaf samples were collected from the vicinity of spring areas in the plateaus of Antalya and Konya in 2009. It was found that Cucumber mosaic virus (CMV) was detected in 27.08% of symptomatic samples tested by DAS-ELISA. To the best of our knowledge, this is the first report of CMV on mint plants in this region of Turkey.

Identification of Three Distinct Classes of Satellite RNAs Associated With Two Cucumber mosaic virus Serotypes from the Ornamental Groundcover Vinca minor

Cucumber mosaic virus (CMV) is a cosmopolitan virus which may also have small satellite RNAs (satRNA) associated with it affecting symptom development. Vinca minor (periwinkle) plants exhibiting subtle mosaic symptoms tested positive for CMV by enzyme linked immunosorbent assay (ELISA). Double-stranded ribonucleic acid (dsRNA) analysis of CMV-Vinca field isolates in Nicotiana tabacum ‘Glurk’ suggested two sizes of putative satRNA associated with CMV. Immunocapture RT-PCR, cloning, and sequencing of the movement protein, coat protein, and satRNAs demonstrated serogroup 1A and serogroup 2 CMV helper strains and three distinct classes of satRNAs of four sizes. Further, two classes of satRNAs could be distinguished by their necrosis domains. Previously CMV was reported in V. minor in New Jersey. This is the first report of CMV in V. minor in Ohio and the first report of satRNA associated with CMV in V. minor in the United States. Accepted for publication 1 February 2012. Published 12 April 2012.

Identification of some viruses causing mosaic on lettuce and characterization of Lettuce mosaic virus from Tehran Province in Iran

Lettuce mosaic virus (LMV), Cucumber mosaic virus (CMV) and Tomato spotted wilt virus (TSWV) were identified in lettuce fields in Tehran province. In this study, 452 infected lettuce plants having viral infection symptoms including, mosaic, mottling, leaf distortion, stunting defective heading, were collected from the fields throughout Tehran province. Distribution of Lettuce mosaic virus (LMV), Cucumber mosaic virus(CMV), Tomato spotted wilt virus (TSWV) and Arabis mosaic virus (ArMV) were determined with DAS-ELISA. LMV, CMV and TSWV were found on lettuce in this region, but no infection by ArMV was found. Percentage of single infection by LMV, CMV or TSWV was 21, 16 and 10% respectively. Also, 16% of samples were co-infected with LMV+CMV, 8% with LMV+TSWV and 8% with CMV+TSWV. 5% of samples were infected to all of these viruses. LMV was found in 49%, CMV in 44% and TSWV in 31% of samples totally. Therefore, LMV is major agent of lettuce mosaic disease in Tehran province. This is the first report of occurrence of TSWV on lettuce in Iran and the first report of CMV and LMV in Tehran province. Three LMV infected samples were collected and their characteristics were determined. After mechanical inoculation, these isolates produced symptoms on Chenopodium quinoa, Chenopodium amaranticolor, Gomphrena globosa, Nicotiana benthamiana, Lactuca sativa cv. Mantilia and cv. Terocadero (which contains the mo11 resistance gene and susceptible respectively), but not cv. Salinas 88 (which contains the mo12 resistance gene). LMV was purified and LMV polyclonal antiserum was produced in rabbit by a series of intravenous and intramuscular injections, the titre of this antiserum was 1:1024. Gel double diffusion test (GDDT) was performed, and precipitin bands appeared. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting showed the presence of coat protein 29 kDa. In Immunocapture reverse transcription PCR (IC-RT-PCR) with a LMV specific primer pair, an aproximately 1300 bp fragment was amplified. Key words: Lettuce mosaic virus, Cucumber mosaic virus, Tomato spotted wilt virus, Immunocapture reverse transcription PCR, sodium dodecyl sulfate polyacrylamide gel electrophoresis.

First Report of Cucumber mosaic virus in Paeonia lactifera in France.

Chinese peony (Paeonia lactiflora Pall.), a hardy ornamental plant of the family Paeoniaceae cultivated in gardens and for cut flower production, is frequently infected by Tobacco rattle virus (TRV) in the field. The virus usually induces severe mosaic and chlorotic ringspot symptoms in the leaves, decreasing the commercial value of cut flowers. TRV is routinely detected by mechanical inoculation onto Nicotiana tabacum cv Xanthi, where it induces typical necrotic local ringspots in 3 to 7 days, followed by a reverse transcription (RT)-PCR test (2). In 2004, Xanthi test plants inoculated with sap extracts from 4 of 36 P. lactiflora cv. Odile plants grown in a field plot in the region of Hyères (southeast France) showed systemic mosaic symptoms in addition to the TRV-typical response. In each case, Cucumber mosaic virus (CMV) was detected by the reactions of a range of inoculated plants (1), the observation of 30 nm isometric particles in crude leaf extracts with the electron microscope, and by positive reactions in double antibody sandwich (DAS)-ELISAs with specific polyclonal antibodies. In double-immunodiffusion analysis, these isolates were shown to belong to the group II of CMV isolates (3). ELISA of the peony plants confirmed the presence of CMV and revealed two additional infected plants in the spring of 2006. Following isolation from local lesions on Vigna unguiculata and multiplication in Xanthi tobacco plants, one of the isolates was used to inoculate manually or with Myzus persicae aphids 10 CMV-free plants of P. lactiflora cv. Odile obtained from meristem culture. Three months postinoculation, only three of the aphid-inoculated plants were CMV positive by DAS-ELISA. No change was observed at 1 year postinoculation and no symptoms have been observed, even in CMV-infected plants. CMV appears to be latent in P. lactiflora, therefore detection of CMV before vegetative propagation of the plants is advised because of the risks of synergism for symptoms with other viruses such as TRV. To our knowledge this is the first report of CMV in peony.

First Report of Cucumber mosaic virus Infecting Pinewood Coneflower (Rudbeckia bicolor) in Korea

Department of Plant Medicine, Chungbuk National University, Cheongju 361-763, Korea(Received on December 21, 2009; Accepted on February 15, 2010)A virus isolate causing symptoms of yellow mosaic, fernleaves, malformation and plant necrosis on Rudbeckiabicolor was prevalent around Pyeongchang area inKorea. The causal virus was identified as Cucumbermosaic virus (CMV) using characteristics from bio-logical, serological and molecular analyses and namedas CMV-Rb. CMV-Rb caused mosaic on Nicotianabenthamiana, N. tabacum, Capsicum annuum, and Lyco-persicon esculentum. However, typical local lesions didnot develop on inoculated Pisum sativum, Cucurbitamoschata, Datura stramonium and Tetragonia expansaplants. Full-length genome sequences of CMV-RbRNAs 1, 2 and 3 were obtained using 12 primer pairs byRT-PCR analysis. The genome of CMV-Rb RNA seg-ments 1, 2, and 3 consists of 3363nt, 3049nt, and 2214ntin length, respectively. In order to ascertain their taxo-nomic identity, nucleotide and the deduced amino acidsequence analyses RNAs 1, 2 and 3 of CMV-Rb isolateswere conducted with previously reported sequences ofCMV strains and/or isolates. CMV-Rb RNAs showedabout 90 to 99% sequence identity to those of subgroupI strains suggesting that CMV-Rb is more closely relat-ed to CMV isolates belong to subgroup I. To our know-ledge, this is the first report of CMV on Rudbeckiabicolor in Korea.Keywords : CMV-Rb, phylogenetic analyses, Rudbeckiabicolor, subgroup ICucumber mosaic virus (CMV), the type member of thegenus Cucumovirus, infects more than 1,000 species ofplants and induces the typical mosaic symptoms in manyhost plants. Some of the intermediate symptoms, however,include blight, fernleaf, ringspot, and stunt. In Korea, atleast 109 natural host plant species has been reported, i.e.,20 in upland crops, 20 in vegetable crops, 28 in floral crops,acacia in wood, 40 in wild plants (List of plant disease inKorea, 2004, The Korean Society of Plant Pathology).Recently, CMV infections were also reported on Hydrangeamacrophylla (Lee et al., 2001), water chickweed (Choi etal., 2004), Isodon inflexus Kudo, Jeffersonia dubia Benth,Phryma leptostachya var. asiatica Hara (Lee et al., 2008).However, no natural outbreaks by CMV have been reportedon Rudbeckia bicolor, but Bidens mottle virus (BiMoV)was only identified (Brunt et al., 1996; Choi, 2001; Jin,2003; Lee, 1981; Lee et al., 2003; Logan et al., 1984).The genome of CMV consists of three genomic RNAs(RNA 1, 2 and 3; Roossinck, 2001). In infected host plants,it also produces two subgenomic RNAs (4 and 4A; Palukaitiset al., 1992). Based upon biological, serological, and, mole-cular biological characteristics of CMV isolates, they wereclassified into two subgroups, i.e., subgroup I and II (Owenand Palukaitis, 1988). The nucleotide sequence identitybetween subgroup I and II isolates range from 69 to 77%,while showing above 90% nucleotide sequence identitywithin each subgroup isolates. More detailed nucleotidesequence analyses, especially with the coat protein (CP)and 5' nontranslated region (NTR) of RNA 3 further sug-gested subdivision of subgroup I into subgroups IA and IB(Roossinck et al., 1999). This subgrouping was more clear-ly supported from the analysis of nucleotide sequences of1a and 3a open reading frames (ORFs) than those of the 2aand CP ORFs (Roossinck, 2002). In this paper, we reportthe biological and serological characteristics as well ascomplete nucleotide sequence analyses of CMV-Rb isolate.We believe this is the first report of natural CMV infectionon Rudbeckia bicolor in Korea.Pinewood coneflower (R. bicolor), family Asteraceae, iswidely grown as an ornamental crop and a wildflower. In2005, we could easily observe yellow mosaic, sometimes

Seed transmission of Cucumber mosaic virus in pepper

Infection caused by Cucumber mosaic virus (CMV) is one of the most important viral diseases of pepper worldwide. Young pepper seedlings were inoculated mechanically with CMV-Fny (Fast New York) isolate and were kept in growth chambers at 20–25 °C for symptom and fruit development. All inoculated plants developed severe mosaic symptoms and produced fruit except one. Mature seeds were isolated from fruits harvested from CMV-infected plants. Total RNA was extracted from pepper seeds and analyzed by reverse transcription-polymerase chain reaction (RT-PCR) using CMV sub-group IA specific primers. Analysis of individual whole seeds showed that seed-borne infection of CMV in pepper ranged from 95 to 100%. Further seed-growth tests were performed in Petri dishes and CMV was detected in both seed coat and embryo. Seed coat infection of CMV ranged from 53 to 83% while that of the embryo ranged from 10 to 46%. Seed-growth tests in pots were also performed and the rate of seed transmission was approximately 10 to 14%. This is the first report of CMV seed transmission in pepper.

First Report of Cucumber mosaic virus in Anemone sp. in the United States

In the spring of 2008, more than a dozen, aphid-infested, anemone plants (Anemone sp.) grown at the campus of the University of Arkansas in Fayetteville showed stunting and mosaic, whereas only two were asymptomatic. Leaf homogenates from four symptomatic plants were inoculated onto Nicotiana benthamiana that became stunted and developed severe mosaic approximately 7 days postinoculation, whereas buffer-inoculated plants remained asymptomatic. Double-stranded RNA (dsRNA) extraction (4) from symptomatic anemone revealed the presence of four predominant bands of approximately 3.2, 2.9, 2.2, and 0.9 kbp, a pattern indicative of cucumovirus infection. Cucumber mosaic virus (CMV) is the only cucumovirus reported in anemone in Europe (2) and Israel (3), and for this reason, anemone and N. benthamiana plants were tested by Protein A ELISA with antisera against CMV developed by H. A. Scott. ELISA verified the presence of CMV in symptomatic anemone and inoculated N. benthamiana, while asymptomatic plants were free of the virus. Using cucumovirus degenerate primers, essentially as described by Choi et al. (1), a region of approximately 940 bases that includes the complete coat protein gene of the virus was amplified from symptomatic anemone and N. benthamiana but not asymptomatic plants of either species. This anemone isolate (GenBank Accession No. FJ375723) belongs to the IA subgroup of CMV because it shares 99% nucleotide and 100% amino acid sequence identities with the Fny isolates of the virus. To my knowledge, this is the first report of CMV infecting anemone in the United States and an important discovery for the ornamental industry since anemone is commonly grown together with several ornamental hosts of CMV in nursery and garden settings.

First Report of Cucumber mosaic virus Infecting Solanum jasminoides in Italy.

Solanum jasminoides Paxton (potato vine or jasmine nightshade) is a vegetatively propagated ornamental species within the Solanaceae family. Recently, symptomless plants of this species were reported as natural hosts of the quarantine pest, Potato spindle tuber viroid (PSTVd) in Italy (1). In January 2008, approximately 1,000 potted, 2-year-old plants of S. jasminoides growing in an ornamental nursery in Sicily showed virus-like mosaic and malformation of leaves. Symptoms were observed on approximately 60% of the plants. Leaf tissue, collected from 30 symptomatic and 10 symptomless plants, was analyzed by double-antibody sandwich-ELISA with polyclonal antisera specific to Cucumber mosaic virus (CMV), Tomato spotted wilt virus, and Impatiens necrotic spot virus (Loewe Biochemica, Sauerlach, Germany). The same samples were also analyzed by tissue-printing hybridization with a PSTVd-specific digoxigenin-labelled riboprobe. All the symptomatic samples tested positive only with antisera against CMV, but negative in all other tests. The symptomless samples were negative in all the performed tests. To confirm the association of CMV with the diseased plants, total RNA was extracted from the same samples (RNeasy Plant Mini Kit; Qiagen, Hilden, Germany) and analyzed by reverse transcription (RT)-PCR using CMV-specific primers MP+5'-CATGGCTTTCCAAGGTACCAG-3' and MP-5'-CTAAAGACCGTTAACCACCTGC-3' that amplify a 844-bp fragment from the MP gene (2). The expected fragment was amplified only from samples of symptomatic tissue. CMV was also detected in mother plants grown in the same nursery and showing same mosaic symptoms. Definitive identification of the pathogen was obtained by cloning and sequencing the RT-PCR product. The obtained sequence (GenBank Accession No. EU828783) had 99 and 98% similarity with the subgroup I-A isolates CMV-LUN (GenBank Accession No. EU432183) and CMV-Fny (GenBank Accession No. DI0538), respectively. To our knowledge, this is the first report of CMV infecting S. jasminoides and it adds a new host to the more than 1,000 species (85 plant families) infected by this virus. The high incidence of the disease in the nursery could be due to propagation of cuttings from an infected source.

First Report of Cucumber mosaic virus on Jatropha curcas in India.

Jatropha curcas L. is a major commercial biodiesel fuel crop grown on 98 million acres (39.66 million ha) in India. Severe mosaic disease accompanied by yellow spots was noticed on 15% of J. curcas growing in the experimental plots of NBRI, Lucknow, India, during October of 2006. Inoculations with sap from symptomatic plants resulted in systemic mosaic on three of seven J. curcas seedlings. Gel diffusion tests were performed with antiserum to Cucumber mosaic virus (CMV), Tobacco ringspot virus, and Chrysanthemum virus B (PVAS-242a, PVAS-157, and PVAS-349, respectively; ATCC, Manassas, VA). Leaf sap of infected plants reacted only with PVAS-242a, indicating the presence of CMV. Reverse transcription (RT)-PCR assays with CMV coat protein gene specific primers (Genbank Accession Nos. AM180922 and AM180923) and total nucleic acid extracted from symptomatic J. curcas leaf tissue yielded the expected ~650-bp amplicon, which was cloned and sequenced (GenBank Accession No. EF153739). BLAST analysis indicated 98 to 99% nucleotide identity with CMV isolates (GenBank Accession Nos. DQ914877, DQ640743, AF350450, AF281864, X89652, AF198622, DQ152254, DQ141675, and DQ028777). Phylogenetic analysis showed that the J. curcas isolate was more closely related to Indian isolates of CMV belonging to subgroup Ib. Literature surveys revealed records of Jatropha mosaic virus on J. gossypiifolia in Puerto Rico (1) and on J. curcas in India (2). To our knowledge, this is the first report of CMV on J. curcas.

First Report of Cucumber mosaic virus in Echium candicans in France.

Echium candicans (Linn.) Herb. Banks (Pride of Madeira or Viper's Bugloss), family Boraginaceae, is a perennial shrub used in gardens for the ornamental quality of its deep blue inflorescences, especially in coastal areas near the Mediterranean Sea. Mosaic symptoms were observed in leaves of E. candicans in the Alpes Maritimes Department of southeastern France, St Jean Cap Ferrat in 1994, Menton in 2002, and Antibes in 2005. Symptoms exhibited in a range of inoculated plants including Nicotiana tabacum cvs. Xanthi and Samsun, Chenopodium quinoa, C. amaranticolor, Vigna unguiculata cv. Black, and Cucumis sativus cv. Poinsett were typical of Cucumber mosaic virus (CMV). Occurrence of CMV in one sample from each of the three localities was confirmed by the observation of isometric particles (approximately 30 nm) with the electron microscope in crude sap preparations from the infected plants, positive reactions in double-antibody sandwich (DAS)-ELISA to polyclonal antibodies raised against CMV (1), and the nonpersistent transmission of the virus from infected Xanthi to virus-free Xanthi plants by Myzus persicae. In double-immunodiffusion analysis, the three isolates were shown to belong to the CMV subgroup II (1,2). To determine if CMV was responsible for the symptoms observed, the isolate from Antibes was multiplied in Xanthi plants after isolation from local lesions on V. unguiculata and mechanically inoculated to 3-year-old plants of E. candicans tested to be free from CMV before the mechanical inoculation. One month after inoculation, mild mosaic symptoms were observed in young leaves and CMV was detected by DAS-ELISA in 10 of 10 inoculated plants. To our knowledge, this is the first report of CMV in E. candicans.

First Report of Cucumber mosaic virus in Viola hederacea in France and Italy.

Viola hederacea Labill. (Australian violet or trailing violet), family Violaceae, is native to eastern Australia and used for its ornamental quality in humid conditions, especially in terrariums. Mosaic and chlorotic ringspots associated with a mild crinkling on leaves of V. hederacea were observed in gardens in southeast France and La Mortola, Italy in 2001 and 2003, respectively. These symptoms were different from the small chlorotic spots reported in the same species in Queensland, Australia, from which a rhabdovirus was isolated (1). In samples collected from both locations, presence of Cucumber mosaic virus (CMV) was suspected on the basis of the symptoms exhibited by a range of inoculated plants (2) and the observation of isometric particles of approximately 30 nm with the electron microscope in sap preparations. This was confirmed by positive reactions with CMV polyclonal antiserum (3) in double-antibody sandwich-ELISA. Because of the viscosity of the V. hederacea extracts, 0.01% (w/v) of pectolyase in phosphate buffer was used to grind the samples and the homogenate was kept at room temperature for 2 h. In double-immunodiffusion analysis, each isolate was shown to belong to the group II of CMV. Tomato strains D and To were used as positive controls for CMV groups I and II, respectively. The virus was transmitted by aphids (Myzus persicae) in a nonpersistent manner from infected Nicotiana tabacum cv. Xanthi-nc plants to healthy Xanthi-nc plants. To determine if CMV was responsible for the symptoms observed, the French and Italian isolates were multiplied in Xanthi-nc tobacco plants after isolation from local lesions on Vigna unguiculata and mechanically inoculated to 10 plants of V. hederacea. A systemic vein clearing developed on leaves 10 days after inoculation, followed by mosaic and crinkling. CMV was detected in each plant 3 weeks after inoculation. To our knowledge, this is the first report of CMV in V. hederacea in France and Italy.

Brief Note: Natural infection of Viola cornuta (Violaceae) with Cucumber mosaic virus, subgroup I

Plants of Viola cornuta displaying typical virus symptoms were observed during spring 2003 in a plant nursery in Córdoba, central Argentina. Electron microscopic examinations of symptomatic leaf samples revealed the presence of isometric virus-like particles about 30 nm in diameter. Subsequent serological analysis allowed the identification of the pathogen as a subgroup I strain of Cucumber mosaic virus (CMV). These results were confirmed by antigen capture--reverse transcription--polymerase chain reaction with specific CMV primers, and digestion with a restriction enzyme. This is the first report of CMV infecting V. cornuta in Argentina.

First Report of Cucumber mosaic virus in Eryngium yuccifolium (Rattlesnake Master) in Ohio.

Rattlesnake master (Eryngium yuccifolium) is a wildflower that is native to Ohio. In recent years, native wildflowers have become very popular with home gardeners, and conservationists have begun to reestablish these plants in their native ranges. As native perennial wildflowers become more common, it is important to determine if they might serve as possible perennial reservoirs of viruses. A plot of 20 species native to Ohio was established on the Waterman Agricultural and Natural Resources Laboratory, The Ohio State University, Columbus, Ohio. In the summers of 1999 and 2001, random samples were collected from established plantings. Some sampled plants did not show symptoms of virus infection; however, all samples of E. yuccifolium appeared chlorotic, slightly mottled, and stunted. Using double-stranded RNA (dsRNA) analysis (1), these plants were assayed for viral infection. dsRNA profiles obtained from symptomatic E. yuccifolium resembled that of Cucumber mosaic virus (CMV). These results were confirmed with an enzyme-linked immunosorbent assay (ELISA; Agdia Inc., Elkhart, IN) for CMV. dsRNA-containing samples of E. yuccifolium produced ELISA absorbance values (A405) of 0.231 to 0.713 when compared with the negative control. All 14 samples of E. yuccifolium tested positive for CMV. To our knowledge, this is the first report of CMV in E. yuccifolium, which should serve as the basis for a more extensive survey, since CMV can potentially infect a wide variety of ornamental and nonornamental hosts. Reference: (1) R. Valverde et al. Plant Dis. 74:255, 1990.

Occurrence of Cucumber mosaic virus in Gerbera jamesonii in India

Gerbera jamesonii (family Asteraceae) is a popular perennial ornamental cut flower and potted plant with considerable economic importance. In a survey of gerbera grown in floriculture fields at the Institute of Himalayan Bioresource Technology (IHBT), Palampur and nearby nurseries, color break symptoms on the petals, asymmetrical ray florets, and deformed flowers were observed during 2003-2004. The virus evoked chlorotic local lesions on Chenopodium album, C. amaranticolor, and C. quinoa, while systemic mosaic was observed on Cucumis sativus, Nicotiana benthamiana, N. clevelandii, N. glutinosa, and N. tabacum cv. Samsun. The virus was transmitted nonpersistently by Myzus persicae and Aphis gossypii and was identified as Cucumber mosaic virus (CMV) using enzyme-linked immunosorbent assay (ELISA) with CMV-specific antibodies (Agdia, Elkhart, IN). Polyhedral particles approximately 29 nm were observed with electron microscopy of leaf dips from symptomatic gerbera leaves. Total RNA was isolated from the infected gerbera plants and N. glutinosa by using RNAqueous (Ambion, Austin, TX). CMV-specific primers (1) were used to detect the virus with reverse transcription-polymerase chain reaction that produced an amplicon predicted size of approximately 540 bp, but the virus was not detected in healthy controls. Sequence alignment of the amplicons (533 bp) utilizing BLAST resulted in 91 to 99% homology with the partial intercistronic region and partial coat protein gene (1042-1574 bp) (gene sequence submitted to EMBL database with Accession no. AJ634532) of CMV RNA3 in subgroup I. To our knowledge, this is the first report of CMV on gerbera in India. Reference: (1) C. De Blas et al. J. Phytopathol. 141:323, 1994.

Polygala myrtifolia as a New Natural Host of Cucumber mosaic virus.

Cucumber mosaic virus (CMV), Tomato spotted wilt virus (TSWV), and Impatiens necrotic spot virus (INSV) are among the most important viral pathogens of ornamental plants (1). Polygala myrtifolia L. (myrtle-leaf milkwort), originating from South Africa, and a member of the Polygalaceae, was recently introduced in Italy as a cultivated ornamental shrub for its fast and attractive free-flowering growth and drought-resistant characteristics. It can become an invasive plant and is now considered a serious problem in coastal areas of Australia where it was introduced as a garden plant. In Italy, P. myrtifolia is propagated by cuttings in commercial nurseries during the summer. In the winter of 2002, plants of P. myrtifolia growing in pots in an ornamental nursery in Sicily showed virus-like mosaic and malformation of leaves that appeared lanceolate with a lack of flowering. Leaf tissue was analyzed by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) with polyclonal antisera to CMV, TSWV (Lettuce type), and INSV. Positive ELISA results were obtained only with the CMV polyclonal antisera. Complete remission of symptoms was observed on new flushes after pruning and incubation of infected plants at warm temperatures (30 and 20°C, day and night, respectively). This evidence led to the hypothesis that the disease or virus was disseminated by transportation and propagation of plants without visible symptoms during the hot season. A survey was also performed in two historical gardens of Catania (Sicily) where a group of apparently healthy P. myrtifolia plants, from the previously mentioned ornamental nursery in Sicily, were introduced as a single specimen or to form a hedge. These plants showed the same leaf malformations and mosaic symptoms observed in the nursery. DAS-ELISA confirmed the presence of CMV but not TSWV and INSV. To our knowledge, this is the first report of CMV on P. myrtifolia and it adds a new host to over 1,000 species (85 plant families) infected by this virus. Reference: (1) M. L. Daughtrey et al. Plant Dis. 81:1220, 1997.

First Report of a Cucumber mosaic virus-Associated Satellite RNA in Lobelia erinus.

Lobelia (Lobelia erinus L.) is a common herbaceous annual used in flower beds and hanging baskets. The plant blooms from early to late summer. In the summer of 2000, Lobelia plants expressing virus-like symptoms were collected from a greenhouse-based production site in Ohio. Affected plants expressed a mild leaf mosaic and stunting. Viral-associated dsRNA was isolated from 7 g of symptomatic leaf tissue (1). Four dsRNAs were observed at 3.9, 3.0, 2.25, and 1.05 kb indicating the presence of a Cucumovirus. A fifth dsRNA at 0.75 kb also was observed, consistent with the presence of a satellite RNA. Enzyme-linked immunosorbent assay (ELISA) analysis (Agdia, Inc., Elkhart, IN) of symptomatic Lobelia tissue confirmed the presence of Cucumber mosaic virus (CMV). A (S)CARNA-5 (-) cDNA clone (American Type Culture Collection #45124) was labeled with digoxygenin (DIG) as per the manufacturer's instructions (Genius II DIG-DNA Labeling Kit, Boehringer Mannheim) and used as a diagnostic probe to detect this satellite RNA. Northern hybridization confirmed the identity of the satellite RNA (2). This is the first report of any satellite RNA associated with a virus infection in Lobelia and the first report of CMV in this host in Ohio.