First Report of Apium virus Y on Cilantro, Celery, and Parsley in California

Recently, Apium virus Y (ApVY) was detected in field-grown cilantro (Coriandrum sativum), celery (Apium graveolens), and parsley (Petroselinum crispum) in California. In 2003, cilantro plants growing in three different fields in California (Monterey, San Joaquin, and San Luis Obispo counties) expressed symptoms of mosaic, vein clearing, and stunting. When plant sap was examined by transmission electron microscopy, flexuous, rod-shaped virus particles were observed. Total RNA was extracted from the symptomatic cilantro plants and used as a template in reverse transcription (RT)-PCR using universal potyvirus primers according to Chen et al. (1). The RT-PCR product was cloned into pGEM-T (Promega, Madison, WI) and the insert of 1,713 bp was sequenced (GenBank Accession No. EU515125). Nucleotide sequences from clones derived from three different infected cilantro plants were 89 to 97% identical to ApVY sequences encoding partial sequence of polyprotein in GenBank (Accession Nos. AY049716, EU127499, AF207594, AF203529, and EU255632). In 2007, celery plants showing necrotic line patterns and necrotic lesions on lower leaves and petioles were observed in several fields in two coastal counties in California (Monterey and Santa Clara counties). Flexuous, rod-shaped virus particles were also observed in the sap of those plants. ELISA for Cucumber mosaic virus and RT-PCR for Celery mosaic virus were negative. ApVY specific primers were designed on the basis of a consensus sequence of ApVY identified from cilantro in 2003; reverse primer 5′-GGCTCTTGCTATAGACAAATAGT-3′ and forward primer 5′-GAAGACCAAGCCAATGTGTGTA-3′. The sequence of RT-PCR products (GenBank Accession No. EU515126) amplified from infected celery had 90 to 98% nucleotide identity to ApVY. When the deduced amino acid sequences of NIb and CP regions from both cilantro and celery were used for comparison, they showed 95 to 99% identity with the known ApVY GenBank sequences mentioned above. More than 10 asymptomatic parsley plants growing in fields adjacent to the infected celery were also tested for ApVY and found to be infected. ApVY was previously identified in three Apiaceae weeds in Australia (2) and in celery in New Zealand (3). To our knowledge, this is the first report of ApVY on cilantro, celery, and parsley in California. References: (1) J. Chen et al. Arch. Virol. 146:757, 2001. (2) J. Moran et al. Arch. Virol. 147:1855, 2002. (3) J. Tang et al. Plant Dis. 91:1682, 2007.

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First Report of Catharanthus mosaic virus in Mandevilla in the United States

Plant Disease ◽

10.1094/pdis-09-14-0913-pdn ◽

2015 ◽

Vol 99 (1) ◽

pp. 165-165 ◽

Cited By ~ 4

Author(s):

D. Mollov ◽

M. A. Guaragna ◽

B. Lockhart ◽

J. A. M. Rezende ◽

R. Jordan

Keyword(s):

United States ◽

Amino Acid ◽

Mosaic Virus ◽

Consensus Sequence ◽

The United States ◽

Amino Acid Sequences ◽

Universal Primers ◽

Rt Pcr ◽

First Report ◽

Virus Particles

Mandevilla (Apocynaceae) is an ornamental tropical vine popular for its bright and attractive flowers. During 2012 to 2013, 12 Mandevilla sp. samples from Minnesota and Florida nurseries were submitted for analysis at the University of Minnesota Plant Disease Clinic. Plants showed mosaic symptoms, leaf deformation, premature leaf senescence, and vine dieback. Filamentous virus particles with modal lengths 700 to 900 nm were observed by transmission electron microscopy (TEM) in partially purified preparations from symptomatic leaves. Partially purified virions were obtained using 30% sucrose cushion centrifuged at 109,000 gmax for 2 h at 10°C (5). No other virus particles were observed in these samples, nor were any observed in non-symptomatic samples. One sample was submitted as potted plant (Mandevilla ‘Sunmandeho’ Sun Parasol Giant White) and was kept under greenhouse conditions for subsequent analyses. Total RNA (Qiagen) was extracted from this sample, and Potyvirus was detected using the universal primers Poty S (5′-GGN AAY AAY AGY GGN CAR CC-3′) and PV1 (5′-20(T)V-3′) (1) by reverse transcription (RT)-PCR (3). The amplified product was the expected ~1.7-kb, corresponding to the partial nuclear inclusion body gene, the coat protein (CP) gene, and the 3′ end untranslated region. The RT-PCR amplicon was cloned (NEB) and sequenced, and the 1,720-bp consensus sequence was deposited in GenBank (Accession No. KM243928). NCBI BLAST analysis at the nucleotide level revealed highest identity (83%) with an isolate of Catharanthus mosaic virus (CatMV) from Brazil (Accession No. DQ365928). Pairwise analysis of the predicted 256 amino acid CP revealed 91% identity with the CatMV Brazilian isolate (ABI94824) and 68% or less identity with other potyviruses. Two potyviruses are usually considered the same species if their CP amino acid sequences are greater than 80% identical (2). Serological analysis of the infected sample Mandevilla ‘Sunmandeho’ Sun Parasol Giant White using a CatMV specific antiserum (4) resulted in positive indirect ELISA reactions. CatMV has been previously reported in periwinkle (Catharanthus roseus) in Brazil (4). Based on the analyses by TEM, RT-PCR, nucleotide and amino acid sequence identities, and serological reactivity, we identify this virus as a U.S. Mandevilla isolate of CatMV. To our knowledge, this is the first report of Catharanthus mosaic virus both in the United States and in Mandevilla. References: (1) J. Chen et al. Arch Virol. 146:757, 2001. (2) A. Gibbs and K. Ohshima. Ann. Rev. Phytopathol. 48:205, 2010. (3) R. L. Jordan et al. Acta Hortic. 901:159, 2011. (4) S. C. Maciell et al. Sci. Agric. Piracicaba, Brazil. 68:687, 2011. (5) D. Mollov et al. Arch Virol. 158:1917, 2013.

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First report of dasheen mosaic virus infecting taro (Colocasia esculenta) in Louisiana

Plant Disease ◽

10.1094/pdis-04-21-0854-pdn ◽

2021 ◽

Author(s):

Cesar Escalante ◽

David Galo ◽

Rodrigo Diaz ◽

Rodrigo Valverde

Keyword(s):

United States ◽

Mosaic Virus ◽

Consensus Sequence ◽

The United States ◽

Colocasia Esculenta ◽

Rt Pcr ◽

Serological Tests ◽

First Report ◽

Pcr Products ◽

The University

Taro [Colocasia esculenta (L.) Schott], also called dasheen or malanga is an important staple crop in many tropical and subtropical countries (Chaïr et al. 2016). In October 2020, taro plants showing foliar symptoms consisting of mosaic, feathery mottle, and vein clearing patterns were observed in the Hilltop Arboretum, the Bluebonnet Swamp Nature Center, the Louisiana State University Agricultural Center Botanic Gardens, and the University Lake, in Baton Rouge, Louisiana. Unidentified aphids were also observed infesting the plants showing the described symptoms. From each location, two foliar samples from symptomatic and two from asymptomatic plants were collected and tested by ELISA using antiserum for general potyvirus group (Agdia, Elkhart, IN). Seven of eight symptomatic samples tested positive while the asymptomatic samples were negative. The seven positive samples were used to perform an additional ELISA test using antiserum specific for dasheen mosaic virus (DsMV) (Agdia). All seven samples tested positive for DsMV. To confirm the identity of the virus, total RNA was extracted from the seven samples using the PureLink® Plant RNA Reagent Kit (Invitrogen, Carlsbad, CA). After DNA digestion with PerfeCta® DNase I (Qiagen, Beverly, MA), the RNA was used to perform reverse transcription polymerase chain reaction (RT-PCR) with primer set DMV 5708-5731-F/DMV 6131-6154-R which is specific for DsMV (Wang et al. 2017). RT-PCR was performed using the AccessQuickTM RT-PCR System (Promega, Madison, WI) following the reaction conditions described by Wang et al. PCR products of the expected size (~447 bp) were obtained with all seven samples and were Sanger-sequenced. A consensus sequence (MW284936) was obtained with the two sequences from samples collected at the University Lake and aligned with other sequences available in the GenBank using BLASTn. Our isolate of DsMV showed 90.6% nt identity to an isolate of DsMV from Ethiopia (MG602229). Mechanical inoculations to healthy taro plants were conducted using leaf tissue of symptomatic plants as source of inoculum. Inoculated plants exhibited mosaic symptoms three weeks after inoculation and were ELISA-positive for DsMV. Symptomatology, serological tests, RT-PCR testing, and DNA sequencing of RT-PCR products support that the symptomatic taro plants were infected with DsMV. Taro is a crop in Hawaii, but in the contiguous United States, it is mostly grown as an ornamental and is considered an invasive species. Its distribution is restricted to the southern continental states and Hawaii (Cozad et al. 2018). CABI, EPPO (1998) lists the presence of DsMV in several states of the United States, including Louisiana; however, there is no record in the literature of the identification of this virus in Louisiana. The potential impact of DsMV in taro and related ornamental species in southern United States is unknown. To the best of our knowledge, this is the first report documenting DsMV infecting taro in Louisiana.

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First Report of Yam mild mosaic virus in Yam in Guangxi Province, China

Plant Disease ◽

10.1094/pdis-04-11-0350 ◽

2011 ◽

Vol 95 (10) ◽

pp. 1320-1320 ◽

Cited By ~ 4

Author(s):

C. Zou ◽

J. Meng ◽

Z. Li ◽

M. Wei ◽

J. Song ◽

...

Keyword(s):

Mosaic Virus ◽

Viral Genome ◽

Terminal Region ◽

Mild Mosaic ◽

Rt Pcr ◽

Degenerate Primers ◽

Germplasm Exchange ◽

First Report ◽

Pcr Products ◽

Mild Mosaic Virus

Yams (Dioscorea spp.) are widely grown in China as vegetables and herbal medicine. However, studies on viral diseases on yams are still limited. As a pilot project of a government initiative for improving yam productivity, a small study was conducted in Guangxi, a southern province of China, on viral disease in yams. Incidence of virus-like disease for the three extensively grown D. alata cultivars, GH2, GH5, and GH6, were 12 to 40%, 12 to 29%, and 11 to 25%, respectively, as found in a field survey with a five-plot sampling method in 2010. A total of 112 leaf samples showing mosaic or mottling or leaves without symptoms were collected from the cvs. GH2, GH5, GH6, and seven additional cultivars (D. alata cvs. GY2, GY23, GY47, GY69, GY62, GY72, and D. batatas cv. Tiegun). To determine if the symptoms were caused by Yam mild mosaic virus (YMMV; genus Potyvirus, family Potyviridae), total RNA was extracted from leaves with a commercial RNA purification kit (TIANGEN, Beijing, China), and reverse-transcription (RT)-PCR was conducted with a YMMV-specific primer pair (4) that amplifies the 3′-terminal portion of the viral genome. A PCR product with the predicted size of 262 bp was obtained from samples of GH5 (number testing positive of total number of leaves = 5 of 12), GH6 (24 of 42), and GY72 (1 of 1), but not from asymptomatic leaves. PCR products from a GH5 sample (YMMV-Nanning) and a GH6 sample (YMMV-Luzhai) were cloned and sequenced using an ABI PRISM 3770 DNA Sequencer. The two PCR products were 97% identical at nucleotide (nt) level and with the highest homology (89% identity) to a YMMV isolate (GenBank Accession No. AJ305466). To further characterize the isolates, degenerate primers (2) were used to amplify viral genome sequence corresponding to the C-terminal region of the nuclear inclusion protein b (NIb) and the N-terminal region of the coat protein (CP). These 781-nt fragments were sequenced and a new primer, YMMV For1 (5′-TTCATGTCGCACAAAGCAGTTAAG-3′) corresponding to the NIb region, was designed and used together with primer YMMV UTR 1R to amplify a fragment that covers the complete CP region of YMMV by RT-PCR. These 1,278-nt fragments were sequenced (GenBank Accession Nos. JF357962 and JF357963). CP nucleotide sequences of the YMMV-Nanning and YMMV-Luzhai isolates were 94% similar, while amino acid sequences were 99% similar. BLAST searches revealed a nucleotide identity of 82 to 89% and a similarity of 88 to 97% for amino acids to sequences of YMMV isolates (AF548499 and AF548519 and AAQ12304 and BAA82070, respectively) in GenBank. YMMV is known to be prevalent on D. alata in Africa and the South Pacific, and has recently been identified in the Caribbean (1) and Colombia (3). To our knowledge, this is the first report of the natural occurrence of YMMV in China and it may have implications for yam production and germplasm exchange within China. References: (1) M. Bousalem and S. Dallot. Plant Dis. 84:200, 2000. (2) D. Colinet et al. Phytopathology 84:65, 1994. (3) S. Dallot et al. Plant Dis. 85:803, 2001. (4) R. A. Mumford and S. E. Seal. J. Virol. Methods 69:73, 1997.

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First Report of Tomato Brown Rugose Fruit Virus Infecting Tomato Crop in Saudi Arabia

Plant Disease ◽

10.1094/pdis-05-21-1065-pdn ◽

2021 ◽

Author(s):

Ahmed Sabra ◽

Mohammed Ali Al Saleh ◽

I. M. Alshahwan ◽

Mahmoud A. Amer

Keyword(s):

Saudi Arabia ◽

Mosaic Virus ◽

Solanum Lycopersicum ◽

Tomato Mosaic Virus ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

First Report ◽

Pcr Products ◽

Dark Green ◽

Leaf Symptoms

Tomato (Solanum lycopersicum L.) is the most economically important member of family Solanaceae and cultivated worldwide and one of the most important crops in Saudi Arabia. The aim of this study is screening of the most common viruses in Riyadh region and identified the presence of tomato brown rugose fruit virus (ToBRFV) in Saudi Arabia. In January 2021, unusual fruit and leaf symptoms were observed in several greenhouses cultivating tomatoes commercially in Riyadh Region, Saudi Arabia. Fruit symptoms showed irregular brown spots, deformation, and yellowing spots which render the fruits non-marketable, while the leaf symptoms included mottling, mosaic with dark green wrinkled and narrowing. These plants presented the symptoms similar to those described in other studies (Salem et al., 2015, Luria et al., 2017). A total 45 Symptomatic leaf samples were collected and tested serologically against suspected important tomato viruses including: tomato chlorosis virus, tomato spotted wilt virus, tomato yellow leaf curl virus, tomato chlorotic spot virus, tomato aspermy virus, tomato bushy stunt virus, tomato black ring virus, tomato ringspot virus, tomato mosaic virus, pepino mosaic virus and ToBRFV using Enzyme linked immunosorbent assay (ELISA) test (LOEWE®, Biochemica, Germany), according to the manufacturers' instructions. The obtained results showed that 84.4% (38/45) of symptomatic tomato samples were infected with at least one of the detected viruses. The obtained results showed that 55.5% (25/45) of symptomatic tomato samples were found positive to ToBRFV, three out of 25 samples (12%) were singly infected, however 22 out of 45 (48.8%) had mixed infection between ToBRFV and with at least one of tested viruses. A sample with a single infection of ToBRFV was mechanically inoculated into different host range including: Chenopodium amaranticolor, C. quinoa, C. album, C. glaucum, Nicotiana glutinosa, N. benthamiana, N. tabacum, N. occidentalis, Gomphrena globosa, Datura stramonium, Solanum lycopersicum, S. nigrum, petunia hybrida and symptoms were observed weekly and the systemic presence of the ToBRFV was confirmed by RT-PCR and partial nucleotide sequence. A Total RNA was extracted from DAS-ELISA positive samples using Thermo Scientific GeneJET Plant RNA Purification Mini Kit. Reverse transcription-Polymerase chain reaction (RT-PCR) was carried out using specific primers F-3666 (5´-ATGGTACGAACGGCGGCAG-3´) and R-4718 (5´-CAATCCTTGATGTG TTTAGCAC-3´) which amplified a fragment of 1052 bp of Open Reading Frame (ORF) encoding the RNA-dependent RNA polymerase (RdRp). (Luria et al. 2017). RT-PCR products were analyzed using 1.5 % agarose gel electrophoresis. RT-PCR products were sequenced in both directions by Macrogen Inc. Seoul, South Korea. Partial nucleotide sequences obtained from selected samples were submitted to GenBank and assigned the following accession numbers: MZ130501, MZ130502, and MZ130503. BLAST analysis of Saudi isolates of ToBRFV showed that the sequence shared nucleotide identities ranged between 98.99 % to 99.50 % among them and 98.87-99.87 % identity with ToBRFV isolates from Palestine (MK881101 and MN013187), Turkey (MK888980, MT118666, MN065184, and MT107885), United Kingdom (MN182533), Egypt (MN882030 and MN882031), Jordan (KT383474), USA (MT002973), Mexico (MK273183 and MK273190), Canada (MN549395) and Netherlands (MN882017, MN882018, MN882042, MN882023, MN882024, and MN882045). To our knowledge, this is the first report of occurrence of ToBRFV infecting tomato in Saudi Arabia which suggests its likely introduction by commercial seeds from countries reported this virus and spread in greenhouses through mechanical means. The author(s) declare no conflict of interest. Keywords: Tomato brown rugose fruit virus, tomato, ELISA, RT-PCR, Saudi Arabia References: Luria N, et al., 2017. PLoS ONE 12(1): 1-19. Salem N, et al., 2015. Archives of Virology 161(2): 503-506. Fig. 1. Symptoms caused by ToBRFV showing irregular brown spots, deformation, yellowing spots on fruits (A, B, C) and bubbling and mottling, mosaic with dark green wrinkled and narrowing on leaf (D).

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First Report of Cucumber mosaic virus Subgroup IA Isolate Infecting Yucca aloifolia in Italy

Plant Disease ◽

10.1094/pdis-03-14-0324-pdn ◽

2014 ◽

Vol 98 (9) ◽

pp. 1284-1284 ◽

Cited By ~ 1

Author(s):

G. Parrella ◽

B. Greco

Keyword(s):

Cucumber Mosaic Virus ◽

Mosaic Virus ◽

Reverse Transcription ◽

Ornamental Plants ◽

Aphid Transmission ◽

Rt Pcr ◽

Cmv Infection ◽

Campania Region ◽

First Report ◽

Pcr Products

Yucca aloifolia L. (Spanish bayonet), family Asparagaceae, is the type species of the genus Yucca. It is native to Mexico and the West Indies and is appreciated worldwide as an ornamental plant. In 2013, during a survey for viruses in ornamental plants in the Campania region of southern Italy, symptoms consisting of bright chlorotic spots and ring spots 1 to 3 mm in diameter with some necrotic streaks were observed on leaves of two plants of Y. aloifolia growing in a nursery located in the Pignataro Maggiore municipality, Caserta Province. Cucumber mosaic virus (CMV) infection was suspected because the symptoms resembled those caused by CMV in Yucca flaccida (1). A range of herbal plant indicators was inoculated with sap extracts of symptomatic Y. aloifolia plants and developed symptoms indicative of CMV. Furthermore, 30 nm isometric virus particles were observed in the same Y. aloifolia sap extracts by transmission electron microscopy. The identity of the virus was confirmed by positive reaction in ELISA tests with CMV polyclonal antisera (Bioreba) conducted on sap extracts of symptomatic Y. aloifolia plants and systemically infected symptomatic hosts (i.e., Nicotiana tabacum, N. glutinosa, Cucumber sativus cv. Marketer, Solanum lycopersicum cv. San Marzano). The presence of CMV in the two naturally infected Y. aloifolia and other mechanically inoculated plants was further verified by reverse transcription (RT)-PCR. Total RNAs were extracted with the E.Z.N.A. Plant RNA Kit (Omega Bio-Tek), according to the manufacturer's instructions. RT-PCR was carried out with the ImProm-II Reverse Transcription System first-strand synthesis reaction (Promega) using the primer pair CMV1 and CMV2 (2). These primers amplify part of the CP gene and part of the 3′-noncoding region of CMV RNA3 and were designed to produce amplicons of different sizes to distinguish CMV isolates belonging to subgroups I or II (3). RT-PCR products were obtained from both naturally infected Y. aloifolia and mechanically inoculated plants as well as from PAE1 isolate of CMV (2), used as positive control, but not from healthy plants. Based on the length of the amplicons obtained (487 bp), the CMV isolate from Y. aloifolia (named YAL) belonged to subgroup I (3). The amplified RT-PCR products were purified with QIAquick PCR Purification Kit (Qiagen), cloned in the pGEMT vector (Promega), and three independent clones were sequenced at MWG (Ebersberg, Germany). Sequences obtained from the two CMV-infected Y. aloifolia plants were identical. This sequence was deposited at GenBank (Accession No. HG965199). Multiple alignments of the YAL sequence with sequences of other CMV isolates using MEGA5 software revealed highest percentage of identity (98.9%) with the isolates Z (AB369269) and SO (AF103992) from Korea and Japan, respectively. Moreover, the YAL isolate was identified as belonging to subgroup IA, based on the presence of only one HpaII restriction site in the 487-bp sequence, as previously proposed (2). Although CMV seems to not be a major threat currently for the production of Y. aloifolia, because the farming of this plant is performed using vegetative propagation, particular attention should be given to the presence of the virus in donor mother plants in order to avoid the dispersion of infected plants that could serve as sources for aphid transmission to other susceptible plant species. To our knowledge, this is the first report of CMV infection of Y. aloifolia in the world. References: (1) I. Bouwen et al. Neth. J. Plant Pathol. 84:175, 1978. (2) G. Parrella and D. Sorrentino. J. Phytopathol. 157:762, 2009. (3) Z. Singh et al. Plant Dis. 79:713, 1995.

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First Report of Lettuce big-vein associated virus (Varicosavirus) Infecting Lettuce in Mexico

Plant Disease ◽

10.1094/pdis-07-13-0761-pdn ◽

2014 ◽

Vol 98 (4) ◽

pp. 573-573 ◽

Cited By ~ 3

Author(s):

D. L. Ochoa-Martínez ◽

J. Alfonsina-Hernández ◽

J. Sánchez-Escudero ◽

D. Rodríguez-Martínez ◽

J. Vera-Graziano

Keyword(s):

Mosaic Virus ◽

Consensus Sequence ◽

Leaf Tissue ◽

Plant Viruses ◽

Australian Isolate ◽

Healthy Plant ◽

Rt Pcr ◽

First Report ◽

Chlorotic Spot ◽

Spanish Isolate

Lettuce (Lactuca sativa) is a common consumed vegetable and a major source of income and nutrition for small farmers in Mexico. This crop is infected with at least nine viruses: Mirafiori lettuce big-vein virus (MiLBVV), Lettuce big-vein associated virus (LBVaV), both transmitted by the soil-borne fungus Olpidium brassicae; Tomato spotted wilt virus (TSWV), Tomato chlorotic spot virus (TCSV), Groundnut ringspot virus (GRSV), Lettuce mottle virus (LMoV), Cucumber mosaic virus (CMV), Bidens mosaic virus (BiMV), and Lettuce mosaic virus (LMV) (1). From March to May 2012, a disease on lettuce was observed in the south region of Mexico City displaying mild to severe mosaic, leaf deformation, reduced growth, slight thickening of the main vein, and plant death. At the beginning of the epidemic there were just a few plants with visible symptoms and 7 days later the entire crop was affected, causing a loss of 93% of the plants. It was estimated by counting the number of severely affected or dead plants in three plots. No thrips, aphids, or whiteflies were observed in the crop during this time. Twenty plants with similar symptoms were collected and tested by RT-PCR using the primers LBVaVF 5′-AACACTATGGGCATCCACAT-3′ and LBVaVR 5′-GCATGTCAGCAATCAGAGGA-3′ specific for the coat protein gene of LBVaV, amplifying a 322-bp fragment. Primers CP829F 5′-CCWACTTCATCAGTTGAGCGCTG-3′ and CP1418R 5′-TATCAGCTCCCTACACTATCCTCGC-3′ were used to detect MiLBVV (2). No amplification was obtained for MiLBVaV in any plants tested. PCR products of approximately 300 bp were obtained from four out of 20 symptomatic lettuce samples tested for LBVaV, but not from healthy plant and water controls. These results suggest the presence of another virus in symptomatic lettuce plants. Amplicons were gel-purified and sequenced using LBVaVF and LBVaVR primers. A consensus sequence was generated using the Bioedit v. 5 program. Both sequences of these Mexican lettuce isolates were 100% identical (Accession Nos. KC776266.1 and KC776267.1) and had identities between 94 and 99% to all sequences of LBVaV available in GenBank. Additionally, when alignments were made using ClustalW, these sequences showed identities of 99.7% to Almeria-Spanish isolate (Accession No. AY581686.1); 99.4% to Granada-Spanish isolate (AY581689.1); 99.1% to Dutch isolate (JN710441.1), Iranian isolate (JN400921.1), Australian isolate (GU220725.1), Brazilian isolate (DQ530354.1), England isolate (AY581690.1), and American isolate (AY496053.1); 96.2% to Australian isolate (GU220722.1); 96.3% to Japanese isolate (AB190527.1); and 92.8% to Murcia-Spanish isolate (AY581691.1). Twenty lettuce plants were mechanically inoculated with leaf tissue taken from the four plants collected in the field and tested positive for LBVaV by RT-PCR; 12 days after inoculation, mosaic symptoms were observed in all inoculated plants and six of them were analyzed individually by RT-PCR obtaining a fragment of the expected size. To our knowledge, this is the first report of LBVaV infecting lettuce in Mexico. Further surveys and monitoring of LBVaV incidence and distribution in the region, vector competence of olpidium species, and impact on the crop quality are in progress. References: (1) P. M. Agenor et al. Plant Viruses 2:35, 2008. (2) R. J. Hayes et al. Plant Dis. 90:233, 2006.

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First Report of Banana bract mosaic virus in ‘Cavendish’ Banana in Ecuador

Plant Disease ◽

10.1094/pdis-12-12-1154-pdn ◽

2013 ◽

Vol 97 (7) ◽

pp. 1003-1003

Author(s):

D. F. Quito-Avila ◽

M. A. Ibarra ◽

R. A. Alvarez ◽

M. F. Ratti ◽

L. Espinoza ◽

...

Keyword(s):

Mosaic Virus ◽

Genetic Relationships ◽

The Philippines ◽

Streak Virus ◽

Rt Pcr ◽

First Report ◽

Agricultural Income ◽

Cavendish Banana ◽

Pcr Products ◽

Banana Bract Mosaic Virus

Banana bract mosaic virus (BBrMV), a member of the genus Potyvirus, family Potyviridae, is the causal agent of bract mosaic disease. The disorder has been considered a serious constraint to banana and plantain production in India and the Philippines, where the virus was first identified (3). To date, the presence of BBrMV has been reported only in a few banana-growing countries in Asia (3). In the Americas, BBrMV has been detected by ELISA tests in Colombia only (1). The efficient spread of BBrMV through aphids and vegetative material increases the quarantine risk and requires strict measures to prevent entrance of the virus to new areas. In Ecuador—the world's number one banana exporter—the banana industry represents the main agricultural income source. Thus, early detection of banana pathogens is a priority. In June of 2012, mosaic symptoms in bracts and bunch distortion of ‘Cavendish’ banana were observed in a commercial field in the province of Guayas, Ecuador. Leaves from 35 symptomatic plants were tested for Cucumber mosaic virus (CMV), Banana streak virus (BSV), and BBrMV using double antibody sandwich ELISA kits from Adgen (Scotland, UK). Twenty-one plants tested positive for BBrMV but not for CMV or BSV. In order to confirm the ELISA results, fresh or lyophilized leaf extracts were used for immunocapture reverse transcription (IC-RT)-PCR. In addition, total RNA was extracted from the ELISA-positive samples and subjected to RT-PCR. The RT reactions were done using both random and oligo dT primers. Several sets of primers, flanking conserved regions of the virus coat protein (CP), have been used for PCR-detection of BBrMV (2,3,4). The Ecuadorian BBrMV isolate was successfully detected by three primer sets with reported amplification products of 324, 280, and 260 nucleotides long, respectively (3,4). Amplification products of the expected size were purified and sequenced. All the nucleotide sequences obtained from 20 PCR-positive symptomatic plants were 100% identical between each other. However, 99% identity was observed when PCR products from the Ecuadorian isolate were compared with the corresponding fragment of a BBrMV isolate from the Philippines (NCBI Accession No. DQ851496.1). PCR products of the Ecuadorian isolate, amplified by the different CP primers described above, were assembled into a 408-bp fragment and deposited in the NCBI GenBank (KC247746). Further testing confirmed the presence of BBrMV in symptomatic plants from four different provinces. To our knowledge, this is the first report of BBrMV in Ecuador and the first BBrMV partial nucleotide sequence reported from the Americas. It is worth mentioning that primer set Bract 1/Bract 2, which amplifies a 604-bp product (2), was not effective in detecting the Ecuadorian isolate. It is hypothesized that nucleotide variation at the reverse primer site is the cause of the lack of amplification with this primer set, since the forward primer is part of the sequenced product and no variation was found. Sequencing of the entire CP region is underway to conduct phylogenetic analysis and determine genetic relationships across several other BBrMV isolates. References: (1) J. J. Alarcon et al. Agron 14:65, 2006. (2) M. F. Bateson and J. L. Dale. Arch. Virol 140:515, 1995. (3) E. M. Dassanayake. Ann. Sri Lanka Dept. Agric. 3:19, 2001. (4) M. L. Iskra-Caruana et al. J. Virol. Methods 153:223, 2008.

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First Report of Alfalfa mosaic virus Infecting Tedera (Bituminaria bituminosa (L.) C.H. Stirton var. albomarginata and crassiuscula) in Australia

Plant Disease ◽

10.1094/pdis-04-12-0378-pdn ◽

2012 ◽

Vol 96 (9) ◽

pp. 1384-1384 ◽

Cited By ~ 5

Author(s):

R. A. C. Jones ◽

D. Real ◽

S. J. Vincent ◽

B. E. Gajda ◽

B. A. Coutts

Keyword(s):

Mosaic Virus ◽

Alfalfa Mosaic Virus ◽

Plant Viruses ◽

Yellow Mosaic Virus ◽

Rt Pcr ◽

First Report ◽

Pasture Legumes ◽

Bituminaria Bituminosa ◽

Pcr Products ◽

Burr Medic

Tedera (Bituminaria bituminosa (L.) C.H. Stirton vars albomarginata and crassiuscula) is being established as a perennial pasture legume in southwest Australia because of its drought tolerance and ability to persist well during the dry summer and autumn period. Calico (bright yellow mosaic) leaf symptoms occurred on occasional tedera plants growing in genetic evaluation plots containing spaced plants at Newdegate in 2007 and Buntine in 2010. Alfalfa mosaic virus (AlMV) infection was suspected as it often causes calico in infected plants (1,2) and infects perennial pasture legumes in local pastures (1,3). Because AlMV frequently infects Medicago sativa (alfalfa) in Australia and its seed stocks are commonly infected (1,3), M. sativa buffer rows were likely sources for spread by aphids to healthy tedera plants. When leaf samples from plants with typical calico symptoms from Newdegate (2007) and Buntine (2010) were tested by ELISA using poyclonal antisera to AlMV, Bean yellow mosaic virus (BYMV) and Cucumber mosaic virus (CMV), only AlMV was detected. When leaf samples from 864 asymptomatic spaced plants belonging to 34 tedera accessions growing at Newdegate and Mount Barker in 2010 were tested by ELISA, no AlMV, BYMV, or CMV were detected, despite presence of M. sativa buffer rows. A culture of AlMV isolate EW was maintained by serial planting of infected seed of M. polymorpha L. (burr medic) and selecting seed-infected seedlings (1,3). Ten plants each of 61 accessions from the local tedera breeding program were grown at 20°C in an insect-proof air conditioned glasshouse. They were inoculated by rubbing leaves with infective sap containing AlMV-EW or healthy sap (five plants each) using Celite abrasive. Inoculations were always done two to three times to the same plants. When both inoculated and tip leaf samples from each plant were tested by ELISA, AlMV was detected in 52 of 305 AlMV-inoculated plants belonging to 36 of 61 accessions. Inoculated leaves developed local necrotic or chlorotic spots or blotches, or symptomless infection. Systemic invasion was detected in 20 plants from 12 accessions. Koch's postulates were fulfilled in 12 plants from nine accessions (1 to 2 of 5 plants each), obvious calico symptoms developing in uninoculated leaves, and AlMV being detected in symptomatic samples by ELISA, inoculation of sap to diagnostic indicator hosts (2) and RT-PCR with AlMV CP gene primers. Direct RT-PCR products were sequenced and lodged in GenBank. When complete nucleotide CP sequences (666 nt) of two isolates from symptomatic tedera samples and two from alfalfa (Aq-JX112758, Hu-JX112759) were compared with that of AlMV-EW, those from tedera and EW were identical (JX112757) but had 99.1 to 99.2% identities to the alfalfa isolates. JX112757 had 99.4% identity with Italian tomato isolate Y09110. Systemically infected tedera foliage sometimes also developed vein clearing, mosaic, necrotic spotting, leaf deformation, leaf downcurling, or chlorosis. Later-formed leaves sometimes recovered, but plant growth was often stunted. No infection was detected in the 305 plants inoculated with healthy sap. To our knowledge, this is the first report of AlMV infecting tedera in Australia or elsewhere. References: (1) B. A. Coutts and R. A. C. Jones. Ann. Appl. Biol. 140:37, 2002. (2) E. M. J. Jaspars and L. Bos. Association of Applied Biologists, Descriptions of Plant Viruses No. 229, 1980. (3) R. A. C. Jones. Aust. J. Agric. Res. 55:757, 2004.

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First Report of Cucumber mosaic virus in Taro Plants in China

Plant Disease ◽

10.1094/pdis-09-13-0916-pdn ◽

2014 ◽

Vol 98 (4) ◽

pp. 574-574 ◽

Cited By ~ 6

Author(s):

Y. F. Wang ◽

G. P. Wang ◽

L. P. Wang ◽

N. Hong

Keyword(s):

Cucumber Mosaic Virus ◽

Mosaic Virus ◽

Central China ◽

Post Inoculation ◽

Rt Pcr ◽

Cmv Infection ◽

First Report ◽

Cp Gene ◽

Two Samples ◽

Pcr Products

Taro (Colocasia esculenta L. Schott) is an important crop worldwide. In China, the growing area and productivity of taro increased greatly in recent years. During the 2010 to 2013 growing seasons (from May to July), the incidence of Cucumber mosaic virus (CMV) in taro was determined. Leaf samples from 91 taro plants, including 26 plants of cv. Hongyayu grown in Jiangxi Province in eastern China, 33 plants of cv. Eyu no.1 grown in Hubei Province in central China, and 32 plants of cv. Baiyu grown in Guangxi Province in southwest China were collected randomly and tested for the presence of CMV by reverse transcription (RT)-PCR. Some sampled plants of cv. Hongyayu and Eyu no.1 showed leaf chlorosis or chlorotic spots, and most of the plants of these three cultivars showed feather-like mosaic symptom on their leaves, which was confirmed to be associated with the infection of Dasheen mosaic virus (DsMV) in our previous studies (3). Total RNA was extracted from leaves using CTAB protocol reported by Li et al. (1). Primer set forward 5′-ATGGACAAATCTGAATCAACC-3′/reverse 5′-TAAGCTGGATGGACAACCCGT-3′ (4) was used for the amplification of a 777-bp fragment, which contains the complete capsid protein (CP) gene of 657 bp. PCR products of the expected size were identified from 11 taro samples, including two samples of Hongyayu, three Eyu no.1, and six Baiyu plants. The result did not show any specific association between the symptoms observed and CMV infection. The obtained PCR products were cloned individually into the vector pMD18-T (TaKaRa, Dalian, China). Three independent clones derived from each product were sequenced by Genscript Corp., Nanjing, China. Pairwise comparison of CP gene sequences (Accession No. of one representation CP sequence: KF564789) showed 99.7 to 99.8% nucleotide (nt) and 99.1 to 99.5% deduced amino acid (aa) sequence identity among themselves, and 92.0 to 94.3% and 76.5 to 77.7% nt identities with corresponding sequences of CMV isolates in subgroup I and subgroup II (2), respectively. The maximum likelihood phylogenetic trees of nt and aa sequences generated by Clustal X v1.8 revealed that all these CMV isolates from taro in China fell into subgroup I. To further confirm the CMV infection, leaf saps of CMV infected taro plants of cv. Eyu no.1 were mechanically inoculated onto Pinellia ternate and Cucumis sativus. Plants of P. ternate showed local chlorotic lesions on the inoculated leaves and downward curl of newly grown leaves, and C. sativus showed local chlorotic lesions on the inoculated leaves and crinkle of newly grown leaves at 10 to 15 days post inoculation. The RT-PCR detection confirmed the CMV infection in those inoculated plants, and that the plants of P. ternate were also positive to DsMV, further complementing the results obtained above. To our knowledge, this is the first report of CMV occurrence in taro plants grown in China. Our results indicated that taro plants were widely infected by CMV isolates in subgroup I. This study provides important information for further evaluating the viral sanitary status of taro germplasm and improving the certification program of taro propagation materials in China. References: (1) R. Li et al. J. Virol. Methods 154:48, 2008. (2) P. Palukaitis et al. Adv. Virus. Res. 62:241, 2003. (3) S. M. Shi et al. Acta Hortic. Sin. 39:509, 2012. (4) P. D. Xu et al. Chinese J. Virol. 15:164, 1999.

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First Report of Celery mosaic virus Infecting Celery in Venezuela

Plant Disease ◽

10.1094/pd-90-1111a ◽

2006 ◽

Vol 90 (8) ◽

pp. 1111-1111 ◽

Cited By ~ 2

Author(s):

T. Fernández ◽

O. Carballo ◽

K. Zambrano ◽

M. Romano ◽

E. Marys

Keyword(s):

Mosaic Virus ◽

Microscopic Analysis ◽

Apium Graveolens ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

Leaf Extracts ◽

Electron Microscopic ◽

First Report ◽

Three Samples ◽

Topo Vector

Celery mosaic virus (CeMV) is a significant pathogen of celery (Apium graveolens) worldwide (1). In 2005, in a produce market located in Los Salias, Miranda, celery plants with mottling and leaf malformation were noticed. Electron microscopic analysis of leaf-dip preparations from three symptomatic samples revealed flexuous viral particles that were 750 nm long. Infected cells contained pinwheel inclusions typical of those associated with potyvirus infection. Inoculation of healthy celery plants with leaf extracts from four symptomatic plants produced symptoms identical to those first observed. A survey of five produce markets in Miranda was conducted to determine the prevalence of virus infection in celery using serological and molecular analyses. Mottling and malformation of celery leaflets were observed in all the markets visited. Symptoms were noted in all five markets in each of three visits during a 3-month period. A total of 125 postharvested symptomatic plants were collected from five markets on March 29, 2005 and tested for CeMV using double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) with antiserum provided by F. Rabenstein, BAX, Aschersleben, Germany. Of the 125 samples collected during the survey, 53% were ELISA positive. Twenty ELISA-positive samples were also tested using reverse transcription-polymerase chain reaction (RT-PCR) with general primers for the family Potyviridae (2). All 20 samples produced an amplicon of the expected size (1.7 kbp) after RT-PCR. Amplicons from three samples were cloned into the pCR-TOPO vector (Invitrogen, Carlsbad, CA). Sequence analysis of one clone revealed more than 98% nt to a CeMV isolate from Australia (GenBank Accession No AF203532). To our knowledge, this is the first report of CeMV in Venezuela. Our results suggest that the disease may be widely spread on celery crops growing in the areas surrounding produce markets in Miranda State. References: (1) A. Brunt et al. Viruses of Plants. CAB International, Wallingford, Oxon, UK. 1996. (2) J. Chen et al. Arch. Virol. 146:757, 2001.

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