First Report of Turnip mosaic virus Infecting Brassica carinata (Ethiopian Mustard) in the United States

Brassica carinata L. Braun (Ethiopian mustard) is an annual oil seed crop currently being evaluated for its potential use as a source of biofuel. Due to its high content of erucic acid, it provides a biodegradable non-fossil fuel feedstock that has many applications ranging from biofuels to other industrial uses such as polymers, waxes, and surfactants. Moreover, high glucosinolate content adds the scope of B. carinata being used as a bio-fumigant. B. carinata is amenable to low input agriculture and has great economic potential to be used as a winter crop, especially in the southeastern United States. Virus-like leaf symptoms including mosaic, ringspot, mottling, and puckering were observed on B. carinata (cvs. 080814 EM and 080880 EM) in field trials at Quincy, FL, during spring 2013, with disease incidence of >80%. A more extensive survey of the same field location indicated that mosaic symptoms were the most common. Viral inclusion assays (1) of leaves with a range of symptoms indicated the presence of potyvirus-like inclusion bodies. Total RNA extracts (RNeasy Plant Mini Kit, Qiagen Inc., Valencia, CA) from six symptomatic samples and one non-symptomatic B. carinata sample were subjected to reverse transcription (RT)-PCR assays using SuperScript III One-Step RT-PCR System (Invitrogen, Life Technologies, NY), and two sets of potyvirus-specific degenerate primers MJ1-F and MJ2-R (2) and NIb2F and NIb3R (3), targeting the core region of the CP and NIb, respectively. The RT-PCR assays using the CP and NIb specific primers produced amplicons of 327 bp and 350 bp, respectively, only in the symptomatic leaf samples. The obtained amplicons were gel-eluted and sequenced directly (GenBank Accession Nos. KC899803 to KC899808 for CP and KC899809 to KC899813 for NIb). BLAST analysis of these sequences revealed that they came from Turnip mosaic virus (TuMV). Pairwise comparisons of the CP (327 bp) and NIb (350 bp) segments revealed 98 to 99% and 96 to 98% nucleotide identities, respectively, with corresponding sequences of TuMV isolates. These results revealed the association of TuMV with symptomatic B. carinata leaf samples. Although TuMV has been reported from B. carinata in Zambia (4), this is the first report of its occurrence on B. carinata in the United States. Considering the importance of B. carinata as a biofuel source, this report underscores the need for developing effective virus management strategies for the crop. References: (1) R. G. Christie and J. R. Edwardson. Plant Dis. 70:273, 1986. (2) M. Grisoni et al. Plant Pathol. 55:523, 2006. (3) L. Zheng et al. Plant Pathol. 59:211, 2009. (4) D. S. Mingochi and A. Jensen. Acta Hortic. 218:289, 1988.

Download Full-text

First Report of Alfalfa mosaic virus in Viburnum lucidum in Spain

Plant Disease ◽

10.1094/pdis-92-7-1132b ◽

2008 ◽

Vol 92 (7) ◽

pp. 1132-1132 ◽

Cited By ~ 2

Author(s):

M. C. Cebrián ◽

M. C. Córdoba-Sellés ◽

A. Alfaro-Fernández ◽

J. A. Herrera-Vásquez ◽

C. Jordá

Keyword(s):

Mosaic Virus ◽

Natural Infection ◽

Alfalfa Mosaic Virus ◽

The United States ◽

Rt Pcr ◽

Water Control ◽

First Report ◽

Pcr Product ◽

Pcr Assays ◽

The Mediterranean

Viburnum sp. is an ornamental shrub widely used in private and public gardens. It is common in natural wooded areas in the Mediterranean Region. The genus includes more than 150 species distributed widely in climatically mild and subtropical regions of Asia, Europe, North Africa, and the Americas. In January 2007, yellow leaf spotting in young plants of Viburnun lucidum was observed in two ornamental nurseries in the Mediterranean area of Spain. Symptoms appeared sporadically depending on environmental conditions but normally in cooler conditions. Leaf tissue from 24 asymptomatic and five symptomatic plants was sampled and analyzed by double-antibody sandwich (DAS)-ELISA with specific polyclonal antibodies against Tomato spotted wilt virus (TSWV) (Loewe Biochemica, Sauerlach, Germany) and Alfalfa mosaic virus (AMV) (SEDIAG S.A.S, Longvic, France). All symptomatic plants of V. lucidum were positive for Alfalfa mosaic virus (AMV). The presence of AMV was tested in the 29 samples by one-step reverse transcription (RT)-PCR with the platinum Taq kit (Invitrogen Life Technologies, Barcelona, Spain) using primers derived from a partial fragment of the coat protein gene of AMV (2). The RT-PCR assays produced an expected amplicon of 700 bp in the five symptomatic seropositive samples. No amplification product was observed when healthy plants or a water control were used as a template in the RT-PCR assays. One PCR product was purified (High Pure PCR Product Purification Kit; Roche Diagnostics, Mannheim, Germany) and directly sequenced (GenBank Accession No. EF427449). BLAST analysis showed 96% nucleotide sequence identity to an AMV isolate described from Phlox paniculata in the United States (GenBank Accession No. DQ124429). This virosis has been described as affecting Viburnum tinus L. in France (1). To our knowledge, this is the first report of natural infection of Viburnum lucidum with AMV in Spain, which might have important epidemiological consequences since V. lucidum is a vegetatively propagated ornamental plant. References: (1) L. Cardin et al. Plant Dis. 90:1115, 2006. (2) Ll. Martínez-Priego et al. Plant Dis. 88:908, 2004.

Download Full-text

First Report of Cucumber green mottle mosaic virus on Melon in the United States

Plant Disease ◽

10.1094/pdis-02-14-0176-pdn ◽

2014 ◽

Vol 98 (8) ◽

pp. 1163-1163 ◽

Cited By ~ 35

Author(s):

T. Tian ◽

K. Posis ◽

C. J. Maroon-Lango ◽

V. Mavrodieva ◽

S. Haymes ◽

...

Keyword(s):

United States ◽

Mosaic Virus ◽

Seed Production ◽

Citrullus Lanatus ◽

The United States ◽

Rt Pcr ◽

First Report ◽

Rigid Rod ◽

Yolo County ◽

Das Elisa

In July 2013, a melon (Cucumis melo var. Saski) field in Yolo County, California, was inspected as part of a phytosanitary inspection for seed production. The leaves of the plants showed mosaic, green mottle, and blotches. When plant sap was examined using a transmission electron microscope, rigid rod-shaped particles were observed. Melon plant samples were analyzed by both CDFA and USDA APHIS PPQ laboratories and tested positive using DAS-ELISA against Cucumber green mottle mosaic virus (CGMMV) (Agdia, Elkhart, IN). To confirm the presence of CGMMV, total RNA was analyzed by RT-PCR using primers CGMMV-F5370 5′-CTAATTATTCTGTCGTGGCTGCGGATGC-3′ and CGMMV-R6390 5′-CTTGCAGAATTACTGCCCATA-3′ designed by PPQ based on 21 genomic sequences of CGMMV found worldwide. The 976-bp amplicon was sequenced (GenBank Accession No. KJ453559) and BLAST analysis showed the sequence was 95% identical to MP and CP region of CGMMV isolates reported from Russia (GQ495274, FJ848666), Spain (GQ411361), and Israel (KF155231), and 92% to the isolates from China (KC852074), Korea (AF417243), India (DQ767631), and Japan (D12505). These analyses confirm the virus was CGMMV. To our knowledge, this is the first report of CGMMV in the United States. Based on our sequence data, a second set of primers (CGMMV-F5796 5′-TTGCGTTTAGTGCTTCTTATGT-3′ and CGMMV-R6237 5′-GAGGTGGTAGCCTCTGACCAGA-3′), which amplified a 440-bp amplicon from CGMMV CP region, was designed and used for testing all the subsequent field and seed samples. Thirty-seven out of 40 randomly collected Saski melon samples tested positive for CGMMV, suggesting the virus was widespread in the field. All the melon samples also tested positive for Squash mosaic virus (SqMV) using DAS-ELISA (Agdia). Therefore, the symptoms observed likely resulted from a mixed infection. The melon field affected by CGMMV was immediately adjacent to fields of cucumber (Cucumis sativus var. Marketmore 76) and watermelon (Citrullus lanatus var. Sugar Baby) crops, both for seed production with no barrier between the crops. CGMMV was also detected from symptomatic plants from both fields. Seed lots used for planting all three crops were tested and only the melon seed was positive for CGMMV, suggesting the seed as the source of infection. The sequenced 440-bp RT-PCR amplicons from CGMMV-infected cucumber and watermelon plants and melon seeds were 99% identical to the CGMMV from the field melon. A cucumber plant infected with CGMMV but not SqMV was used for mechanical inoculation at the Contained Research Facility at University of California, Davis. Inoculated cucumber, melon, and watermelon plants showed green mottle and mosaic similar to that observed in the field. CGMMV is a highly contagious virus and damage by this virus on cucurbit crops has been reported in regions where CGMMV is present (2). CGMMV was detected on cucumber grown in greenhouses in Canada with 10 to 15% yield losses reported due to this virus (1). The three cucurbit crops in Yolo County were planted in an isolated area with no other cucurbits nearby. Measures, including destroying all the cucurbit plant material, have been taken to eradicate the virus. Use of CGMMV free cucurbit seed is necessary for prevention of this disease. References: (1) K.-S. Ling et al. Plant Dis. 98:701, 2014. (2) J. Y. Yoon et al. J. Phytopathol. 156:408, 2008.

Download Full-text

First Report of Natural Infection of Greenhouse Tomatoes by Potato spindle tuber viroid in the United States

Plant Disease ◽

10.1094/pdis-07-10-0516 ◽

2010 ◽

Vol 94 (11) ◽

pp. 1376-1376 ◽

Cited By ~ 9

Author(s):

K.-S. Ling ◽

D. Sfetcu

Keyword(s):

United States ◽

Potato Spindle Tuber Viroid ◽

The United States ◽

Mechanical Transmission ◽

Rt Pcr ◽

Tomato Plants ◽

First Report ◽

Viroid Infection ◽

Plant Pathol ◽

Greenhouse Tomatoes

In April 2009, a large number of tomato plants (Solanum lycopersicum L.) grown in a commercial greenhouse facility near Los Angles, CA exhibited general plant stunting (short internodes) and foliar symptoms that included distortion, chlorosis, and scattered necrotic spotting. Over time, the leaves began to exhibit a purple color and curling. Diseased plants were often elongated and frail with spindly shoots. The disease resulted in a significant yield loss due to reduced fruit size. Disease symptoms described above are generally different from those of Pepino mosaic virus (PepMV) infection, which causes yellow mosaic or patches on leaves and marbling of fruits. The disease was initially localized in certain areas in a greenhouse despite using a number of cultural management efforts including vigorous scouting, roguing of diseased plants, and strict hygiene and cleaning practices. The disease was also observed in neighboring greenhouses by the spring of 2010. A standard panel of tests for common tomato viruses and viroids were conducted using the appropriate serological or PCR assays. Reverse transcription (RT) PCR analysis of nine symptomatic plants with pospiviroid-specific primers, Pospil-RE and Pospil-FW (3), produced an amplicon of the expected size (~196 bp) while three healthy looking tomato plants did not. Subsequently, full viroid genomic sequences were obtained through RT-PCR with primer sets specific for Potato spindle tuber viroid (PSTVd), 3H1/2H1 (2), as well as for the pospiviroid genus, MTTVd-F and MTTVd-R (1). Sequences obtained from direct sequencing of amplicons or cloned PCR products from one isolate were identical and consisted of a full viroid genome of 358 nt, which was named PSTVd-CA1 (GenBank Accession No. HM753555). BLASTn queries of the NCBI database showed that this isolate had a high sequence identity (98%) to other PSTVd isolates (i.e., EF044304, X52037, and Y09577). The disease was reproducible upon mechanical transmission (1) on three tomato ‘Moneymaker’ plants, which expressed symptoms that were similar to those on the source plants. Recovery of PSTVd on the inoculated tomato plants was confirmed by RT-PCR and sequencing. Because of its susceptibility to viroid infection, tomato ‘Moneymaker’ plants are commonly used as indicators for the study of pospiviroids, including PSTVd. Natural PSTVd infection on greenhouse tomatoes has been reported in Europe (3) and New Zealand. Although a number of reports in the United States have been published on naturally occurring PSTVd infections of potatoes, to our knowledge, this is the first report of a natural PSTVd infection on tomatoes in the United States. The exact source of the PSTVd inoculum in the current disease outbreak is unknown, but it could have been introduced from infected potato or ornamental plants (4) or through infected tomato seeds. The disease epidemic might have been enhanced by frequent hands-on activities in greenhouse tomato production and the environmental conditions (high temperature and intense lighting) in the greenhouse that favor symptom expression. References: (1) K.-S. Ling and W. Zhang, Plant Dis. 93:1216, 2009. (2). A. M. Shamloul et al. Can. J. Plant Pathol. 19:89, 1997. (3) J. Th. J. Verhoeven et al. Eur. J. Plant Pathol. 110:823, 2004. (4) J. Th. J. Verhoeven et al. Plant Pathol. 59:3, 2010.

Download Full-text

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.

Download Full-text

First Report of Alfalfa mosaic virus Occurrence in Hydrangea in the United States

Plant Disease ◽

10.1094/pdis-07-12-0618-pdn ◽

2013 ◽

Vol 97 (9) ◽

pp. 1258-1258 ◽

Cited By ~ 4

Author(s):

B. Lockhart ◽

D. Mollov ◽

M. Daughtrey

Keyword(s):

Electron Microscopy ◽

United States ◽

Mosaic Virus ◽

Alfalfa Mosaic Virus ◽

Leaf Tissue ◽

The United States ◽

Spherical Particles ◽

Genomic Sequences ◽

Rt Pcr ◽

First Report

In spring of 2012, a previously unrecorded virus-like disease characterized by conspicuous yellow leaf blotching (calico symptoms) was observed in plants of Hydrangea macrophylla in a single location in Southampton, NY. Bacilliform and spherical particles resembling those of Alfalfa mosaic virus (AMV) were observed by transmission electron microscopy (TEM) in partially purified extracts from symptomatic leaf tissue. The identity of the virus was confirmed by immunosorbent electron microscopy (ISEM) (4) using antiserum to AMV (ATCC PVAS 92) that both trapped and decorated the virions. Three primer pairs designed from available AMV RNA 1, RNA 2, and RNA 3 genomic sequences were used to generate amplicons from the hydrangea AMV isolate. Reverse-transcription (RT)-PCR was done using total RNA extracted from symptomatic hydrangea leaf tissue with a Qiagen RNeasy kit, and Ready-to-Go RT-PCR beads (GE Healthcare). Amplicons of 1,049, 1,013, and 658 bp were obtained using the primer pairs AMV1F (5′-ATCCACCGATGCCAGCCTTA)/AMV1R (5′-TTCCGCCTCACTGCTGTCTG), AMV2F (5′-GATCGCCGGAAGTGATCCAG)/AMV2R (5′-TCACCGGAAGCAACAACGAA), and AMV3F (5′-GCCGGTTCTCCAAAGGGTCT)/AMV3R (5′-CGCGTCGAAGTCCAGACAGA), respectively. The PCR products were cloned using a TOPO TA cloning kit (Invitrogen) and three clones of each were sequenced. The sequences obtained from the hydrangea AMV RNA 1 (JX154090), RNA 2 (JX154091), and RNA 3 (JX154092) had 95 to 98% nucleotide sequence identity to homologous genomic sequences of known AMV isolates. To our knowledge, this is the first report of AMV occurrence in H. macrophylla in the United States. This virus has been reported to occur in H. macrophylla in British Columbia (3), but in a previous survey its presence was not detected in hydrangeas in the United States (1). A report of possible AMV infection in H. macrophylla in Italy (2) was based solely on symptomatology and cross-protection tests and therefore cannot be verified. The AMV-infected hydrangea plants were found by ISEM to also contain low concentrations of Hydrangea ringspot virus (HRSV) and Hydrangea chlorotic mottle virus (HdCMV). However, based on previous evidence of single and mixed infections (3), it is unlikely that the calico symptoms observed were influenced by the presence of HRSV and HdCMV. This report is of interest both because AMV, unlike HRSV and HdCMV, causes foliar symptoms that would render hydrangea plant unmarketable, and because the disease can be spread by a number of common aphid species that transmit AMV. It will also serve to alert growers and diagnosticians to the potential threat posed by AMV infection. References: (1) T. C. Allen et al. Acta Hortic. 164:85, 1985. (2) G. Belli. Phytopathol. Mediterr. 7:70, 1968. (3) A. W. Chiko and S. E. Godkin. Plant Dis. 70:541, 1986. (4) B. E. L. Lockhart et al. Phytopathology 82:691, 1992.

Download Full-text

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.

Download Full-text

First Report of a New Potyvirus, Tricyrtis virus Y, and Lily virus X, a Potexvirus, in Tricyrtis formosana in the United States

Plant Disease ◽

10.1094/pdis-92-4-0648a ◽

2008 ◽

Vol 92 (4) ◽

pp. 648-648 ◽

Cited By ~ 3

Author(s):

R. L. Jordan ◽

M. A. Guaragna ◽

T. Van Buren ◽

M. L. Putnam

Keyword(s):

United States ◽

Amino Acid ◽

Mosaic Virus ◽

The United States ◽

Cdna Clones ◽

Gene Products ◽

Rt Pcr ◽

Degenerate Primers ◽

Specific Primers ◽

First Report

Tricyrtis formosana (toad lily) is an herbaceous perennial in the family Liliaceae. Native to Asia, T. formosana is now used in the United States as an ornamental border plant in woodland and shade gardens. A T. formosana var. stolonifera plant showing chlorosis and mild mosaic symptoms obtained from a commercial grower in Columbia County, Oregon tested positive for potyvirus by ELISA using our genus Potyvirus broad spectrum reacting PTY-1 Mab (3). Electron microscopic examination of negatively stained leaf-dip preparations from symptomatic leaves showed a mixture of two sizes of flexuous rod-shaped particles, approximately 700 nm long (resembling potyviruses) and 470 nm long (resembling potexviruses). Total RNA extracts from symptomatic leaves were used in reverse transcription (RT)-PCR assays with potyvirus- or potexvirus-specific primers. The degenerate primers for the genus Potyvirus (2) direct the amplification of approximately 1,600-bp fragments from the 3′ terminus of most potyviruses. Overlapping potexvirus cDNA clones were generated using degenerate genus Potexvirus replicase primers, and later, virus-specific primers in 3′ RACE (4). The RT-PCR amplified fragments were cloned and sequenced. Analysis of the 1,688 nt potyvirus sequence (GenBank Accession No. AY864850) using BLAST showed highest identity with members of the Bean common mosaic virus (BCMV) subgroup of potyviruses. Pairwise amino acid comparisons of the CP region of the new potyvirus showed 78% identity to strains of Bean common mosaic necrosis virus, 77% identity with Soybean mosaic virus and Ceratobium mosaic virus, 72 to 76% identity to strains of BCMV, and only 50 to 64% identity with 54 other potyviruses. Additionally, similar pairwise analysis of the CP nucleotide sequence and 3′NCR of the new potyvirus generally revealed the same identity trend as described for the CP amino acid sequences, albeit with the highest nucleotide identities at less than 73% for CP and less than 66% for the 3′NCR. These results suggest that this virus is a new species in the genus Potyvirus (1), which we have tentatively named Tricyrtis virus Y (TrVY). BLAST analysis of the 3′ terminal 3,010 nt potexvirus sequence (GenBank Accession No. AY864849) showed 89% nucleotide identity with Lily virus X (LVX). Pairwise amino acid comparisons of the putative gene products revealed 98, 95, 94 and 99% identity with LVX TGBp1, TGBp2, TGBp3-like, and CP, respectively, and 97% identity with the 108 nt 3′NCR. Homology with other members of the genus Potexvirus was less than 50% for these corresponding genes and gene products. ELISA and RT-PCR analysis for these two viruses in toad lily plants obtained from a grower in Illinois also revealed the presence of TrVY in three of seven cultivars and LVX coinfecting only one of the plants. The standard propagation method for T. formosana is plant division, which along with mechanical contact, provides efficient means for spread of both viruses. To our knowledge, this is the first description of this potyvirus and the first report of any potyvirus in T. formosana. LVX has been reported in Lilium formosanum, but to our knowledge, this is also the first report of LVX in T. formosana. References: (1) P. H. Berger et al. Potyviridae. Page 819 in: Virus Taxonomy: 8th Rep. ICTV, 2005. (2) M. A. Guaragna et al. Acta. Hortic. 722:209, 2006. (3) R. L. Jordan and J. Hammond. J. Gen. Virol. 72:1531, 1991. (4) C. J. Maroon-Lango et al. Arch. Virol. 150:1187, 2005.

Download Full-text

First Report of Wisteria vein mosaic virus in Wisteria sinensis in the United States of America

Plant Health Progress ◽

10.1094/php-2008-0818-01-br ◽

2008 ◽

Vol 9 (1) ◽

pp. 42 ◽

Cited By ~ 1

Author(s):

Rayapati A. Naidu ◽

Gandhi Karthikeyan

Keyword(s):

United States ◽

Mosaic Virus ◽

United States Of America ◽

The United States ◽

Home Gardens ◽

First Report ◽

Woody Perennial ◽

Wisteria Sinensis ◽

First Time ◽

Wisteria Vein Mosaic Virus

The ornamental Chinese wisteria (Wisteria sinensis) is a woody perennial grown for its flowering habit in home gardens and landscape settings. In this brief, the occurrence of Wisteria vein mosaic virus (WVMV) was reported for the first time in Chinese wisteria in the United States of America. Accepted for publication 18 June 2008. Published 18 August 2008.

Download Full-text

First Report of Potato spindle tuber viroid Naturally Infecting Field Tomatoes in the Dominican Republic

Plant Disease ◽

10.1094/pdis-09-13-0992-pdn ◽

2014 ◽

Vol 98 (5) ◽

pp. 701-701

Author(s):

K.-S. Ling ◽

R. Li ◽

D. Groth-Helms ◽

F. M. Assis-Filho

Keyword(s):

United States ◽

Dominican Republic ◽

Mosaic Virus ◽

Potato Spindle Tuber Viroid ◽

The United States ◽

Disease Outbreak ◽

Ringspot Virus ◽

Rt Pcr ◽

Spot Virus ◽

Three Samples

In recent years, viroid disease outbreaks have resulted in serious economic losses to a number of tomato growers in North America (1,2,3). At least three pospiviroids have been identified as the causal agents of tomato disease, including Potato spindle tuber viroid (PSTVd), Tomato chlorotic dwarf viroid (TCDVd), and Mexican papita viroid (MPVd). In the spring of 2013, a severe disease outbreak with virus-like symptoms (chlorosis and plant stunting) was observed in a tomato field located in the Dominican Republic, whose tomato production is generally exported to the United States in the winter months. The transplants were produced in house. The disease has reached an epidemic level with many diseased plants pulled and disposed of accordingly. Three samples collected in May of 2013 were screened by ELISA against 16 common tomato viruses (Alfalfa mosaic virus, Cucumber mosaic virus, Impatiens necrotic spot virus, Pepino mosaic virus, Potato virus X, Potato virus Y, Tobacco etch virus, Tobacco mosaic virus, Tobacco ringspot virus, Tomato aspermy virus, Tomato bushy stunt virus, Tomato mosaic virus, Tomato ringspot virus, Tomato spotted wilt virus, Groundnut ringspot virus, and Tomato chlorotic spot virus), a virus group (Potyvirus group), three bacteria (Clavibacter michiganensis subsp. michiganensis, Pectobacterium atrosepticum, and Xanthomonas spp.), and Phytophthora spp. No positive result was observed, despite the presence of symptoms typical of a viral-like disease. Further analysis by RT-PCR using Agdia's proprietary pospiviroid group-specific primer resulted in positive reactions in all three samples. To determine which species of pospiviroid was present in these tomato samples, full-genomic products of the expected size (~360 bp) were amplified by RT-PCR using specific primers for PSTVd (4) and cloned using TOPO-TA cloning kit (Invitrogen, CA). A total of 8 to 10 clones from each isolate were selected for sequencing. Sequences from each clone were nearly identical and the predominant sequence DR13-01 was deposited in GenBank (Accession No. KF683200). BLASTn searches into the NCBI database demonstrated that isolate DR13-01 shared 97% sequence identity to PSTVd isolates identified in wild Solanum (U51895), cape gooseberry (EU862231), or pepper (AY532803), and 96% identity to the tomato-infecting PSTVd isolate from the United States (JX280944). The relatively lower genome sequence identity (96%) to the tomato-infecting PSTVd isolate in the United States (JX280944) suggests that PSTVd from the Dominican Republic was likely introduced from a different source, although the exact source that resulted in the current disease outbreak remains unknown. It may be the result of an inadvertent introduction of contaminated tomato seed lots or simply from local wild plants. Further investigation is necessary to determine the likely source and route of introduction of PSTVd identified in the current epidemic. Thus, proper control measures could be recommended for disease management. The detection of this viroid disease outbreak in the Dominican Republic represents further geographic expansion of the viroid disease in tomatoes beyond North America. References: (1). K.-S. Ling and M. Bledsoe. Plant Dis. 93:839, 2009. (2) K.-S. Ling and W. Zhang. Plant Dis. 93:1216, 2009. (3) K.-S. Ling et al. Plant Dis. 93:1075, 2009. (4) A. M. Shamloul et al. Can. J. Plant Pathol. 19:89, 1997.

Download Full-text

First Report of Natural Infection of Penstemon acuminatus with Cucumber mosaic virus in the Treasure Valley Region of Idaho and Oregon

Plant Disease ◽

10.1094/pdis-93-7-0762a ◽

2009 ◽

Vol 93 (7) ◽

pp. 762-762 ◽

Cited By ~ 1

Author(s):

R. K. Sampangi ◽

C. Almeyda ◽

K. L. Druffel ◽

S. Krishna Mohan ◽

C. C. Shock ◽

...

Keyword(s):

Cucumber Mosaic Virus ◽

Mosaic Virus ◽

Great Basin ◽

Natural Infection ◽

The United States ◽

Native Plant ◽

Rt Pcr ◽

Cmv Infection ◽

Spot Virus ◽

First Report

Penstemons are perennials that are grown for their attractive flowers in the United States. Penstemon species (P. acuminatus, P. deustus, and P. speciosus) are among the native forbs considered as a high priority for restoration of great basin rangelands. During the summer of 2008, symptoms of red spots and rings were observed on leaves of P. acuminatus (family Scrophulariaceae) in an experimental trial in Malheur County, Oregon where the seeds from several native forbs were multiplied for restoration of range plants in intermountain areas. These plants were cultivated as part of the Great Basin Native Plant Selection and Increase Project. Several native wildflower species are grown for seed production in these experimental plots. Plants showed red foliar ringspots and streaks late in the season. Fungal or bacterial infection was ruled out. Two tospoviruses, Impatiens necrotic spot virus and Tomato spotted wilt virus, and one nepovirus, Tomato ring spot virus, are known to infect penstemon (2,3). Recently, a strain of Turnip vein-clearing virus, referred to as Penstemon ringspot virus, was reported in penstemon from Minnesota (1). Symptomatic leaves from the penstemon plants were negative for these viruses when tested by ELISA or reverse transcription (RT)-PCR. However, samples were found to be positive for Cucumber mosaic virus (CMV) when tested by a commercially available kit (Agdia Inc., Elkhart, IN). To verify CMV infection, total nucleic acid extracts from the symptomatic areas of the leaves were prepared and used in RT-PCR. Primers specific to the RNA-3 of CMV were designed on the basis of CMV sequences available in GenBank. The primer pair consisted of CMV V166: 5′ CCA ACC TTT GTA GGG AGT GA 3′ and CMV C563: 5′ TAC ACG AGG ACG GCG TAC TT 3′. An amplicon of the expected size (400 bp) was obtained and cloned and sequenced. BLAST search of the GenBank for related sequences showed that the sequence obtained from penstemon was highly identical to several CMV sequences, with the highest identity (98%) with that of a sequence from Taiwan (GenBank No. D49496). CMV from infected penstemon was successfully transmitted by mechanical inoculation to cucumber seedlings. Infection of cucumber plants was confirmed by ELISA and RT-PCR. To our knowledge, this is the first report of CMV infection of P. acuminatus. With the ongoing efforts to revegetate the intermountain west with native forbs, there is a need for a comprehensive survey of pests and diseases affecting these plants. References: (1) B. E. Lockhart et al. Plant Dis. 92:725, 2008. (2) D. Louro. Acta Hortic. 431:99, 1996. (3) M. Navalinskiene et al. Trans. Estonian Agric. Univ. 209:140, 2000.

Download Full-text