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

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.

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First report of Coleus blumei viroid 1 in commercial Coleus blumei in the United States

Plant Disease ◽

10.1094/pdis-05-21-0917-pdn ◽

2021 ◽

Author(s):

Gardenia Orellana ◽

Alexander V Karasev

Keyword(s):

United States ◽

Leaf Tissue ◽

The United States ◽

Universal Primers ◽

Rt Pcr ◽

Universal Primer ◽

Tissue Samples ◽

First Report ◽

Specific Pcr ◽

Coleus Blumei

Coleus scutellarioides (syn. Coleus blumei) is a widely grown evergreen ornamental plant valued for its highly decorative variegated leaves. Six viroids, named Coleus blumei viroid 1 to 6 (CbVd-1 to -6) have been identified in coleus plants in many countries of the world (Nie and Singh 2017), including Canada (Smith et al. 2018). However there have been no reports of Coleus blumei viroids occurring in the U.S.A. (Nie and Singh 2017). In April 2021, leaf tissue samples from 27 cultivars of C. blumei, one plant of each, were submitted to the University of Idaho laboratory from a commercial nursery located in Oregon to screen for the presence of viroids. The sampled plants were selected randomly and no symptoms were apparent in any of the samples. Total nucleic acids were extracted from each sample (Dellaporta et al. 1983) and used in reverse-transcription (RT)-PCR tests (Jiang et al. 2011) for the CbVd-1 and CbVd-5 with the universal primer pair CbVds-P1/P2, which amplifies the complete genome of all members in the genus Coleviroid (Jiang et al. 2011), and two additional primer pairs, CbVd1-F1/R1 and CbVd5-F1/R1, specific for CbVd-1 and CbVd-5, respectively (Smith et al. 2018). Five C. blumei plants (cvs Fire Mountain, Lovebird, Smokey Rose, Marrakesh, and Nutmeg) were positive for a coleviroid based on the observation of the single 250-nt band in the RT-PCR test with CbVds-P1/P2 primers. Two of these CbVd-1 positive plants (cvs Lovebird and Nutmeg) were also positive for CbVd-1 based on the presence of a single 150-nt band in the RT-PCR assay with CbVd1-F1/R1 primers. One plant (cv Jigsaw) was positive for CbVd-1, i.e. showing the 150-nt band in RT-PCR with CbVd1-F1/R1 primers, but did not show the ca. 250-bp band in RT-PCR with primers CbVds-P1/P2. None of the tested plants were positive for CbVd-5, either with the specific, or universal primers. All coleviroid- and CbVd-1-specific PCR products were sequenced directly using the Sanger methodology, and revealed whole genomes for five isolates of CbVd-1 from Oregon, U.S.A. The genomes of the five CbVd-1 isolates displayed 96.9-100% identity among each other and 96.0-100% identity to the CbVd-1 sequences available in GenBank. Because the sequences from cvs Lovebird, Marrakesh, and Nutmeg, were found 100% identical, one sequence was deposited in GenBank (MZ326145). Two other sequences, from cvs Fire Mountain and Smokey Rose, were deposited in the GenBank under accession numbers MZ326144 and MZ326146, respectively. To the best of our knowledge, this is the first report of CbVd-1 in the United States.

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Alternanthera mosaic virus Found in Scutellaria, Crossandra, and Portulaca spp. in Florida

Plant Disease ◽

10.1094/pd-90-0833c ◽

2006 ◽

Vol 90 (6) ◽

pp. 833-833 ◽

Cited By ~ 11

Author(s):

C. A. Baker ◽

L. Breman ◽

L. Jones

Keyword(s):

Electron Microscopy ◽

United States ◽

Mosaic Virus ◽

Plant Species ◽

The United States ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

Indicator Plants ◽

Partial Identity ◽

Pcr Products

In the fall of 1998, the Division of Plant Industry (DPI) received vegetative propagations of Scutellaria longifolia (skullcap) with symptoms of foliar mosaic, chlorotic/necrotic ringspots, and wavy line patterns from a nursery in Manatee County. Flexuous particles approximately 500 nm long were found with electron microscopy. The plants tested positive for Papaya mosaic virus (PaMV) in an enzyme-linked immunosorbent assay (ELISA) test with antiserum to PaMV (Agdia, Elkhart, IN). However, in immunodiffusion tests (antiserum from D. Purcifull, University of Florida), this virus gave a reaction of partial identity indicating it was related but not identical to PaMV (1). The original infected plants were kept in a greenhouse. In January 2005, a specimen of Crossandra infundibuliformis (firecracker plant) with mosaic symptoms was submitted to the DPI from a nursery in Alachua County. Inclusions found with light microscopy and particles found with electron microscopy indicated that this plant was infected with a potexvirus. This was confirmed by reverse transcription-polymerase chain reaction (RT-PCR) with primers designed to detect members of the virus family Potexviridae (3). These plants reacted positive to PaMV antiserum in ELISA and gave a reaction of partial identity to PaMV in immunodiffusion. A specimen of Portulaca grandiflora (moss rose) with distorted leaves found at a local retail store was also tested and gave the same results. Leaves from each of the three plant species were rubbed onto a set of indicator plants using Carborundum and potassium phosphate buffer. Total RNA was extracted from symptomatic indicator plants of Nicotiana benthamiana. RT-PCR (3) was performed, and PCR products were sequenced directly. Sequences of approximately 700 bp were obtained for all three plant species and showed 98% identity with each other. BLAST search results showed that these sequences were 93% identical to an Alternanthera mosaic virus (AltMV) sequence at the nucleotide level but only 76% identical to PaMV. The amino acid sequences were 98 and 82% identical to AltMV and PaMV, respectively. The PCR products of the virus from Scutellaria sp. were cloned, resequenced, and the sequence was entered into the GenBank (Accession No. DQ393785). The bioassay results matched those found for AltMV in Australia (2) and the northeastern United States (4), except that the Florida viruses infected Datura stramonium and Digitalis purpurea (foxglove). The virus associated with the symptoms of these three plants appears to be AltMV and not PaMV. AltMV has been found in ornamental plants in Australia, Italy, and the United States (Pennsylvania, Maryland, and now Florida). Since this virus is known to infect several plants asymptomatically and can be easily confused with PaMV serologically, it is likely that the distribution of this virus is much wider than is known at this time. References: (1) L. L. Breman. Plant Pathology Circular No. 396. Fla. Dept. Agric. Consum. Serv. DPI, 1999. (2) A. D. W. Geering and J. E. Thomas. Arch Virol 144:577, 1999. (3) A. Gibbs et al. J Virol Methods 74:67, 1998. (4) J. Hammond et al. Arch Virol. 151:477, 2006.

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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.

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First Report of Alternanthera mosaic virus Infection in Angelonia in the United States

Plant Disease ◽

10.1094/pdis-92-10-1473b ◽

2008 ◽

Vol 92 (10) ◽

pp. 1473-1473 ◽

Cited By ~ 7

Author(s):

B. E. Lockhart ◽

M. L. Daughtrey

Keyword(s):

United States ◽

Nucleotide Sequence ◽

Mosaic Virus ◽

Genomic Sequence ◽

Nutrient Deficiency ◽

Leaf Tissue ◽

The United States ◽

Nucleotide Sequence Analysis ◽

Degenerate Primers ◽

First Report

Stunting, chlorosis, and light yellow mottling resembling symptoms of nutrient deficiency were observed in angelonia (Angelonia angustifolia) in commercial production in New York. Numerous, filamentous particles 520 to 540 nm long and spherical virus particles 30 nm in diameter were observed by transmission electron microscopy (TEM) in negatively stained partially purified extracts of symptomatic Angelonia leaf tissue. Two viruses, the filamentous potexvirus Alternanthera mosaic virus (AltMV) and the spherical carmovirus Angelonia flower break virus (AnFBV) were subsequently identified on the basis of nucleotide sequence analysis of amplicons generated by reverse transcription (RT)-PCR using total RNA isolated from infected leaf tissue. A 584-bp portion of the replicase-encoding region of the AltMV genome was obtained with the degenerate primers Potex 2RC (5′-AGC ATR GNN SCR TCY TG-3′) and Potex 5 (5′-CAY CAR CAR GCM AAR GAT GA-3′) (3). Forward (AnFBV CP 1F-5′-AGC CTG GCA ATC TGC GTA CTG ATA-3′) and reverse (AnFBV CP 1R-5′-AAT ACC GCC CTC CTG TTT GGA AGT-3′) primers based on the published AnFBV genomic sequence (GenBank Accession No. NC_007733) were used to amplify a portion of the viral coat protein (CP) gene. The nucleotide sequence of the amplicon generated using the potexvirus-specific primers (GenBank Accession No. EU679362) was 99% identical to the published AltMV (GenBank Accession No. NC_007731) sequence and the nucleotide sequence of the amplicon obtained using the AnFBV CP primers was 99% identical to the published AnFBV genomic sequence (GenBank Accession No. EU679363). AnFBV occurs widely in angelonia (1) and AltMV has been identified in phlox (2). These data confirm the presence of AltMV and AnFBV in diseased angelonia plants showing stunting and nutrient deficiency-like symptoms and substantiates, to our knowledge, this first report of AltMV in angelonia in the United States. References: (1) S. Adkins et al. Phytopathology 96:460, 2006. (2) J. Hammond et al. Arch. Virol. 151:477, 2006. (3) R. A. A. van der Vlugt and M. Berendeson. Eur. J. Plant Pathol. 108:367, 2002.

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First Report of Alfalfa mosaic virus Associated with Severe Mosaic and Mottling of Pepper (Capsicum annuum) and White Clover (Trifolium repens) in Oklahoma

Plant Disease ◽

10.1094/pdis-07-12-0630-pdn ◽

2012 ◽

Vol 96 (11) ◽

pp. 1705-1705 ◽

Cited By ~ 1

Author(s):

O. A. Abdalla ◽

A. Ali

Keyword(s):

United States ◽

Mosaic Virus ◽

Capsicum Annuum ◽

White Clover ◽

Trifolium Repens ◽

Alfalfa Mosaic Virus ◽

The United States ◽

Morphological Data ◽

Total Rna ◽

First Report

Alfalfa mosaic virus (AMV), a member of the genus Alfamovirus, family Bromoviridae (1), has been reported in 44 states in the United States excluding Oklahoma. During a cucurbit survey in the summer of 2010, severe mosaic and mottling symptoms were observed on many peppers (Capsicum annuum) and white clover (Trifolium repens) plants in Tulsa, Oklahoma. Symptomatic leaf samples from 15 pepper and two white clover plants were collected in the Bixby area and analyzed serologically by dot-immunobinding assay (DIBA) using specific polyclonal antibodies against AMV (Agdia, Inc). Seven out of 15 pepper samples and both white clover samples were tested positive by DIBA to AMV. The remaining symptomatic samples were positive to Cucumber mosaic virus (CMV). Total RNA was extracted from DIBA positive AMV samples by Tri-reagent method. A small aliquot of total RNA was tested by reverse transcription (RT)-PCR using specific primers: AMV-F 5′ GTCCGCGATCTCTTAAAT 3′ and AMV-R 5′ GAAGTTTGGGTCGAGAGA 3′ that were designed to amplify 900 bp of the AMV-RNA 3. Analysis of the PCR products on agarose gel electrophoreses showed that all tested samples showed a band of the expected size while DIBA negative AMV samples did not produce any band. The amplified PCR product (900 bp) obtained from pepper and white clover were cleaned with PCR purification kit (Qiagen, Germantown, MD) and directly sequenced bi-directionally using the above primers. Sequence analysis confirmed that this virus shared 97% identity at nucleotide sequence with RNA 3 of AMV isolate from Madison-USA (GenBank Accession No. K02703). For biological and morphological characterization of the virus, eight pepper plants were mechanically inoculated using 0.1 M K2HPO4 buffer (pH 7.2) with total RNA extracted from AMV positive pepper or white clover plant samples. One to two weeks post-inoculation, all inoculated plants produced severe mosaic, mottling, and stunting. Virus-like particles preparations were obtained from these symptomatic plants according to our previously described method (2) and electron microcopy examination showed typical AMV particles. These biological and morphological data further confirmed the presence of AMV infecting pepper and clover in Oklahoma. AMV is a significant pathogen worldwide and infects more than 600 species in 70 families, especially alfalfa, pepper, soybean, and tobacco (3). AMV has a worldwide distribution, including the United States, and particularly the Midwestern U.S. where the incidence of the virus is on the rise recently because of the presence of its vector (Aphis glycines) (4). To our knowledge, this is the first report of AMV infecting crops in Oklahoma, which could pose a threat to other economic crops grown in Oklahoma, especially soybean. References: (1) E. E. Mueller et al. Plant Dis. 91:266, 2007. (2) A. Ali et al. Plant Dis. 96:243, 2012. (3) J. F. Bol. Mol. Plant Path.4:1, 2003. (4) M. Malapi-Nelson et al. Plant Dis.93:1259, 2009.

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Dicentra, Epimedium, and Heuchera: New Perennial Ornamental Hosts of Tobacco rattle virus in the United States

Plant Disease ◽

10.1094/pdis.2000.84.12.1344a ◽

2000 ◽

Vol 84 (12) ◽

pp. 1344-1344 ◽

Cited By ~ 7

Author(s):

B. E. L. Lockhart

Keyword(s):

Electron Microscopy ◽

United States ◽

Tobacco Rattle Virus ◽

Leaf Tissue ◽

Particle Morphology ◽

The United States ◽

Enzyme Linked Immunosorbent Assay ◽

Infected Leaf ◽

Natural Occurrence ◽

First Report

Yellow ringspotting and concentric line patterns in plants of Dicentra (bleeding heart), Epimedium (barrenwort), and Heuchera (coral bells) from commercial nurseries and home gardens in Minnesota, Michigan, and Massachusetts were associated with infection by Tobacco rattle virus (TRV), which was identified by particle morphology, enzyme-linked immunosorbent assay and immunosorbent electron microscopy. No other viruslike particles were observed by electron microscopy in partially purified preparations of TRV-infected leaf tissue, and TRV was not detected in asymptomatic plants. This is the first report of TRV occurrence in Dicentra in the United States and the first report of TRV occurrence in Epimedium and Heuchera. In previous reports (1,2) we have called attention to the increasing incidence of TRV in vegetatively propagated perennial ornamental plant species in the United States and to the potential for virus spread to crops such as potato, in which TRV has not been reported in the midwestern United States. It is possible that increased international trade in vegetatively propagated ornamental plants may be resulting in the introduction of TRV and other exotic viruses into the United States and elsewhere. It is also possible that the natural occurrence of TRV in North America may be actually more widespread than has been reported. References: (1) B. E. Lockhart et al. Plant Dis. 79:1249, 1995. (2) B. E. Lockhart and J. A. Westendorp. Plant Dis. 82:712, 1998.

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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.

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

Plant Disease ◽

10.1094/pdis-05-13-0500-pdn ◽

2013 ◽

Vol 97 (12) ◽

pp. 1664-1664 ◽

Cited By ~ 3

Author(s):

B. Babu ◽

H. Dankers ◽

S. George ◽

D. Wright ◽

J. Marois ◽

...

Keyword(s):

United States ◽

Mosaic Virus ◽

The United States ◽

Turnip Mosaic Virus ◽

Brassica Carinata ◽

Rt Pcr ◽

First Report ◽

Ethiopian Mustard ◽

Plant Pathol ◽

Pcr Assays

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.

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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 Cucumber mosaic virus Infection in Pachysandra in the United States

Plant Disease ◽

10.1094/pdis-09-14-0974-pdn ◽

2015 ◽

Vol 99 (3) ◽

pp. 422-422 ◽

Cited By ~ 1

Author(s):

S. Bratsch ◽

D. Mollov ◽

B. Lockhart ◽

D. Johnson ◽

S. Ehlenbeck

Keyword(s):

Electron Microscopy ◽

United States ◽

Cucumber Mosaic Virus ◽

Mosaic Virus ◽

Mixed Infection ◽

The United States ◽

Type Ii ◽

Rt Pcr ◽

Cmv Infection ◽

Leaf Deformation

Pachysandra terminalis Siebold & Zucc. (Japanese pachysandra, spurge) is widely used as a groundcover. In early 2012, Japanese pachysandra plants from Missouri, which originated in Pennsylvania, showed symptoms of light and dark green mosaic, leaf deformation, concentric ringspots, and stunting. Initial screening of symptomatic leaf tissue by transmission electron microscopy (TEM) using partially purified extracts confirmed the presence of spherical (~28 nm) and bacilliform (18-nm diameter, 35- to 58-nm length) virus particles. Immunosorbent electron microscopy (ISEM) using antisera to a clover isolate of Alfalfa mosaic virus (AMV) (PVAS 92) and to Cucumber mosaic virus (CMV) (ATCC PVAS-30) obtained from the American Type Culture Collection, Manassas, VA, confirmed the presence of AMV and CMV. No other type of virus-like particles were observed by TEM. After 6 months, nearly 20% of the 4,000 pachysandra cuttings exhibited the described symptoms. However, it is possible that more than 20% of the cuttings were infected with both viruses and not yet exhibiting symptoms. Reverse-transcription PCR (RT-PCR) was done using total RNA extracted with a Qiagen RNeasy kit and Ready-To-Go RT-PCR beads (GE Healthcare, UK Limited, UK). The primer pair CMV-1 (5′-GCCGTAAGCTGGATGGACCA) and CMV-2 (5′-TATGATAAGAAGCTTGTTTTCGCG) were used (3) to obtain a 502-bp amplicon from the coat protein (CP) region of CMV RNA 3. The product was ligated and cloned (pGEM-T Easy Vector System; Promega, USA). Three clones were sequenced (UMGC, USA), and the consensus sequence (Sequencher 5.1, Gene Codes Corp., USA) was deposited in GenBank (Accession No. JX227938). The sequence obtained had 100% identity with a homologous CP CMV sequence (AFQ94058) and 99% identity with several other homologous CP CMV sequences (CAX62443, CCK24369, and 15 others). It also contained an EcoRI site at nucleotides 332 to 337, characteristic of CMV Type II isolates (3). The primer pair AMV1F (5′-ATCCACCGATGCCAGCCTTA) and AMV1R (5′-TTCCGCCTCACTGCTGCTG) generated a 1,047-bp product from AMV RNA1 that was deposited in GenBank (JX227937). This product had 100% identity with a homologous AMV sequence (AFQ94057), and 99% identity with several other homologous AMV sequences (AGV15824, ADO85715, CBX36144). From the data presented here, it was concluded that the pachysandra had a mixed infection of AMV and a Type II isolate of CMV. Occurrence of AMV in pachysandra was first reported in New Jersey in 1982 (2) and reported for the first time in France and Germany in 2000 (1). The presence of CMV infection in pachysandra has not been reported in the present literature. Some of the symptoms associated with AMV infection in pachysandra in New Jersey (2) and Europe (1) were similar to the symptoms produced by pachysandra plants infected with both viruses (ring spots, mosaic, and line patterns). However, some symptoms were unique to the mixed infection in pachysandra by AMV and CMV (leaf deformation, stunting). A potential source of this co-infection could occur when plants are grown near alfalfa fields (AMV infection by aphids) and undergo vegetative propagation (CMV infection by contaminated tools). This is the first report of pachysandra co-infected by AMV and CMV in the United States. References: (1) L. Cardin and B. Moury. Plant Dis. 84:594, 2000. (2) D. E. Hershman and E. H. Varney. Plant Dis. 66:1195, 1982. (3) S. Wylie et al. Aust. J. Agric. Res. 44:41, 1993.

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