scholarly journals 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 ◽  
2012 ◽  
Vol 96 (11) ◽  
pp. 1705-1705 ◽  
Author(s):  
O. A. Abdalla ◽  
A. Ali

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.

Plant Disease ◽  
2013 ◽  
Vol 97 (9) ◽  
pp. 1258-1258 ◽  
Author(s):  
B. Lockhart ◽  
D. Mollov ◽  
M. Daughtrey

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.


2008 ◽  
Vol 9 (1) ◽  
pp. 42 ◽  
Author(s):  
Rayapati A. Naidu ◽  
Gandhi Karthikeyan

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.


Plant Disease ◽  
2008 ◽  
Vol 92 (7) ◽  
pp. 1132-1132 ◽  
Author(s):  
M. C. Cebrián ◽  
M. C. Córdoba-Sellés ◽  
A. Alfaro-Fernández ◽  
J. A. Herrera-Vásquez ◽  
C. Jordá

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.


Plant Disease ◽  
2008 ◽  
Vol 92 (10) ◽  
pp. 1473-1473 ◽  
Author(s):  
B. E. Lockhart ◽  
M. L. Daughtrey

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.


2014 ◽  
Vol 15 (4) ◽  
pp. 151-152 ◽  
Author(s):  
Craig G. Webster ◽  
Erin N. Rosskopf ◽  
Leon Lucas ◽  
H. Charles Mellinger ◽  
Scott Adkins

To the best of our knowledge this is the first report of ToMMV in the United States. Our results provide further characterization of the emerging ToMMV and highlight the continued importance of tobamovirus management in solanaceous crop production. Accepted 9 September 2014. Published 12 October 2014.


Plant Disease ◽  
2010 ◽  
Vol 94 (12) ◽  
pp. 1505-1505 ◽  
Author(s):  
O. L. Fajolu ◽  
R.-H. Wen ◽  
M. R. Hajimorad

Alfalfa mosaic virus (AMV), a member of the genus Alfamovirus in the family Bromoviridae, naturally infects a wide range of plant species (1). Soybean (Glycine max (L.) Merr.) has seldom been reported as a natural host of AMV and there are limited reports of detection of AMV in field-grown soybean plants (4). However, AMV incidence in soybean fields in the midwestern United States has been on the rise in recent years, which is partly attributed to the introduction of the soybean aphid (Aphis glycines) (1,4). In June 2009, soybean plants of cv. Lee68 exhibiting moderate leaf distortion, mottling, and stunting were observed at the East Tennessee Research and Education Center. Leaf samples from 18 symptomatic plants were collected and the sap was extracted and analyzed by antigen-coated indirect ELISA (3) with polyclonal antibodies against AMV, Soybean mosaic virus (SMV), and Bean pod mottle virus (BPMV). None of the samples tested positive for BPMV, but all were found to be infected with SMV. Sap extract from 1 of 18 plants tested positive for AMV and SMV. Sap from this infected plant ground in 10 mM phosphate buffer, pH 7.0, was mechanically inoculated to Carborundum-dusted unifoliate leaves of PI96983, which contains the dominant Rsv1-locus conferring functional immunity to a majority of SMV strains (2). AMV, not SMV, was detected by ELISA in the systemically infected trifoliolate leaves that exhibited moderate mottling, mild leaf distortion, and stunting 14 days postinoculation. Sap was extracted from the infected tissues and the virus was passaged four times through PI96983 before being inoculated to Phaseolus vulgaris cv. Blue Lake. A local lesion isolate was obtained following three successive passages in this host and the isolate was propagated in soybean cv. Williams82. The biologically purified isolate was capable of infecting soybean cvs. L78-379 (Rsv1), L81-4420 (Rsv1), L29 (Rsv3), V94-5152 (Rsv4), Lee68, and Colfax upon sap inoculation. The infected plants exhibited a range of systemic symptoms including mottling, leaf distortion, necrosis, chlorosis, and moderate stunting. To characterize the virus further, total RNA was extracted from infected Williams82 leaf tissues with the RNeasy Plant Mini Kit (Qiagen, Valencia, CA). The RNA served as a template for cDNA synthesis in the presence of random primers. The resultant cDNA served as a template in a PCR assay with primers 1193 (forward) (5′-AGCTGAATTCATGAGTTCTTCACAAC-3′) and 1858 (reverse) (5′-GCTAGCGGCCGCTCAATGACGATC-3′) corresponding to nucleotides 1,193 to 1,210 and 1,858 to 1,840 of RNA3 from AMV-Kr (GenBank Accession No. AB126032), respectively. The amplified fragments were purified and directly sequenced bidirectionally using the same primers. BLAST analysis of the resultant nucleotide sequences showed 98% identity to an AMV isolate from a naturally infected soybean plant in Illinois (GenBank Accession No. HQ185569), and 97% identity to an isolate described from P. vulgaris in the United States (GenBank Accession No. AY340070.1). To our knowledge, this is the first report of natural infection of soybean by AMV in Tennessee. References: (1) J. Bol. Mol. Plant Pathol. 4:1, 2003. (2) M. R. Hajimorad and J. H. Hill. Mol. Plant-Microbe Interact. 14:587, 2001. (3) M. Malapi-Nelson et al. Plant Dis. 93:1259, 2009. (4) E. E. Mueller and C. R. Grau. Plant Dis. 91:266, 2007.


Plant Disease ◽  
2014 ◽  
Vol 98 (8) ◽  
pp. 1163-1163 ◽  
Author(s):  
T. Tian ◽  
K. Posis ◽  
C. J. Maroon-Lango ◽  
V. Mavrodieva ◽  
S. Haymes ◽  
...  

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.


Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1664-1664 ◽  
Author(s):  
B. Babu ◽  
H. Dankers ◽  
S. George ◽  
D. Wright ◽  
J. Marois ◽  
...  

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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