scholarly journals First Report of Clover yellow vein virus in Grain Legumes in Spain

Plant Disease ◽  
2009 ◽  
Vol 93 (1) ◽  
pp. 106-106 ◽  
Author(s):  
V. Ortiz ◽  
S. Castro ◽  
J. Romero

From 1999 to 2002, field surveys were conducted in the legume-growing areas of Spain including Ávila, Badajoz, Cádiz, Córdoba, León, Málaga, Murcia, Salamanca, and Zamora provinces. Leaf tissue from 35 asymptomatic and 224 virus symptomatic plants was sampled and analyzed by indirect-ELISA with a specific monoclonal antibody against the potyvirus group (Adgia, Elkhart, IN). All symptomatic plants of bean (Phaseolus vulgaris L.), broad bean (Vicia faba L.), lentils (Lens culinaris L.), and chickpea (Cicer arietinum L.) were positive for potyvirus infection. Identification as Bean yellow mosaic virus (BYMV) was obtained by double-antibody sandwich (DAS)-ELISA with a polyclonal antiserum (Loewe Biochemica Gmbh, Sauerlach, Germany). To analyze the genetic variability of BYMV Spanish isolates, 33 Spanish isolates were selected at random from our BYMV collection, and extracts from these plants were used with primers 1985 (5′-gagagaatgatacacatactgaa-3′) and 1984 (5′-caaggtgagtggacaatgatgg-3′) to amplify by immunocapture (IC)-reverse transcription (RT)-PCR a 524-nt fragment of the BYMV genome that includes the C-terminal 417 nt of the coat protein and 107 nt from the 3′ untranslated region. The IC-RT-PCR products were cloned into pGEM-T easy vector (Promega, Madison, WI) and a minimum of three clones from each PCR amplification were sequenced. BLAST analysis showed that the sequences of 30 samples were 96 to 98% identical to BYMV, but three samples (GenBank Accession Nos. EU860364–66) from bean, broad bean, and lentils had a high (98%) identity with Clover yellow vein virus (ClYVV). Sequence alignments of the ClYVV Spanish isolates and 14 ClYVV isolates from the GenBank (Accession Nos. AB03308, AB004545, AB011819, AF185959, AF203536, D86044, S77521, D95538–94) were obtained using the Clustal X software. Genetic distances were estimated using the Kimura two-parameter method. Within-population and between-population nucleotide diversities were estimated from the genetic distances (2). ClYVV sequences were phylogenetically separated into two clades: one with the three isolates from Japan (Accession Nos. D89542, D89543, and D89544) and the other with the remaining isolates. Molecular clustering coincides with biology and serological variations of strains 1 and 2 (3). Phylogenetic distances were independent of geographic origin, host, or time of sampling. The nucleotide diversity value among populations (0.18) was higher than within the subpopulations (0.017 and 0.029). dNS/dS in the ClYVV population was 0.031 (<1) and we can conclude that negative selection is occurring in the gene in study and that the population of ClYVV present in Spain is homogenous. In Spain, ClYVV was reported infecting borage (Borago officinalis L.) (1). To our knowledge, this is the first report of natural infection of bean, broad bean, and lentils with ClYVV in Spain. ClYVV might cause important economic losses in grain legumes since it causes an important viral disease of legumes worldwide. References: (1) M. Luis-Arteaga et al. Plant Pathol. 45:38, 1996. (2) M. Nei and T. Gojobori. Mol. Biol. Evol. 3:418, 1986. (3) T. Sasaya et al. Virology 87:1014, 1987.

Plant Disease ◽  
2001 ◽  
Vol 85 (4) ◽  
pp. 444-444 ◽  
Author(s):  
R. Crnov ◽  
R. L. Gilbertson

In 1999, a severe outbreak (i.e., 100% infection) of a virus disease was observed in a single field of common bean in Colusa County, CA. The symptoms included a yellow mosaic, leaf epinasty and, in some plants, a systemic necrosis. This field was adjacent to a clover field that had been harvested early in the development of the bean plants. A preliminary serological test (enzyme-linked immunosorbent assay, ELISA) suggested that the virus infecting these bean plants was Peanut mottle virus (PeMoV). This would represent the first report of this virus in California. A range of common bean cultivars (Black Turtle Soup, Topcrop, California Early Light Red Kidney, and Sutter Pink) were inoculated with sap prepared from symptomatic leaves collected from this field. Symptoms developing on these plants ranged from systemic necrosis (cvs. Sutter Pink and Black Turtle Soup) to strong yellow green mosaic and leaf distortion (cvs. Topcrop and California Early Light Red Kidney). Furthermore, inoculated primary leaves of cv. Topcrop failed to develop local lesions, which is characteristic of PeMoV. ELISAs on all symptomatic plants with antisera against PeMoV, BYMV, BCMV, and BCMNV as well as reverse transcription polymerase chain reaction (RT-PCR) analysis with primer pairs specific for PeMoV, BYMV, BCMV, and BCMNV were negative. To further investigate the nature of this virus, a minipurification method was used to purify virions from symptomatic leaves of all four cultivars. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of purified virions from these cultivars revealed a 32-kDa band consistent with infection by a potyvirus. Transmission electron microscopy analysis of these preparations revealed the presence of potyvirus-like flexous rods (approximately 750 nm long and 10 nm wide). We next designed a primer pair specific for the coat protein gene of Clover yellow vein virus (ClYVV) and RT-PCR with these primers resulted in the amplification of a 630-bp DNA fragment from four isolates of the unknown potyvirus. No fragments were amplified from an uninfected control. The PCR-amplified fragments were direct-sequenced, and sequence comparisons revealed that the sequences of all four isolates were 95% identical to that of ClYVV (Genbank accession number D89541). Subsequently, a ClYVV antiserum was obtained from Simon Scott (Department of Plant Pathology, Clemson University), and ELISAs performed on leaves infected with all four isolates were positive. Finally, to assess whether the virus was seed-transmitted, seed harvested from this field was planted in a greenhouse (two lots of 400 seed each). None of the plants from these seeds developed virus symptoms, suggesting that the virus was not seed-transmitted. Together, these results indicate that the virus disease outbreak in this bean field was caused by ClYVV rather than PeMoV. The inoculum source for the virus was probably the adjacent clover field. This is the first report of ClYVV infecting common bean in California.


Plant Disease ◽  
2010 ◽  
Vol 94 (5) ◽  
pp. 640-640 ◽  
Author(s):  
H.-Y. Liu ◽  
B. Mou ◽  
K. Richardson ◽  
S. T. Koike

In 2009, plants from two spinach (Spinacia oleracea) experimental fields in Monterey County and one commercial spinach field in Ventura County of California exhibited vein-clearing, mottling, interveinal yellowing, and stunting symptoms. For experimental fields, up to 44% of spinach plants have symptoms. With a transmission electron microscope, rigid rod-shaped particles with central canals were observed from plant sap of the symptomatic spinach. Analysis with a double-antibody sandwich-ELISA assay for Beet necrotic yellow vein virus (BNYVV) showed that all 10 symptomatic plants we tested were positive and 5 asymptomatic plants were negative. Symptomatic spinach from both counties was used for mechanical transmission experiments. Chenopodium quinoa, Tetragonia expansa, and Beta vulgaris (sugar beet) showed chlorotic local lesions and B. macrocarpa and spinach showed vein-clearing, mottling, and systemic infections. To further confirm the presence of BNYVV, reverse transcription (RT)-PCR was conducted. Total RNA was extracted from field- and mechanically inoculated symptomatic spinach plants using an RNeasy Plant Kit (Qiagen Inc., Valencia, CA) and used as a template in RT-PCR. Forward and reverse primers specific to the BNYVV RNA-3 P25 protein gene from the beet isolate were used (2). Amplicons of the expected size (approximately 860 bp) were obtained. Four RT-PCR products were sequenced and the sequences were identical (GenBank Accession No. GU135626). Sequences from the spinach plants had 97 to 99% nucleotide and 94 to 100% amino acid identity with BNYVV RNA-3 P25 protein sequences available in the GenBank. On the basis of the data from electron microscopy, indicator plants, serology, and cDNA sequencing, the virus was identified as BNYVV. BNYVV has been reported from spinach fields in Italy (1). To our knowledge, this is the first report of BNYVV occurring naturally on spinach in California. Since BNYVV is transmitted by the zoospores of the soil-inhabiting plasmodiophorid Polymyxa betae, it could be a new threat to spinach production in the state. References: (1) C. R. Autonell et al. Inf. Fitopatol. 45:43, 1995. (2) H.-Y. Liu and R. T. Lewellen, Plant Dis. 91:847, 2007.


Plant Disease ◽  
2011 ◽  
Vol 95 (11) ◽  
pp. 1484-1484 ◽  
Author(s):  
W.-L. Rao ◽  
F. Li ◽  
R.-J. Zuo ◽  
R. Li

Many viruses infect Prunus spp. and cause diseases on them. During a survey of stone fruit trees in 2008 and 2009, flowering cherry (Prunus serrulata) and sweet cherry (P. avium) trees with foliar chlorosis and reddening, stem deformity, and tree stunting were observed in private orchards in Anning and Fumin counties of Yunnan Province. Some sweet cherry trees with severe symptoms yielded small and few fruits and had to be removed. Leaf samples were collected from 68 flowering cherry and 30 sweet cherry trees, either symptomatic or asymptomatic, from private orchards and community gardens in Kunming and counties Anning, Chenggong, Fumin, Jinning, Ludian and Yiliang. Total nucleic acids were extracted with a CTAB extraction method and tested by reverse transcription (RT)-PCR assay using virus-specific primers. Little cherry virus 2 (LChV-2), Cherry virus A (CVA), Prunus necrotic ringspot virus (PNRSV), and Prune dwarf virus (PDV) were detected and infection rates were 68.4, 16.3, 9.2, and 7.1%, respectively. Infection of LChV-2 was common in all counties except Ludian where the orchards were healthy. Of 68 infected trees, 29 were found to be infected with LChV-2 and CVA, PDV or PNRSV. LChV-2 was detected in this study by RT-PCR using a pair of novel primers, LCV2-1 (5′-TTCAATATGAGCAGTGTTCCTAAC-3′) and LCV2-4 (5′-ACTCGTCTTGTGACATACCAGTC-3′), in 59 flowering cherry (87%) and 8 sweet cherry (27%) trees, respectively. The primer pair was designed according to alignment of three available LChV-2 sequences (GenBank Nos. NC_005065, AF416335, and AF333237) to amplify the partial RNA-dependent RNA polymerase gene (ORF1b) of 781 bp. The amplicons of selected samples (Anning26 and Yiliang60) were sequenced directly and sequences of 651 bp (GenBank No. HQ412772) were obtained from both samples. Pairwise comparisons and phylogenetic analysis of the sequences show that the two isolates are identical to one another and share 92 to 96% at the amino acid (aa) sequence level to those of other isolates available in the GenBank database. The sequence data confirm that these isolates are a strain of LChV-2 and genetic variation among different strains is relatively high (2). Biological and serological assays are not available for the LChV-2 detection; therefore, the LChV-2 infections of these trees were further confirmed by RT-PCR using primer pair LCV2-5 (5′-TGTTTGTGTCATGTTGTCGGAGAAG-3′) and LCV2-6 (5′-TGAATACCCGAGAACAAGGACTC-3′), which amplified the helicase domain (ORF1a) of ~451 bp. The amplicons from samples Anning26 and Yiliang60 were cloned and sequenced. The 408-bp sequences (excluding primer sequences) were 92 to 98% identical at the aa sequence level to those of other isolates, confirming again their viral origin. LChV-2 (genus Ampelovirus, family Closteroviridae) (4) has been associated with little cherry disease (LChD), a widespread viral disease of sweet and sour cherries (1,3). The virus is transferred between geographic areas mainly by propagated materials. Ornamental and sweet cherries are important crops in China and LChD has the potential to cause significant economic losses. Thus, certified clean stock should be used to establish new orchards. To our knowledge, this is the first report of LChV-2 in cherries in China. References: (1) N. B. Bajet et al. Plant Dis. 92:234, 2008. (2) W. Jelkmann et al. Acta Hortic. 781:321, 2008. (3) B. Komorowska and M. Cieslińska, Plant Dis. 92:1366, 2008. (4) M. E. Rott and W. Jelkmann. Arch. Virol. 150:107, 2005.


Plant Disease ◽  
2005 ◽  
Vol 89 (5) ◽  
pp. 530-530 ◽  
Author(s):  
Y.-M. Liao ◽  
X.-J. Gan ◽  
B. Chen ◽  
J.-H. Cai

Luohanguo, Siraitia grosvenorii (Swingle) C. Jeffrey, is a perennial cucurbitaceous plant that is an economically important medicinal and sweetener crop in Guangxi province, China. Surveys conducted during the summer to fall seasons of 2003-2004 in northern Guangxi showed symptoms typical of a viral disease, including leaf mottling, mosaic, vein clearing, curling, and shoestring-like distortion in the field. Mechanical inoculation of sap from leaves of symptomatic plants collected from the surveyed areas caused similar symptoms on tissue culture-derived healthy Luohanguo plants. Two sequences of 0.7 and 1.6 kb with 88 and 97% identity to Papaya ringspot virus (PRSV) and Zucchini yellow mosaic virus (ZYMV) were amplified using reverse transcription-polymerase chain reaction (RT-PCR) with purified flexuous viral particles or total RNA extracted from the symptomatic Luohanguo leaves as templates with conserved degenerate potyvirus primers (1). To confirm the results, primers specific for PRSV (PP1/PP2, genome coordinates 4064-4083/5087-5069, GenBank Accession No X97251) and ZYMV (ZP1/ZP2, genome coordinates 5540-5557/7937-7920, GenBank Accession No L31350) were used to perform RT-PCR from the same RNA templates. The expected 1.0- and 2.3-kb fragments were amplified and they were 90 and 95% identical to PRSV and ZYMV in sequence, respectively. Watermelon mosaic virus was not detected. To our knowledge, this is the first report of the occurrence of PRSV and ZYMV in Luohanguo. Reference: (1) A. Gibbs et al. J. Virol. Methods 63:9, 1997.


Plant Disease ◽  
2014 ◽  
Vol 98 (7) ◽  
pp. 1016-1016 ◽  
Author(s):  
B. Babu ◽  
H. Dankers ◽  
M. L. Paret

Scotch bonnet (Capsicum chinense) is a tropical hot pepper variety that is grown in South America, the Caribbean Islands, and in Florida, and is an important cash crop. In Florida, scotch bonnet is grown on ~100 acres annually. Virus-like leaf symptoms including mosaic and yellow mottling were observed on scotch bonnet plants in a field at Quincy, FL, with a disease incidence of ~5%. Two symptomatic and one non-symptomatic plant sample were collected from this field for identification of the causal agent associated with the symptoms. Viral inclusion assays (2) of the epidermal tissues of the symptomatic scotch bonnet samples using Azure A stain indicated the presence of spherical aggregates of crystalline inclusion bodies. Testing of the symptomatic samples using lateral flow immunoassays (Immunostrips, Agdia, Elkhart, IN) specific to Cucumber mosaic virus (CMV), Potato virus Y (PVY), Pepper mild mottle virus (PMMoV), Tobacco mosaic virus (TMV), Zucchini yellow mosaic virus (ZYMV), and Papaya ringspot virus (PRSV), showed a positive reaction only to CMV. The sap from an infected leaf sample ground in 0.01 M Sorensons phosphate buffer (pH 7.0) was used to mechanically inoculate one healthy scotch bonnet plant (tested negative for CMV with Immunostrip) at the 2- to 3-leaf stage. The inoculated plant developed mild mosaic and mottling symptoms 12 to 14 days post inoculation. The presence of CMV in the mechanically inoculated plant was further verified using CMV Immunostrips. Total RNA was extracted (RNeasy Plant Mini Kit, Qiagen, Valencia, CA) from the previously collected two symptomatic and one non-symptomatic scotch bonnet samples. The samples were subjected to reverse-transcription (RT)-PCR assays using SuperScript III One-Step RT-PCR System (Invitrogen, Life Technologies, Grand Island, NY), and using multiplex RT-PCR primer sets (1). The primers were designed to differentiate the CMV subgroup I and II, targeting the partial coat protein gene and the 3′UTR. The RT-PCR assays using the multiplex primers produced an amplicon of 590 bp, with the CMV subgroup I primers. The RT-PCR product was only amplified from the symptomatic leaf samples. The obtained amplicons were gel eluted, and directly sequenced bi-directionally (GenBank Accession Nos. KF805389 and KF805390). BLAST analysis of these sequences showed 97 to 98% nucleotide identities with the CMV isolates in the NCBI database. The isolates collected in Florida exhibited highest identity (98%) with the CMV isolate from tomato (DQ302718). These results revealed the association of CMV subgroup I with symptomatic scotch bonnet leaf samples. Although CMV has been reported from scotch bonnet, this is the first report of its occurrence in Florida. References: (1) S. Chen et al. Acta Biochim Biophys Sin. 43:465, 2011. (2) R. G. Christie and J. R. Edwardson. Plant Dis. 70:273, 1986.


Plant Disease ◽  
2021 ◽  
Author(s):  
Aaron Simkovich ◽  
Susanne Kohalmi ◽  
Aiming Wang

The Niagara fruit belt is one of the richest fruit-producing areas in Canada, contributing to 90% of Ontario's tender fruits such as peach, plum and sweet cherry. Little cherry virus 1 (LCV1) of the genus Velarivirus is a causal agent of little cherry disease which has devastated cherry crops in many regions (Eastwell and Bernardy 1998, Jelkmann and Eastwell, 2011). From 2013 to 2018, foliar symptoms indicative of viral infection such as leaf deformation, ringspot, mottling, vein clearing, and reddening were found on sweet cherry trees grown in the Niagara region. To determine if these trees were infected by a virus, small RNAs (sRNAs) were isolated from separately pooled asymptomatic and symptomatic leaves using the mirPremier microRNA isolation kit (Sigma Aldrich Canada, Oakville, ON). The sRNAs were used to create two libraries (four leaves per library) with the TruSeq Small RNA Sample Prep Kit (Illumina, San Diego, CA). The sRNA libraries were separately sequenced with the MiSeq Desktop Sequencer (Illumina, San Diego, CA). In total, 5,380,196 reads were obtained and Trimmomatic (Bolger et al. 2014) was used to remove adaptors. The remaining 4,733,804 clean reads were assembled into contigs using Velvet 0.7.31 (Zerbino and Birney, 2008) and Oases 0.2.09 (Schulz et al. 2012) with minimum length of 75 nt (Supplementary Table 1). A BLASTn search (Altschul et al. 1997) of the contigs identified the presence of Cherry virus A (genus: Capillovirus), two members of the Ilarvirus genus (Prunus necrotic ringspot virus and Prune dwarf virus) in both libraries. LCV1 was only found in contigs derived from the symptomatic library. Of the clean reads, 22,016 were assembled into six contigs (with lengths ranging from 86 to 116 nt, Supplementary Table 1) mapping to LCV1, covering 7.07% of the viral genome. To confirm LCV1 infection, primers were designed from the assembled contigs and used for reverse transcription polymerase chain reaction (RT-PCR). Amplicons were sequenced and the terminal sequences were determined using 5’ and 3’ RACE Systems (Invitrogen, Burlington, ON). Degenerate primers were designed from multiple sequence alignments of published LCV1 genomes for amplification and primer walking to obtain the sequence of LCV1 (Table S2). The complete genome sequence of LCV1 has a length of 16,934 nt and was deposited in GenBank (accession no. MN508820). A BLASTn search showed that this isolate is nearly identical (99.6% sequence identity) to an isolate from California (accession no. MN131067). To determine the incidence of infection, a field survey was performed at the same location during spring months of 2014 to 2018 using RT-PCR with primers specific to the viral coat protein gene (Supplementary Tale 2). Among 46 cherry trees sampled, two (4.3%) trees were infected with LCV1 and showed negative results with CVA, PNRSV and PDV. Both trees displayed mild suturing of primary and secondary veins (Supplementary Figure 1). LCV1 has been identified in Western stone fruit producing regions (British Columbia in Canada, and Washington, California, and Oregon in the United States of America). To the best of our knowledge, this is the first report of LCV1 in any eastern region of Canada. The low incidence of LCV1 suggests that this virus is not widespread in this region. Routine monitoring and detection of LCV1 is required to prevent this devastating cherry disease from spreading in this region.


Plant Disease ◽  
2015 ◽  
Vol 99 (3) ◽  
pp. 423-423 ◽  
Author(s):  
J. A. M. Rezende ◽  
V. M. Camelo ◽  
D. Flôres ◽  
A. P. O. A. Mello ◽  
E. W. Kitajima ◽  
...  

Beet necrotic yellow vein virus (BNYVV) is an economically important pathogen of sugar beet (Beta vulgaris var. saccharifera) in several European, and Asian countries and in the United States (3). The virus is transmitted by the soil-inhabiting plasmodiophorid Polymyxa betae and causes the rhizomania disease of sugar beet. In November 2012, plants of B. vulgaris subsp. vulgaris cv. Boro (red table beet) exhibiting mainly severe characteristic root symptom of rhizomania were found in a commercial field located in the municipality of São José do Rio Pardo, State of São Paulo, Brazil. No characteristic virus-inducing foliar symptom was observed on diseased plants. The incidence of diseased plants was around 70% in the two visited crops. As the hairy root symptom is indicative of infection by BNYVV, the present study aimed to detect and identify this virus associated with the diseased plants. Preliminary leaf dip analysis by transmission electron microscopy revealed the presence of very few benyvirus-like particles. Total RNA was extracted from roots of three symptomatic plants and one asymptomatic plant according to Toth et al. (3). One-step reverse-transcription–polymerase chain reaction (RT-PCR) was performed as described by Morris et al. (2) with primers that amplify part of the coat protein gene at RNA2. The initial assumption that the hairy root symptom was associated with BNYVV infection was confirmed by the amplification of a fragment of ~500 bp from all three symptomatic samples. No amplicon was obtained from the asymptomatic control plant. Amplicons were directly sequenced, and the consensus nucleotide and deduced amino acid sequences showed 100% identity. The nucleotide sequence for one amplicon (Accession No. KM433683) was compared with other sequences deposited in GenBank. The nucleotide (468 nt) and deduced amino acid (156 aa) sequences shared 93 to 100 and 97 to 99% identity, respectively with the corresponding nucleotide and amino acid sequences for other isolates of type A of BNYVV. The virus was transmitted to three of 10 red table beet plants inoculated with contaminated soil, and infection was confirmed by nested RT-PCR, as described by Morris et al. (1), and nucleotide sequencing. This is the first report on the occurrence of BNYVV in Brazil, which certainly will affect the yield of red table beet in the producing region. Therefore, mapping of the occurrence of BNYVV in red table beet-producing areas in Brazil for containment of the spread of the virus is urgent. In the meantime, precautions should be taken to control the movement of contaminated soil and beet roots, carrots, or any vegetable grown on infested land that might introduce the virus to still virus-free regions. References: (1) J. Morris et al. J. Virol. Methods 95:163, 2001. (2) D. D. Sutic et al. Handbook of Plant Virus Diseases. CRC Press, Boca Raton, Florida, 1999. (3) I. K. Toth et al. Methods for the Detection and Quantification of Erwinia carotovora subsp. atroseptica (Pectobacterium carotovorum subsb. atrosepticum) on Potatoes: A Laboratory Manual. Scottish Crop Research Institute, Dundee, Scotland, 2002.


Plant Disease ◽  
2008 ◽  
Vol 92 (10) ◽  
pp. 1469-1469 ◽  
Author(s):  
T. Tornos ◽  
M. C. Cebrián ◽  
M. C. Córdoba-Sellés ◽  
A. Alfaro-Fernández ◽  
J. A. Herrera-Vásquez ◽  
...  

During the spring of 2007, pea plants (Pisum sativum L.) (cvs. Utrillo and Floreta) showing virus-like symptoms were observed in several commercial fields in the southern and eastern regions of Catalonia, Spain. Incidence of symptomatic plants ranged from 5 to 15% and was distributed in both small and large patches. Infected plants exhibited yellow mosaic leaf symptoms that later became translucent. Leaves gradually curled and in some cases developed enations near the veins on the abaxial surface. Plants were “bushy” and had shortened internodes. Infection prior to pod formation resulted in pods that were distorted and stunted (1). The infected leaves and pods were tested by indirect-ELISA with a potyvirus-specific antibody (Agdia, Elkhart, IN) and double-antibody sandwich (DAS)-ELISA with antibodies specific to Pea enation mosaic virus (PEMV), Broad bean wilt virus 1 (BBWV-1), Beet western yellow virus (BWYV), Bean yellow mosaic virus (BYMV), Alfalfa mosaic virus (AMV), and Tomato spotted wilt virus (TSWV) (Loewe Biochemica GmbH, Sauerlach, Germany). PEMV was detected in all 24 symptomatic samples that were collected from 10 locations between March 2007 and March 2008. Thirteen of these samples also tested positive for BWYV, but no differences in symptom expression were observed in plants infected with both viruses or PEMV alone. PEMV was also identified in seven broad bean plants (Vicia faba L.) from three additional locations. These plants expressed interveinal yellow mosaic on leaves and deformed pods. The genomic sequence of PEMV-1 (GenBank Accession No. L04573) was used to design primers to amplify a 451-nt segment of the polymerase gene by reverse transcription (RT)-PCR; PEMV-D (5′-TGACCATGAGTCCACTGAGG-3′), PEMV-R (5′-AGTATCTTCCAACAACCACAT-3′). One ELISA-positive sample was analyzed and the expected size amplicon was generated. Direct sequencing (GenBank Accession No. EU652339) revealed that PEMV-1 and our pea isolate have nucleotide sequence identities of 95%. To our knowledge, this is the first report of PEMV in Spain, which might cause important economical losses since PEMV is an important viral disease of pea and other legumes worldwide. Reference: (1) J. S. Skaf and G. A. Zoeten. No. 372 (No. 257 revised) in: Description of Plant Viruses. AAB, Kew, Surrey, England, 2000.


Plant Disease ◽  
2014 ◽  
Vol 98 (5) ◽  
pp. 702-702 ◽  
Author(s):  
I. Malandraki ◽  
N. Vassilakos ◽  
C. Xanthis ◽  
G. Kontosfiris ◽  
N. I. Katis ◽  
...  

In the summer of 2012, zucchini (Cucurbita pepo L.) plants of F1 hybrid Rigas showing very severe malformation and blisters in leaves and fruit were observed in the prefectures of Ilia and Messinia, Peloponnese, southwestern Greece. Over 100 samples were collected and only a few were found by double antibody sandwich (DAS)-ELISA to be singly or mixed infected with the commonly encountered Cucumber mosaic virus (CMV, genus Cucumovirus), Zucchini yellow mosaic virus (ZYMV, genus Potyvirus), and Watermelon mosaic virus (WMV, genus Potyvirus), to which Rigas is known to be tolerant. All affected plants were also tested by DAS-ELISA and RT-PCR (2) for the presence of Moroccan watermelon mosaic virus (MWMV; genus Potyvirus), a virus not previously reported in Greece, and were consistently found positive by both methods. Sap from plants in which MWMV was solely detected was used to mechanically inoculate Chenopodium quinoa Willd. and cucurbit species (zucchini, cucumber, melon, and watermelon). C. quinoa produced chlorotic local lesions, while cucurbits showed very severe mosaic and malformation of leaves. Zucchini plants of F1 hybrids Rigas, Golden (tolerant to WMV and ZYMV), and Elion (not exhibiting any tolerance) grown in a screenhouse produced equivalent severe symptoms on leaves and fruits. Furthermore, transmission experiments in a non-persistent manner using a clone of Myzus persicae Sulz. and zucchini plants of F1 hybrid Boreas as donor and test plants were carried out. Ten plants were used in each experiment (one aphid/plant) and this was repeated five times (50 plants in total). The transmission rate was high ranging from 75 to 90%. RT-PCR obtained amplicons of 627 bp were subjected to direct sequencing (GenBank Accession No KF772944), which revealed 99% sequence identity to the corresponding region of a MWMV Tunisian isolate (EF579955). In 2013, in addition to zucchini plants found MWMV positive, watermelon (Citrullus lanatus Thunb.) plants from the same region of Peloponnese showing leaf malformation and mosaic symptoms were found MWMV positive (4/30) by DAS-ELISA and RT-PCR, revealing the virus establishment and further spread. In the Mediterranean basin, the virus has already been reported in Morocco, Italy, France, Spain, Tunisia, and Algeria, where it has emerged recently from a common source, has quickly become established through rapid dissemination and is considered as an important emerging threat (4). Isolates from these countries, including the present one from Greece, are very closely molecularly related to each other, contrary to isolates from sub-Saharan Africa (South Africa, Sudan, Congo, Zimbabwe, Niger, Cameroon, Nigeria) that are much more divergent (1,3). To our knowledge, this is the first report of MWMV in Greece. References: (1) H. Lecoq et al. Plant Dis. 85:547, 2001. (2) H. Lecoq et al. New Dis. Rep. 16:19, 2007. (3) A. T. Owolabi et al. Int. J. Virol. 8:258, 2012. (4) S. Yakoubi et al. Arch. Virol. 153:775, 2008.


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