scholarly journals First Report of Cucurbit yellow stunting disorder virus in Morocco

Plant Disease ◽  
2000 ◽  
Vol 84 (5) ◽  
pp. 596-596 ◽  
Author(s):  
C. Desbiez ◽  
H. Lecoq ◽  
S. Aboulama ◽  
M. Peterschmitt
Keyword(s):  
Important Change ◽  
Enzyme Linked Immunosorbent Assay ◽  
Yellow Leaf ◽  
Vegetable Crops ◽  
Specific Primers ◽  
First Report ◽  
Large Populations ◽  
Healthy Control ◽  
Symptomless Plant ◽  
Beet Pseudo Yellows Virus

In October, 1999, severe yellowing symptoms were observed in a melon (Cucumis melo L.) crop grown under plastic tunnels in the region of Agadir, Morocco. Large populations of whiteflies (Bemisia tabaci) were noticed during the early stages of the crop. At harvest, leaf samples were collected from two symptomatic plants and one symptomless plant. A mature yellow leaf was assayed from each symptomatic plant and for one of these two plants a younger leaf exhibiting only yellow spots. Cucurbit aphid-borne yellows virus, which causes similar symptoms in melons, was not detected by double-antibody sandwich enzyme-linked immunosorbent assay tests. Total RNA was extracted from fresh leaf tissues and submitted to reverse transcription and polymerase chain reaction with primers specific to two whitefly-transmissible viruses: Beet pseudo-yellows virus (BPYV) and Cucurbit yellow stunting disorder virus (CYSDV) (2). No amplification was obtained with BPYV-specific primers. In contrast, an expected 465-bp product was amplified in all samples from symptomatic plants with CYSDV-specific primers. No amplification was detected in samples from the symptomless plant nor from healthy control plants. B. tabaci-transmitted CYSDV has been reported in the Middle East, southwestern Europe, and North America (1,4). This is the first report of CYSDV in Morocco, and it follows the first report of another B. tabaci-transmitted virus, Tomato yellow leaf curl virus, in tomato (3), suggesting an important change in the viral pathosystem affecting vegetable crops in Morocco. References: (1) Kao et al. Plant Dis. 84:101, 2000. (2) Livieratos et al. Plant Pathol. 47:362, 1998. (3) Peterschmitt et al. Plant Dis. 83:1074, 1999. (4) Wisler et al. Plant Dis. 82:270, 1998.

scholarly journals First Report of Cucurbit yellow stunting disorder virus in Commercial Cucumber Greenhouses in France

Plant Disease ◽  
2003 ◽  
Vol 87 (5) ◽  
pp. 600-600 ◽  
Author(s):  
C. Desbiez ◽  
H. Lecoq ◽  
M. Girard ◽  
A. C. Cotillon ◽  
L. Schoen
Keyword(s):  
Trialeurodes Vaporariorum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Specific Primers ◽  
First Report ◽  
Whole Plant ◽  
Leaf Tissues ◽  
Polymerase Chain ◽  
Beet Pseudo Yellows Virus ◽  
French Isolate ◽  
Das Elisa

In autumn 2001, severe yellowing symptoms were observed on greenhouse-grown cucumbers near Perpignan (southern France). Leaf samples were collected from two sites where plants displayed symptoms ranging from limited yellowing of the older leaves to severe, complete yellowing of the whole plant. Cucurbit aphid-borne yellows virus, a polerovirus that causes similar symptoms was not detected in doubleantibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) using a specific antiserum. Total RNA was extracted from fresh leaf tissues and used in reverse transcription-polymerase chain reaction (1) with primers specific for two whitefly-borne viruses also inducing yellows and occurring in the Mediterranean basin (1): Beet pseudo yellows virus (BPYV, genus Closterovirus) transmitted by Trialeurodes vaporariorum (West.) and Cucurbit yellow stunting disorder virus (CYSDV, genus Crinivirus) transmitted by Bemisia tabaci (Genn.). No BPYV was detected in this survey, but CYSDV was present in all samples. In subsequent surveys conducted in the spring and summer of 2002, BPYV and CYSDV were detected, sometimes in mixed infections, in samples collected from the same region. The complete CYSDV coat protein gene was amplified by PCR using specific primers (2), yielding the expected-size fragment of 756 bp. The French isolate (GenBank Accession No. AY204220) shared 99.6 to 100% nucleotide sequence identity in the sequenced CP fragments (700 nt) with isolates of the most common, highly homogenous subgroup of CYSDV that has emerged recently in the Middle East, southwestern Europe (Spain and Portugal), United States, and Morocco (2). To our knowledge, this is the first report of CYSDV in France and it shows the threat represented by the current emergence of B. tabaci-transmitted viruses. References: (1) I. C. Livieratos et al. Plant Pathol. 47:362, 1998. (2) L. Rubio et al. J. Gen. Virol. 82:929, 2001.

scholarly journals First Report of Cucurbit chlorotic yellows virus Infecting Melon in China

Plant Disease ◽  
2011 ◽  
Vol 95 (3) ◽  
pp. 354-354 ◽  
Author(s):  
R. Zeng ◽  
F. M. Dai ◽  
W. J. Chen ◽  
J. P. Lu
Keyword(s):  
Cucumis Melo ◽  
Specific Primers ◽  
Virus Diagnosis ◽  
High Tunnel ◽  
First Report ◽  
Reverse Transcription Pcr ◽  
Yellow Color ◽  
Large Populations ◽  
Pcr Products ◽  
Cucurbit Chlorotic Yellows Virus

In October 2007, symptoms of chlorosis on the upper leaves and a bright yellow color on the lower leaves were observed sporadically on hami melon (Cucumis melo cv. Xuelihong) in a high tunnel in Nanhui of Shanghai, China. Disease progresses from initial mottling of leaves into leaves that are completely yellow with the veins remaining green. The oldest leaves develop symptoms first, so these leaves have a pronounced even yellow color. In October 2009, these symptoms were found in all melons produced in the suburbs of Shanghai. These symptoms were similar to those caused by Cucurbit yellow stunting disorder virus (CYSDV) and Cucurbit chlorotic yellows virus (CCYV) (1–3). Twelve samples from symptomatic melons were collected in the Jiading, Nanhui, Fengxian, and Chongming districts of Shanghai for virus diagnosis. Large populations of whiteflies were observed in association with the diseased cucurbit crops. Total RNA was extracted with Trizol reagents (Invitrogen, Carlsbad, CA). We used random primers (9-mer) for reverse transcription-PCR. Extracts were for CYSDV using specific primers CYSDV-CP-F (5′-ATGGCGAGTTCGAGTGAGAA-3′) and CYSDV-CP-R (5′-TCAATTACCACAGCCACCTG-3′) to amplify a 756-bp fragment of coat protein gene and CCYV using specific primers CCYV-HSP-F1 (5′-TGCGTATGTCAATGGTGTTATG-3′) and CCYV-HSP-R1 (5′-ATCCTTCGCAGTGAAAAACC-3′) to amplify a 462-bp fragment of the HSP gene (1). CYSDV was not found in all samples. The expected 462-bp target fragment of CCYV was obtained in all samples but not from any of the healthy controls. All the 462-bp PCR products were cloned to pGEM-T vector (Promega, Madison, WI) and sequenced. All sequences obtained were homologous. A comparison of the submitted sequence (GenBank Accession No. HQ148667) with those in GenBank showed that the sequence had 100% nucleotide identity to the Hsp70h sequences of (CCYV) isolates from Japan (Accession Nos. AB523789 and AB457591) (1,4), Taiwan (Accession No. HM120250) (2), and mainland of China (Accession Nos. GU721105, GU721108, and GU721110). CCYV is a new member of the genus Crinivirus, first discovered in Japan in 2004 (4) and reported in Taiwan in 2009 (2). To our knowledge, this is the first report of CCYV on melon in China. References: (1) Y. Gyoutoku et al. Jpn. J. Phytopathol. 75:109, 2009. (2) L.-H. Huang et al. Plant Dis. 94:1168, 2010. (3) L. Z. Liu et al. Plant Dis.94:485, 2010. (4) M. Okuda et al. Phytopathology 100:560, 2010.

scholarly journals First Report of Cucurbit aphid-borne yellows virus in Tunisia Causing Yellows on Five Cucurbitacious Species

Plant Disease ◽  
2005 ◽  
Vol 89 (7) ◽  
pp. 776-776 ◽  
Author(s):  
M. Mnari Hattab ◽  
J. Kummert ◽  
S. Roussel ◽  
K. Ezzaier ◽  
A. Zouba ◽  
...  
Keyword(s):  
Citrullus Lanatus ◽  
Aphis Gossypii ◽  
Pcr Amplification ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Fresh Leaf ◽  
First Report ◽  
Reference Isolate ◽  
Leaf Tissues ◽  
Beet Pseudo Yellows Virus

Viruses, distributed worldwide on cucurbits, cause severe damage to crops. Virus surveys in 2003 and 2004 were made in all the major cucurbit-growing areas in Tunisia. Large populations of aphids (Aphis gossypii Glover) and severe yellowing symptoms of older leaves of cucurbits were observed in outdoor and under plastic-tunnel cultivation, suggesting the presence of Cucurbit aphid-borne yellows virus (CABYV, genus Polerovirus, family Luteoviridae). Leaf samples collected from symptomatic and asymptomatic plants of melon (Cucumis melo L.), cucumber (C. sativus L.), squash (Cucurbita pepo L.), watermelon (Citrullus lanatus L.), and ware cucurbit (Ecballium elaterium L. T. Richard) were screened for the presence of CABYV using enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR). Reference isolate, CABYV-N (GenBank Accession No. X76931) was provided by H. Lecoq (INRA-Monfavet Cedex, France). Sample extracts from fresh leaf tissues were tested using ELISA with an antiserum prepared against this isolate. In addition, total RNA was extracted from fresh leaf tissues according to the technique of Celix et al. (2) using the Titan RT-PCR kit from Roche Diagnostics (Penzberg, Germany). Forward primer (5′-GAGGCGAAGGCGAAGAAATC-3′) and reverse primer (5′-TCTGGACCTGGCACTTGATG-3′) were designed with the available sequence of the reference isolate. ELISA tests demonstrated that 91 plants were positive among 160 plants tested with severe yellowing symptoms. All asymptomatic plants were negative. RT-PCR results yielded an expected 550-bp product that was amplified from the reference isolate. Of the 160 plants tested using ELISA, 106 plants were screened with RT-PCR including the 91 plants that were positive in ELISA. These 91 plants also were positive after RT-PCR amplification as were 12 more plants. This demonstrated that the RT-PCR test is more sensitive. No amplicons were produced from extracts of asymptomatic plants, RNA preparations of Cucurbit yellow stunting disorder virus (CYSDV), or Beet pseudo yellows virus (BPYV) positive controls provided by B. Falk (University of California, Davis). CYSDV and BPYV can induce similar yellowing symptoms in cucurbits. The results of the ELISA and RT-PCR tests showed that CABYV is widely distributed on five cucurbit species in the major growing areas of Tunisia including the northern, Sahel, central, and southern regions where it was detected, respectively, in 10 of 25, 11 of 21, 24 of 37, and 58 of 77 samples tested. CABYV was detected at the rates of 63 of 72 on melon, 10 of 21 on cucumber, 17 of 24 on squash, 10 of 25 on watermelon, and 3 of 18 on ware cucurbit. CABYV also seems to be widespread throughout the Mediterranean Basin (1,3,4), but to our knowledge, this is the first report of the occurrence of CABYV in Tunisia on different species of cucurbit and ware cucurbit. References: (1) Y. Abou-Jawdah et al. Crop Prot. 19:217, 2000. (2) A. Celix et al. Phytopathology 86:1370, 1996. (3) M. Juarez et al. Plant Dis. 88:907, 2004. (4) H. Lecoq et al. Plant Pathol. 41:749, 1992.

scholarly journals First Report of Tomato rugose yellow leaf curl virus Infecting Tomato in Argentina

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1662-1662 ◽  
Author(s):  
E. Ben Guerrero ◽  
A. De Francesco ◽  
M. L. García ◽  
P. A. Balatti ◽  
E. Dal Bó
Keyword(s):  
Buenos Aires ◽  
Yellow Leaf ◽  
Specific Primers ◽  
Tomato Plants ◽  
First Report ◽  
Begomovirus Genome ◽  
Sense Strand ◽  
Dna Fragment ◽  
Leaf Curl Virus ◽  
Leaf Curl

Tomato plants exhibiting typical symptoms of begomovirus infection, including leaf deformation, curling, and yellowing, were collected from cultivated fields in Lavalle Department, Corrientes, Argentina, in 2010. Although the number of affected plants was only 2% within a farm, the finding is of considerable importance since the white fly Bemisia tabaci is widely spread within the country, even in other southernmost areas such as the cinturón hortícola de Buenos Aires (horticultural belt around Buenos Aires). DNA isolated from infected tomato leaves collected from three symptomatic tomato plants was amplified by PCR with specific primers designed to amplify a region of component A and B of the Begomovirus genome (3). The amplified DNA fragment was sequenced and a new set of primers were designed based on the obtained sequences. A DNA fragment of about 1,300 bp was amplified and later the complete genome, which was 2,683 bp long. No fragments were obtained when template DNA was from non-infected leaf samples. The 2,683-bp fragment was annotated at the NCBI under Accession No. KC132844. Analysis by NCBI BLAST showed that it was highly homologous to DNA-A component of Begomovirus. Furthermore, the genome organization was typical of DNA-A component of bipartite New World begomovirus. The sequence had one open reading frame (ORF) on the viral-sense strand (AV1/CP) and four ORFs on the complementary-sense strand (AC1/Rep, AC2/TrAp, AC3/REn, and AC4). In order to confirm this finding, the viral genome was amplified by rolling circle amplification (RCA, TempliPhi 100 Amplification Kit, Amersham Biosciences) as described by the manufacturer instructions. The RCA full-length product was digested with XhoI generating a 2,700-bp DNA fragment, suggesting the presence of only one restriction site, in agreement with the bioinformatics analysis of the KC132844 sequence. This PCR product was used as template in PCR reactions with specific primers to DNA-A or DNA-B components. While the DNA-A primers generated the expected 1,300-bp fragment, those homologous to the DNA-B component did not generate amplifications. These results confirmed the identity of the DNA-A component of the isolate MT8. The full sequence of the DNA-A component was 94% homologous to the DNA-A sequence of the Uruguayan begomovirus Tomato Rugose Yellow Leaf Curl Virus-[U4.1] (JN381823.1). Therefore, considering our results and the criteria proposed by Fauquet (1), isolate MT8 is a new species of begomovirus described recently (2). This is the first report of TRYLCV in one of the main areas of tomato production in Argentina. This virus might be accompanying another begomovirus TYVSV that provoked yellow veins symptoms in tomato plants cultivated in the same area of Corrientes. These viruses appeared recently and concomitantly with the introduction of the white fly Bemisia spp. in the area, which is one of the main production areas of tomato and provides fresh tomatoes to the whole country, and in wintertime to the city of Buenos Aires, when the horticultural belt around Buenos Aires is not under production. References: (1) C. M. Fauquet et al. Arch Virol 153:783, 2008. (2) B. Márquez-Martín et al. Arch Virol 157:1137, 2012. (3) M. R. Rojas et al. Plant Dis. 77:340, 1993.

scholarly journals First Report of Cowpea Aphid-Borne Mosaic Potyvirus from Cowpeas Grown Commercially in the U.S.

Plant Disease ◽  
1997 ◽  
Vol 81 (8) ◽  
pp. 959-959 ◽  
Author(s):  
A. S. Kline ◽  
E. J. Anderson
Keyword(s):  
Chenopodium Quinoa ◽  
The United States ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mechanical Transmission ◽  
First Report ◽  
Chlorotic Mottle ◽  
Cowpea Aphid ◽  
Healthy Control ◽  
Systemic Infections ◽  
The U.S

Cowpea aphid-borne mosaic potyvirus (CABMV) is one of several seed-borne viruses known to limit cowpea (Vigna unguiculata (L.) Walp. subsp. unguiculata) production in Africa, Europe, and Asia, but CABMV has not been reported on commercially grown cowpeas in the United States (1). However, a sesame (Sesamum indicum L.)-infecting isolate of CABMV was recently characterized from plants growing near cowpea introduction plots in Georgia (2). In February 1997, we received samples of three seed lots of cowpea cv. Chinese Red that had been harvested in southern Texas during 1996. Approximately 28% of the plants grown from these seed lots expressed strong mosaic symptoms on primary and trifoliate leaves. Viruslike symptoms were reproduced following mechanical transmission to plants of Chinese Red cowpea, Nicotiana benthamiana, and soybean (Glycine max L.) cv. Lee. When Coronet and Pinkeye Purple Hull-BVR cowpeas were inoculated with sap extracts from symptomatic Chinese Red plants, chlorotic lesions developed on inoculated leaves, but only Coronet plants supported symptomless systemic infections. Similarly inoculated plants of Chenopodium quinoa (L.) and common bean (Phaseolus vulgaris L.) cvs. Pinto and Black Valentine developed localized chlorotic lesions. In Ouchterlony gel diffusion assays, extracts from symptomatic cowpea plants did not react with antisera to blackeye cowpea mosaic potyvirus (BlCMV), cucumber mosaic cucu-movirus (CMV), southern bean mosaic sobemovirus, cowpea mosaic comovirus, cowpea severe mosaic comovirus, or cowpea chlorotic mottle bromovirus. In the indirect enzyme-linked immunosorbent assay, sap extracts from symptomatic plants reacted with antiserum to CABMV, giving OD values at A405 of 0.10 to 0.25, and reacted weakly with antiserum to BlCMV, with OD values at A405 less than 0.035. Extracts from healthy control plants gave OD values at A405 less than 0.010. No positive reactions were obtained with antisera to bean yellow mosaic potyvirus, peanut mottle potyvirus, soybean mosaic potyvirus, or CMV. To our knowledge, this is the first report of CABMV in commercially grown cowpea from the U.S. References: (1) A. G. Gillaspie et al. Plant Dis. 79:388, 1995. (2) H. R. Pappu et al. Arch. Virol. 142:1, 1997.

scholarly journals First Report of Virus and Phytoplasma Pathogens Associated with Yellow Leaf Syndrome of Sugarcane in Cuba

Plant Disease ◽  
1999 ◽  
Vol 83 (12) ◽  
pp. 1177-1177 ◽  
Author(s):  
Y. Arocha ◽  
L. Gonzalez ◽  
E. L. Peralta ◽  
P. Jones
Keyword(s):  
Enzyme Linked Immunosorbent Assay ◽  
Local Alignment ◽  
Polymorphism Analysis ◽  
Yellow Leaf ◽  
Nested Polymerase Chain Reaction ◽  
Aster Yellows ◽  
First Report ◽  
Pcr Products ◽  
Search Tool ◽  
Saccharum Sp

Yellow leaf syndrome (YLS) has been seen recently in sugarcane (Saccharum sp.) in Cuba. The primary symptom is a yellow discoloration of the midrib that may spread from the midrib to the lamina in cane 6 months and older. In certain cultivars, such as CP 5243, EPC 17-395, and F31-156, a reddish coloration has been observed. In severe cases, plants are stunted and can be pulled easily. YLS was first reported from Hawaii, followed by Brazil, Florida, and Australia, where it is associated with a luteovirus: sugarcane yellow leaf virus (ScYLV). However, in South Africa, YLS is associated with a phytoplasma: sugarcane yellow leaf phytoplasma (ScYLP) (1). A survey performed in Jovellanos, Matanzas, Cuba, for ScYLV, using enzyme-linked immunosorbent assay with antiserum provided by B. E. L. Lockhart, showed that only a small percentage of canes with YLS carried the virus. A nested polymerase chain reaction (PCR) (1) was used to amplify phytoplasma 16S/23S rDNA from sugarcane leaves with YLS symptoms, also collected from Jovellanos. Restriction fragment length polymorphism analysis with HaeIII, RsaI, and AluI produced patterns similar to those of members of the aster yellows group for 260 of 277 samples tested. Sequencing of the 16S/23S intergenic rDNA PCR products, followed by BLAST (basic local alignment search tool) analysis, confirmed the high homology (97%) of these amplimers to the DNA of phytoplasmas belonging to the aster yellows I-A subgroup. This is the first report of ScYLV and ScYLP from Cuba, and it demonstrates the difficulty of determining the identity of the YLS pathogen based on symptoms alone. Reference: (1) C. P. R. Cronjé et al. Ann. Appl. Biol. 133:177, 1998.

scholarly journals First Report of a Begomovirus Associated with Tomato Yellow Leaf Curl Disease in Ethiopia

Plant Disease ◽  
2006 ◽  
Vol 90 (7) ◽  
pp. 974-974 ◽  
Author(s):  
S. L. Shih ◽  
S. K. Green ◽  
W. S. Tsai ◽  
L. M. Lee ◽  
J. T. Wang ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Tomato Yellow Leaf ◽  
Tomato Mosaic Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Yellow Leaf ◽  
First Report ◽  
Sequence Identity ◽  
Pcr Product ◽  
Leaf Curl Disease ◽  
Leaf Curl

During December 2003, severe leaf yellowing, leaf curling, and stunting symptoms were observed in tomato (Lycopersicon esculentum) plantings in Melkassa (1,550 m above sea level), Ethiopia. Eleven symptomatic samples were collected and tested for the presence of a begomovirus using polymerase chain reaction (PCR) with the begomovirus-specific degenerate primer pair PAL1v1978/PAR1c715 (3). Samples were also tested for Cucumber mosaic virus (CMV), Potato virus Y (PVY), Tobacco etch virus (TEV), Pepper veinal mottle virus (PVMV), and Tomato mosaic virus (ToMV) using enzyme-linked immunosorbent assay (ELISA). All samples were negative for CMV, PVY, TEV, PVMV, and ToMV. However, the expected 1.4-kb PCR product for begomoviruses was obtained from all samples. DNA-B and DNA-beta were not detectable using PCR with the DNA-B specific primer pairs DNABLC1/DNABLV2 and DNABLC2/ DNABLV2 (2) and the DNA-beta primer pair Beta01/Beta02 (1), respectively. The 1.4-kb PCR product of one sample was cloned and sequenced. On the basis of the sequence of the 1.4-kb DNA product, specific primers were designed to complete the DNA-A sequence. The DNA-A consisted of 2,785 nucleotides (GenBank Accession No. DQ358913) and was found to contain the six predicted open reading frames (ORFs V1, V2, C1, C2, C3, and C4). A BLAST analysis was conducted with geminivirus sequences available in the GenBank database at the National Center for Biotechnology Information (Bethesda, MD), and DNAMAN software (Lynnon Corporation, Quebec, Canada) was used for further comparisons. The DNA-A sequence of the virus associated with yellow leaf curl disease of tomato from Ethiopia showed highest sequence identity (92%) with Tomato yellow leaf curl Mali virus (TYLCMLV; GenBank Accession No. AY502934). On the basis of the DNA-A sequence comparison and the ICTV demarcation of species at 89% sequence identity, the Ethiopian virus is a provisional strain of TYLCMLV described from Mali. To our knowledge, this is the first report of a begomovirus associated with tomato yellow leaf curl disease in Ethiopia. References: (1) R. W. Briddon et al. Mol. Biotechnol. 20:315, 2002. (2) S. K. Green et al. Plant Dis. 85:1286, 2001. (3) M. R. Rojas et al. Plant Dis. 77:340, 1993.

scholarly journals First Report of Tobacco as a Natural Host of Tomato yellow leaf curl virus in Spain

Plant Disease ◽  
2005 ◽  
Vol 89 (8) ◽  
pp. 910-910 ◽  
Author(s):  
M. I. Font ◽  
C. Córdoba ◽  
A. García ◽  
R. Santiago ◽  
C. Jordá
Keyword(s):  
Mosaic Virus ◽  
Simultaneous Detection ◽  
Tomato Yellow Leaf ◽  
Natural Host ◽  
Enzyme Linked Immunosorbent Assay ◽  
Yellow Leaf ◽  
Tobacco Plants ◽  
First Report ◽  
Leaf Curl Virus ◽  
Leaf Curl

Two begomovirus species, Tomato yellow leaf curl Sardinia virus (TYLCSV) and Tomato yellow leaf curl virus (TYLCV), have been identified as causal agents of tomato yellow leaf curl disease (TYLCD) in Spain. TYLCSV was reported in Spain in 1992 and TYLCV in 1997 on tomato crops (3). TYLCV was also reported in common bean (Phaseolus vulgaris L.) and pepper (Capsicum annuum L.) crops in southern Spain in 1997 and 1999, respectively. During the summer of 2004, symptoms of yellowing, crumpling, and necrosis of new leaves were observed sporadically in young, field-grown tobacco (Nicotiana tabacum L.) plants in the Badajoz Province. These tobacco plants were next to tomato crops where TYLCV was detected for the first time in Badajoz in 2003. In September 2004, four symptomatic tobacco plants were selected for double antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA) and polymerase chain reaction (PCR) identification analyses. Serological analyses were carried out in two repetitions and with the following polyclonal antisera: Potato virus Y (PVY) (Loewe Biochemica, Sauerlach, Germany); Tobacco mild green mosaic virus (produced in our laboratory); Tobacco mosaic virus (BIO-RAD, Marnes-La-Coquette, France); and Tomato spotted wilt virus (Loewe Biochemica). A simplified method of duplex PCR was used for a rapid, sensitive, and simultaneous detection of TYLCSV and TYLCV (2). Mixed infections of PVY and TYLCV were detected in all four tobacco samples tested. TYLCV infection was confirmed using the primer pair TY-1/TY-2 specific for the coat protein (CP) gene of begomoviruses (1). The CP fragment was digested with the restriction enzyme AvaII, and the pattern obtained corresponded to that obtained from TYLCV-infected tomato that served as a positive control. Two PCR products from different tobacco samples were sequenced and both showed 100% identity with the corresponding region (Almería) of TYLCV (GenBank Accession No. AJ489258) and 99% with TYLCV-Mild (Spain) (GenBank Accession No. AJ519441), confirming the diagnosis. The symptoms observed in the tobacco plants can not be attributed solely to TYLCV since the virus was present in a mixed infection with PVY. However, tobacco infected with TYLCV may serve as an important alternate host for TYLCV in the tomato cropping system. To our knowledge, this is the first report of N. tabacum as a natural host of TYLCV in Spain. References: (1) G. P. Accotto et al. Eur. J. Plant Pathol. 106:179, 2000. (2) P. Martínez-Culebras et al. Ann. Appl. Biol. 139:251, 2001. (3) J. Navas-Castillo et al. Plant Dis. 81:1461, 1997.

scholarly journals First Report of ‘Candidatus Phytoplasma pyri’ Causing Peach Yellow Leaf Roll (PYLR) in Spain

Plant Disease ◽  
2014 ◽  
Vol 98 (7) ◽  
pp. 989-989 ◽  
Author(s):  
J. Sabaté ◽  
A. Laviña ◽  
A. Batlle
Keyword(s):  
North America ◽  
Leaf Roll ◽  
Universal Primers ◽  
Yellow Leaf ◽  
Specific Primers ◽  
First Report ◽  
Wide Range ◽  
Pcr Products ◽  
Peach Trees ◽  
Prunus Spp

‘Candidatus Phytoplasma prunorum,’ which causes European stone fruit yellows (ESFY), is the prevalent phytoplasma affecting Prunus spp. in Europe. It is closely related to ‘Ca. P. pyri,’ which causes pear decline (PD) in pear trees. Both phytoplasma belong to the ribosomal group 16Sr-X and are naturally transmitted by different species of Cacopsylla spp. (4). In North America, ‘Ca. P. pyri’ is responsible for peach yellow leaf roll (PYLR), transmitted by Cacopsylla pyricola from pear to peach trees (1). In Spain, ‘Ca. P. prunorum’ is widespread on Prunus spp., but its occurrence on Prunus persicae is very low and ‘Ca. P. pyri’ is present in every pear orchard (3). During 2012, a previously unreported syndrome including early reddening, leaf curling, decline, abnormal fruits, and in some cases chlorosis and death of peach trees was reported on peach in Lleida, northern Spain. Symptoms were different to ESFY and PYLR, in that flowering disorders such as ESFY or yellows were not apparent, and reddening and decline were the most common symptoms. The disease was present in a wide range of varieties and rootstocks, suggesting insect transmission in an area where C. pruni, vector of ‘Ca. P. prunorum,’ was not previously reported, but C. pyri was abundant in pear orchards. Shoot samples from 20 symptomatic peach trees were collected in seven orchards within a 2 km2 area with an estimated incidence of 40%, which was higher in the borders. DNA was extracted from 1 g of leaf midribs and phloem tissue and amplified with ribosomal universal primers P1/P7 followed by nested PCR with R16F2n/R16R2 and specific primers fO1/rO1 that target the 16Sr-X group (3). The final PCR products were digested with RsaI enzyme. Amplifications with non-ribosomal specific primers, Imp ESFY, Imp PD A and Imp PD B that amplify sequences of gene Imp, that encode a phytoplasma membrane protein, were also carried out (2). Tissue samples with ESFY and PD and peach seedlings were used as positive and negative controls, respectively. Amplified PCR products were sequenced and compared to sequences deposited in GenBank. Phytoplasmas were detected in 18 of the 20 samples analyzed. No phytoplasmas were detected in negative peach controls. All digestions of fO1/rO1 PCR products from peach samples showed a PD profile, while no ESFY profile was detected. All samples were positive with specific primers Imp PD A and B. None of the peach samples were positive with the specific Imp-ESFY primers. Sequencing of R16 and Imp PDA and B amplicons revealed the presence of a stable isolate. The sequences were submitted to the European nucleotide archive (ENA) with the accession nos. HG737345 and HG737344. Based on the 16S rDNA sequence, this strain is 100% homologous to the reference strain PD1 (GenBank Accession No. AJ542543) and 99.55% homologous to strain PD 33 Lib (GenBank FN600725) based on the Imp gene sequence. This is the first report of PD phytoplasma in peach trees in Spain, and the first report in Europe of PD phytoplasma causing economically important outbreaks in peach orchards, following a pattern that could be similar to PYLR in North America. This strain is genetically closer to some European or Middle Eastern PDs than to North American PYLR. References: (1) C. L. Blomquist et al. Plant Dis. 86:759, 2002. (2) J. L. Danet et al. Microbiology 157:438, 2011. (3) M. Garcia-Chapa et al. J. Phytopathol. 151:584, 2003. (4) E. Seemüller et al. Int. J. Syst. Evol. Microbiol. 54:1217, 2004.

scholarly journals First Report of Nemesia ring necrosis virus in North America in Ornamental Plants from California

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1263-1263 ◽  
Author(s):  
D. M. Mathews ◽  
J. A. Dodds
Keyword(s):  
North America ◽  
Host Range ◽  
Ornamental Plants ◽  
Chenopodium Quinoa ◽  
Systemic Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Necrosis Virus ◽  
Specific Primers ◽  
First Report

During the last several years, two California propagators have detected what was believed to be the tymovirus Scrophularia mottle virus (ScrMV) in several ornamental plant species on the basis of enzyme-linked immunosorbent assay (ELISA) using a ScrMV antibody system. Symptoms were generally mild, ranging from nonsymptomatic to a mild mosaic. Our laboratory confirmed the presence of a tymovirus in one Verbena sp. and two Diascia spp. cultivars on the basis of dsRNA analysis that showed bands of approximately 6,400 and 300 nucleotides representing the genomic and coat protein subgenomic RNAs, respectively. While these plants and those that were experimentally infected (Nicotiana benthamiana and N. clevelandii) also tested positive for ScrMV by ELISA, the host range did not match that published for ScrMV, notably the lack of symptoms in Chenopodium quinoa and the lack of systemic infection in Datura stramonium. A similar host range result was reported in Europe for another tymovirus that cross reacts with ScrMV antiserum, Nemesia ring necrosis virus (NeRNV) (2). Using NeRNV specific primers (1), we used reverse transcription-polymerase chain reaction (RT-PCR) to test plants that had previously tested positive for ScrMV by ELISA and had dsRNAs typical of a tymovirus. An amplicon of the appropriate size (960 bp) for NeRNV was obtained from each of five samples. Using ScrMV specific primers, the same samples failed to amplify the expected product. We have found NeRNV in three Diascia spp., one Verbena sp., and one Nemesia sp. plants in two counties in California (Riverside and San Diego). When the RT-PCR products were sequenced, they all had 99% sequence identities to NeRNV with 4 to 7 single nucleotide changes (GenBank Accession Nos. DQ648150 to DQ648154). Notably, each of the five amplicons had changes at nucleotides 5134 (G to C) and 5549 (G to T) when compared with the European isolates of NeRNV, which did not result in any amino acid changes. To our knowledge, this is the first report of NeRNV in North America and more specifically, in California. References: (1) R. Koenig et al. J. Gen. Virol. 86:1827, 2005. (2) A. L. Skelton et al. Plant Pathol. 53:798, 2004.

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