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Robert L. Gilbertson - One of the best experts on this subject based on the ideXlab platform.
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Rasta Disease of Tomato in Ghana is Caused by the PospiViroids Potato spindle tuber Viroid and Tomato apical stunt Viroid.
Plant disease, 2019Co-Authors: Ozgur Batuman, Ö Cem Çiftçi, M. K. Osei, Sally A. Miller, Maria R. Rojas, Robert L. GilbertsonAbstract:Rasta is a virus-like disease of unknown etiology affecting tomato (Solanum lycopersicum) plants in Ghana. Symptoms include stunting; epinasty, crumpling, and chlorosis of leaves; and necrosis of leaf veins, petioles, and stems. Leaf samples with rasta symptoms were collected from commercial tomato fields in Ghana in October 2012 and applied to FTA cards, and RNA extracts were prepared. Reverse-transcription polymerase chain reaction (RT-PCR) tests with primers for Columnea Latent Viroid, which causes rasta-like symptoms in tomato plants in Mali, were negative, whereas tests with degenerate Viroid primer pairs were inconclusive. However, tomato seedlings (Early Pak 7) mechanically inoculated with RNA extracts of 10 of 13 samples developed rasta-like symptoms. In RT-PCR tests with RNA from leaves of the 10 symptomatic seedlings and primers for Potato spindle tuber Viroid (PSTVd) or Tomato apical stunt Viroid (TASVd), the expected size (approximately 360 bp) of DNA fragment was amplified from eight and two seedlings, respectively. Sequence analyses confirmed that these fragments were from PSTVd and TASVd isolates, and revealed a single PSTVd haplotype and two TASVd haplotypes. The PSTVd and TASVd isolates from Ghana had high nucleotide identities (>94%) with isolates from other geographic regions. In a host range study, PSTVd and TASVd isolates from Ghana induced rasta symptoms in the highly susceptible tomato cultivar Early Pak 7 and mild or no symptoms in Glamour, and symptomless infections in a number of other solanaceous species. PSTVd and TASVd isolates were seed associated and possibly seed transmitted.
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First Report of Columnea Latent Viroid (CLVd) in Tomato in Mali.
Plant disease, 2013Co-Authors: Ozgur Batuman, Robert L. GilbertsonAbstract:During surveys of tomato (Solanum lycopersicum) fields in Niono, Mali, conducted in March 2011, unusual disease symptoms, including stunted growth, epinasty, and chlorosis of leaves and necrosis of leaf veins and stems were observed in multiple fields. The incidence of these symptoms was low (~1 to 5%), but they were distinct from those associated with known diseases in the region. A representative leaf sample with these symptoms was applied to filter paper (FTA cards, Whatman), and DNA and RNA extracts were prepared according to manufacturer instructions. RT-PCR tests for Tomato spotted wilt virus, Tobacco streak virus, Tomato necrotic spot virus, Tobacco/tomato mosaic viruses, Cucumber mosaic virus, Alfalfa mosaic virus, torradoviruses, and potyviruses, and PCR tests for begomoviruses, phytoplasmas, and 'Candidatus Liberibacter' infection were also negative. However, virus-like symptoms developed in all 16 tomato seedlings (cv. Early Pak 7) 7 to 10 days after mechanical (sap) inoculation with inoculum prepared from the FTA sample. No symptoms developed in mock-inoculated control plants (n = 3). Symptoms induced included stunted growth and severe epinasty of leaves, followed by necrosis of leaf veins, petioles, and stems. These symptoms were similar to those observed in plants in Mali. When RNA extracts prepared from leaves of these symptomatic plants were mechanically inoculated onto 24 tomato seedlings, similar symptoms developed in all plants, suggesting the causal agent might be a Viroid. RT-PCR tests with RNA from symptomatic tomato leaves and universal (3) and various specific PospiViroid primer pairs were negative. However, equivalent RT-PCR tests conducted with the pCLV4/pCLVR4 primer pair specific for Columnea Latent Viroid (CLVd) (2) generated a DNA fragment of the expected size (~370 bp). The sequence of this DNA fragment (GenBank Accession No. JQ362419) was 99% identical with those of CLVd isolates from the Netherlands (AY373446 and AY372396). In host range studies, the CLVd isolate from Mali induced symptoms in all 48 mechanically-inoculated tomato plants, whereas no symptoms developed (up to 90 days after inoculation) in inoculated Chenopodium quinoa, C. amaranticolor, Nicotiana benthamiana, N. tabacum (cvs. Havana, Glurk and Turkish), N. glutinosa, Datura stramonium, common bean (cvs. Topcrop and Pinto bean), pumpkin (cv. Small Sugar), pepper (Capsicum annuum, cv. Yolo Wonder) and cucumber (cvs. Emparator and Poinsett 76) plants (results of three independent experiments with six plants per experiment). Symptomless infections were detected in pepper (24 of 30), N. benthamiana (25 of 25), and N. tabacum cv. Turkish (11 of 24) plants by RT-PCR with the pCLV4/pCLVR4 primer pair. To our knowledge, this is the first report of CLVd infecting tomato in Mali. RT-PCR tests of seeds collected from CLVd-infected tomato, pepper, and N. benthamiana plants also detected CLVd (1). Thus, it is possible that CLVd was introduced into Mali in association with seed. References: (1) O. Batuman and R. L. Gilbertson. Phytopathology 102:S4.9, 2012. (2) R. L. Spieker. Arch. Virol. 141:1823, 1996. (3) J. T. J. Verhoeven et al. Eur. J. Plant Pathol. 110:823, 2004.
R. L. Spieker - One of the best experts on this subject based on the ideXlab platform.
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A Viroid fromBrunfelsia undulata closely related to theColumnea Latent Viroid
Archives of Virology, 1996Co-Authors: R. L. SpiekerAbstract:A Viroid was isolated from symptomless Brunfelsia undulata plants using the bidirectional PAGE method for analysis of small circular RNA molecules. The Viroid was transmitted to tomato by mechanical inoculation. Infected tomato plants developed symptoms smilar to those caused by intermediate strains of potato spindle tuber Viroid (PSTVd). Cloning and sequencing revealed that the Viroid from Brunfelsia undulata is closely related to the Columnea Latent Viroid (CLVd). Therefore, the new Viroid sequence variant has been named CLVd-B. The Brunfelsia Viroid CLVd-B consists of 373 nucleotides, 215 G + C, 158 A + U with a GC content of 57.6%. The most stable rod-like secondary structure of this Viroid has 80 G:C, 39 A:U and 11 G:U base pairs with a minimum free energy of −157.2 kcal/mol (−657.1 kJ/mol). The sequence similarity of the right terminal domain of CLVd-B and of tomato apical stunt Viroid (TASVd) is higher than the sequence similarity of these domains comparing CLVd and TASVd.
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A Viroid from Brunfelsia undulata closely related to the Columnea Latent Viroid.
Archives of Virology, 1996Co-Authors: R. L. SpiekerAbstract:A Viroid was isolated from symptomlessBrunfelsia undulata plants using the bidirectional PAGE method for analysis of small circular RNA molecules. The Viroid was transmitted to tomato by mechanical inoculation. Infected tomato plants developed symptoms smilar to those caused by intermediate strains of potato spindle tuber Viroid (PSTVd). Cloning and sequencing revealed that the Viroid fromBrunfelsia undulata is closely related to theColumnea Latent Viroid (CLVd). Therefore, the new Viroid sequence variant has been named CLVd-B. TheBrunfelsia Viroid CLVd-B consists of 373 nucleotides, 215 G + C, 158 A + U with a GC content of 57.6%. The most stable rod-like secondary structure of this Viroid has 80 G:C, 39 A:U and 11 G:U base pairs with a minimum free energy of −157.2 kcal/mol (−657.1 kJ/mol). The sequence similarity of the right terminal domain of CLVd-B and of tomato apical stunt Viroid (TASVd) is higher than the sequence similarity of these domains comparing CLVd and TASVd.
J W Roenhorst - One of the best experts on this subject based on the ideXlab platform.
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Development and validation of a real-time RT-PCR test for screening pepper and tomato seed lots for the presence of pospiViroids.
PloS one, 2020Co-Authors: Marleen Botermans, J W Roenhorst, Jacobus Th J Verhoeven, M. Hooftman, Eveline Metz, Esther J. Van Veen, Bart P. J. Geraats, Mark Kemper, Debora C. M. Beugelsdijk, Harrie KoenraadtAbstract:Potato spindle tuber Viroid and other pospiViroids can cause serious diseases in potato and tomato crops. Consequently, pospiViroids are regulated in several countries. Since seed transmission is considered as a pathway for the introduction and spread of pospiViroids, some countries demand for the testing of seed lots of solanaceous crops for the presence of pospiViroids. A real-time RT-PCR test, named PospiSense, was developed for testing pepper (Capsicum annuum) and tomato (Solanum lycopersicum) seeds for seven pospiViroid species known to occur naturally in these crops. The test consists of two multiplex reactions running in parallel, PospiSense 1 and PospiSense 2, that target Citrus exocortis Viroid (CEVd), Columnea Latent Viroid (CLVd), pepper chat fruit Viroid (PCFVd), potato spindle tuber Viroid (PSTVd), tomato apical stunt Viroid (TASVd), tomato chlorotic dwarf Viroid (TCDVd) and tomato planta macho Viroid (TPMVd, including the former Mexican papita Viroid). Dahlia Latent Viroid (DLVd) is used as an internal isolation control. Validation of the test showed that for both pepper and tomato seeds the current requirements of a routine screening test are fulfilled, i.e. the ability to detect one infested seed in a sample of c.1000 seeds for each of these seven pospiViroids. Additionally, the PospiSense test performed well in an inter-laboratory comparison, which included two routine seed-testing laboratories, and as such provides a relatively easy alternative to the currently used tests.
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PospiViroid infections in Capsicum annuum: disease symptoms and lack of seed transmission
European Journal of Plant Pathology, 2020Co-Authors: J. Th. J. Verhoeven, Harrie Koenraadt, A. Jodlowska, L. Hüner, J W RoenhorstAbstract:Four pospiViroids, Columnea Latent Viroid (CLVd), pepper chat fruit Viroid (PCFVd), potato spindle tuber Viroid (PSTVd) and tomato apical stunt Viroid (TASVd), were mechanically inoculated on Capsicum annuum (pepper) cv. Yolo Wonder. Symptoms were different, though most pronounced for PCFVd, i.e. delay in flower and fruit onset, increase of plant height, and reduction of fruit size. For studying seed transmission, seeds with high loads of infectious Viroid were sown at different time intervals after harvesting, i.e. 0, 2 and 77 days. No transmission from seed to seedlings was recorded in a total of 765 seedlings, irrespective Viroid species and time interval. For PCFVd, the experiment was repeated in another pepper cultivar with the similar outcome for 179 seedlings. The results of this study are discussed in view of the role of infested seed lots in causing outbreaks in practice.
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Development and validation of a real-time RT-PCR assay for generic detection of pospiViroids.
Journal of virological methods, 2012Co-Authors: Marleen Botermans, J W Roenhorst, M. Hooftman, J. Th. J. Verhoeven, B.t.l.h. Van De Vossenberg, R. Dekter, E. T. M. MeekesAbstract:In many countries phytosanitary regulations apply to Potato spindle tuber Viroid, because it can cause serious diseases in potato and tomato crops. Other pospiViroids, some of which are distributed widely in ornamental crops, can cause similar diseases. Consequently, there is a need for a reliable and cost-effective generic testing method. An assay was developed that detects all known species of the genus PospiViroid, using real-time RT-PCR based on TaqMan technology. This GenPospi assay consists of two reactions running in parallel, the first targeting all pospiViroids, except Columnea Latent Viroid, the second specifically targeting the latter Viroid (already published). To monitor the RNA extraction a nad5 internal control was included. Method validation on tomato leaves showed that the GenPospi assay detects all pospiViroids up to a relative infection rate of 0.13% (equals 770 times dilution). The assay was specific because no cross reactivity was observed with other Viroids, viruses or nucleic acid from plant hosts. Repeatability and reproducibility were 100% and the assay appeared robust in an inter-laboratory comparison. The GenPospi assay has been shown to be a suitable tool for large-scale screening for all known pospiViroids. Although it has been validated for tomato leaves it can potentially be used for any crop.
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natural infections of tomato by citrus exocortis Viroid Columnea Latent Viroid potato spindle tuber Viroid and tomato chlorotic dwarf Viroid
European Journal of Plant Pathology, 2004Co-Authors: Th J J Verhoeven, C C C Jansen, T M Willemen, Robert A Owens, J W RoenhorstAbstract:Since 1988, Viroids have been occasionally detected in samples of tomato (Lycopersicon esculentum) originating both in the Netherlands and other countries. Infected plants showed chlorosis, bronzing, leaf distortion and growth reduction. Initial diagnosis of these Viroids was by return-polyacrylamide gel electrophoresis, which did not allow a further identification. This paper reports the identification of these Viroids by reverse transcription-polymerase chain reaction and sequence analysis. Three known Viroids of tomato, i.e. Citrus exocortis Viroid, Potato spindle tuber Viroid and Tomato chlorotic dwarf Viroid were identified. In addition, six isolates were identified as Columnea Latent Viroid, a Viroid so far only detected in some ornamental species. Like the isolates previously isolated from ornamental species, the isolates from tomato share genetic characteristics of both the genera HostuViroid and PospiViroid. The biological characteristics of all four Viroids, especially their potential effects on both potato (Solanum tuberosum) and tomato, stress the need for reconsideration of their phytosanitary risks.
Harrie Koenraadt - One of the best experts on this subject based on the ideXlab platform.
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Development and validation of a real-time RT-PCR test for screening pepper and tomato seed lots for the presence of pospiViroids.
PloS one, 2020Co-Authors: Marleen Botermans, J W Roenhorst, Jacobus Th J Verhoeven, M. Hooftman, Eveline Metz, Esther J. Van Veen, Bart P. J. Geraats, Mark Kemper, Debora C. M. Beugelsdijk, Harrie KoenraadtAbstract:Potato spindle tuber Viroid and other pospiViroids can cause serious diseases in potato and tomato crops. Consequently, pospiViroids are regulated in several countries. Since seed transmission is considered as a pathway for the introduction and spread of pospiViroids, some countries demand for the testing of seed lots of solanaceous crops for the presence of pospiViroids. A real-time RT-PCR test, named PospiSense, was developed for testing pepper (Capsicum annuum) and tomato (Solanum lycopersicum) seeds for seven pospiViroid species known to occur naturally in these crops. The test consists of two multiplex reactions running in parallel, PospiSense 1 and PospiSense 2, that target Citrus exocortis Viroid (CEVd), Columnea Latent Viroid (CLVd), pepper chat fruit Viroid (PCFVd), potato spindle tuber Viroid (PSTVd), tomato apical stunt Viroid (TASVd), tomato chlorotic dwarf Viroid (TCDVd) and tomato planta macho Viroid (TPMVd, including the former Mexican papita Viroid). Dahlia Latent Viroid (DLVd) is used as an internal isolation control. Validation of the test showed that for both pepper and tomato seeds the current requirements of a routine screening test are fulfilled, i.e. the ability to detect one infested seed in a sample of c.1000 seeds for each of these seven pospiViroids. Additionally, the PospiSense test performed well in an inter-laboratory comparison, which included two routine seed-testing laboratories, and as such provides a relatively easy alternative to the currently used tests.
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PospiViroid infections in Capsicum annuum: disease symptoms and lack of seed transmission
European Journal of Plant Pathology, 2020Co-Authors: J. Th. J. Verhoeven, Harrie Koenraadt, A. Jodlowska, L. Hüner, J W RoenhorstAbstract:Four pospiViroids, Columnea Latent Viroid (CLVd), pepper chat fruit Viroid (PCFVd), potato spindle tuber Viroid (PSTVd) and tomato apical stunt Viroid (TASVd), were mechanically inoculated on Capsicum annuum (pepper) cv. Yolo Wonder. Symptoms were different, though most pronounced for PCFVd, i.e. delay in flower and fruit onset, increase of plant height, and reduction of fruit size. For studying seed transmission, seeds with high loads of infectious Viroid were sown at different time intervals after harvesting, i.e. 0, 2 and 77 days. No transmission from seed to seedlings was recorded in a total of 765 seedlings, irrespective Viroid species and time interval. For PCFVd, the experiment was repeated in another pepper cultivar with the similar outcome for 179 seedlings. The results of this study are discussed in view of the role of infested seed lots in causing outbreaks in practice.
Ozgur Batuman - One of the best experts on this subject based on the ideXlab platform.
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Rasta Disease of Tomato in Ghana is Caused by the PospiViroids Potato spindle tuber Viroid and Tomato apical stunt Viroid.
Plant disease, 2019Co-Authors: Ozgur Batuman, Ö Cem Çiftçi, M. K. Osei, Sally A. Miller, Maria R. Rojas, Robert L. GilbertsonAbstract:Rasta is a virus-like disease of unknown etiology affecting tomato (Solanum lycopersicum) plants in Ghana. Symptoms include stunting; epinasty, crumpling, and chlorosis of leaves; and necrosis of leaf veins, petioles, and stems. Leaf samples with rasta symptoms were collected from commercial tomato fields in Ghana in October 2012 and applied to FTA cards, and RNA extracts were prepared. Reverse-transcription polymerase chain reaction (RT-PCR) tests with primers for Columnea Latent Viroid, which causes rasta-like symptoms in tomato plants in Mali, were negative, whereas tests with degenerate Viroid primer pairs were inconclusive. However, tomato seedlings (Early Pak 7) mechanically inoculated with RNA extracts of 10 of 13 samples developed rasta-like symptoms. In RT-PCR tests with RNA from leaves of the 10 symptomatic seedlings and primers for Potato spindle tuber Viroid (PSTVd) or Tomato apical stunt Viroid (TASVd), the expected size (approximately 360 bp) of DNA fragment was amplified from eight and two seedlings, respectively. Sequence analyses confirmed that these fragments were from PSTVd and TASVd isolates, and revealed a single PSTVd haplotype and two TASVd haplotypes. The PSTVd and TASVd isolates from Ghana had high nucleotide identities (>94%) with isolates from other geographic regions. In a host range study, PSTVd and TASVd isolates from Ghana induced rasta symptoms in the highly susceptible tomato cultivar Early Pak 7 and mild or no symptoms in Glamour, and symptomless infections in a number of other solanaceous species. PSTVd and TASVd isolates were seed associated and possibly seed transmitted.
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First Report of Columnea Latent Viroid (CLVd) in Tomato in Mali.
Plant disease, 2013Co-Authors: Ozgur Batuman, Robert L. GilbertsonAbstract:During surveys of tomato (Solanum lycopersicum) fields in Niono, Mali, conducted in March 2011, unusual disease symptoms, including stunted growth, epinasty, and chlorosis of leaves and necrosis of leaf veins and stems were observed in multiple fields. The incidence of these symptoms was low (~1 to 5%), but they were distinct from those associated with known diseases in the region. A representative leaf sample with these symptoms was applied to filter paper (FTA cards, Whatman), and DNA and RNA extracts were prepared according to manufacturer instructions. RT-PCR tests for Tomato spotted wilt virus, Tobacco streak virus, Tomato necrotic spot virus, Tobacco/tomato mosaic viruses, Cucumber mosaic virus, Alfalfa mosaic virus, torradoviruses, and potyviruses, and PCR tests for begomoviruses, phytoplasmas, and 'Candidatus Liberibacter' infection were also negative. However, virus-like symptoms developed in all 16 tomato seedlings (cv. Early Pak 7) 7 to 10 days after mechanical (sap) inoculation with inoculum prepared from the FTA sample. No symptoms developed in mock-inoculated control plants (n = 3). Symptoms induced included stunted growth and severe epinasty of leaves, followed by necrosis of leaf veins, petioles, and stems. These symptoms were similar to those observed in plants in Mali. When RNA extracts prepared from leaves of these symptomatic plants were mechanically inoculated onto 24 tomato seedlings, similar symptoms developed in all plants, suggesting the causal agent might be a Viroid. RT-PCR tests with RNA from symptomatic tomato leaves and universal (3) and various specific PospiViroid primer pairs were negative. However, equivalent RT-PCR tests conducted with the pCLV4/pCLVR4 primer pair specific for Columnea Latent Viroid (CLVd) (2) generated a DNA fragment of the expected size (~370 bp). The sequence of this DNA fragment (GenBank Accession No. JQ362419) was 99% identical with those of CLVd isolates from the Netherlands (AY373446 and AY372396). In host range studies, the CLVd isolate from Mali induced symptoms in all 48 mechanically-inoculated tomato plants, whereas no symptoms developed (up to 90 days after inoculation) in inoculated Chenopodium quinoa, C. amaranticolor, Nicotiana benthamiana, N. tabacum (cvs. Havana, Glurk and Turkish), N. glutinosa, Datura stramonium, common bean (cvs. Topcrop and Pinto bean), pumpkin (cv. Small Sugar), pepper (Capsicum annuum, cv. Yolo Wonder) and cucumber (cvs. Emparator and Poinsett 76) plants (results of three independent experiments with six plants per experiment). Symptomless infections were detected in pepper (24 of 30), N. benthamiana (25 of 25), and N. tabacum cv. Turkish (11 of 24) plants by RT-PCR with the pCLV4/pCLVR4 primer pair. To our knowledge, this is the first report of CLVd infecting tomato in Mali. RT-PCR tests of seeds collected from CLVd-infected tomato, pepper, and N. benthamiana plants also detected CLVd (1). Thus, it is possible that CLVd was introduced into Mali in association with seed. References: (1) O. Batuman and R. L. Gilbertson. Phytopathology 102:S4.9, 2012. (2) R. L. Spieker. Arch. Virol. 141:1823, 1996. (3) J. T. J. Verhoeven et al. Eur. J. Plant Pathol. 110:823, 2004.