First Report of Tomato spotted wilt virus Infecting Onion and Garlic in Serbia

In June 2011, extensive bleaching and numerous small whitish spots on leaves were observed in an onion (Allium cepa) seed crop as well as chlorotic spots and streaks in the neighboring garlic (A. sativum) bulb crop in the Aleksandrovo locality (Central Banat District, Serbia). Affected plants occurred throughout the field and disease incidence was estimated at 60% in the onion and 40% in the garlic crop. A high population of Thrips tabaci that was found in both crops, and local necrotic spots on Petunia × hybrida mechanically inoculated with infected onion or garlic sap by a chilled 0.01 M phosphate buffer, pH 7.0, containing 0.1% sodium sulfite (1), suggested the presence of a Tospovirus. For these reasons, sampled symptomatic onion and garlic plants were tested for the presence of Tomato spotted wilt virus (TSWV) and Iris yellow spot virus (IYSV) using commercial double-antibody sandwich-ELISA diagnostic kits (Bioreba AG, Reinach, Switzerland). Commercial positive and negative controls and extracts from healthy onion and garlic tissue were included in each ELISA. Of the 18 onion and 10 garlic plants tested, 16 and 7 samples, respectively, were positive for TSWV, and all were negative for IYSV. The identity of TSWV was further confirmed by conventional reverse transcription (RT)-PCR analysis. Total RNAs were extracted with an RNeasy Plant Mini Kit (Qiagen, Hilden, Germany) and RT-PCR was performed with the One-Step RT-PCR Kit (Qiagen) using TSWV-specific forward (5′-GGTTAAGCTCACTAAGAAARCA-3′) and reverse primers (5′-TTTAACYCCRAACATTTCATAGA-3′), designed to amplify a 738-bp fragment of the nucleocapsid protein (N) gene. Total RNAs obtained from plants infected with a Serbian isolate of TSWV (GenBank Accession No. GQ373173) and healthy onion garlic plants were used as positive and negative controls, respectively. An amplicon of the expected size was produced from the 16 onion and 7 garlic ELISA-positive plants, but not from healthy controls. The amplified products derived from the two selected isolates, 114-11 from onion and 115-11 from garlic, were sequenced directly after purification with the QIAquick PCR Purification kit (Qiagen); the sequences obtained were allocated GenBank Accession Nos. JQ619234 and JQ619235, respectively. Sequence analysis of the partial N gene, conducted with MEGA5 software (4), revealed 99.9% nucleotide identity (100% amino acid identity) between the two Serbian Allium isolates. Serbian onion and garlic isolates showed the highest nucleotide identities of 100% and 99.9% with Serbian summer squash isolate (JF303081) and tobacco isolate from Montenegro (GU369729), respectively. Well-established in many European countries, TSWV has been reported as an important constraint to the production of tomato, pepper, tobacco, and ornamentals (2), but the information on TSWV naturally infecting Allium spp. is limited. The presence of TSWV on onion and garlic in Serbia revealed that its known host range has expanded in Europe. To our knowledge, other than Marchoux's unpublished data (3), there are no other reports of garlic as a natural host of TSWV. The TSWV presence on Allium spp. represents a serious threat for these crops in Serbia, considering that it is prevalent in other crops in the area and its vectors are widespread. References: (1) Anonymous. OEPP/EPPO Bull. 34:271, 2004. (2) H. R. Pappu et al. Virus Res. 141:219, 2009. (3) G. Parrella et al. J. Plant Pathol. 85:227, 2003. (4) K. Tamura et al. Mol. Biol. Evol. 28:2731, 2011.

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First Report of Tomato spotted wilt virus on Chrysanthemum in Serbia

Plant Disease ◽

10.1094/pdis-08-12-0778-pdn ◽

2013 ◽

Vol 97 (1) ◽

pp. 150-150 ◽

Cited By ~ 7

Author(s):

I. Stanković ◽

A. Bulajić ◽

A. Vučurović ◽

D. Ristić ◽

K. Milojević ◽

...

Keyword(s):

Tomato Spotted Wilt Virus ◽

Disease Incidence ◽

N Gene ◽

Impatiens Necrotic Spot Virus ◽

Maximum Parsimony Tree ◽

Rt Pcr ◽

First Report ◽

Tomato Spotted Wilt ◽

Negative Controls ◽

Wilt Virus

In July 2011, greenhouse-grown chrysanthemum hybrid plants (Chrysanthemum × morifolium) with symptoms resembling those associated with tospoviruses were observed in the Kupusina locality (West Bačka District, Serbia). Disease incidence was estimated at 40%. Symptomatic plants with chlorotic ring spots and line patterns were sampled and tested by double antibody sandwich (DAS)-ELISA using polyclonal antisera (Bioreba AG, Reinach, Switzerland) against the two of the most devastating tospoviruses in the greenhouse floriculture industry: Tomato spotted wilt virus (TSWV) and Impatiens necrotic spot virus (INSV) (2). Commercial positive and negative controls and extracts from healthy chrysanthemum tissue were included in each ELISA. TSWV was detected serologically in 16 of 20 chrysanthemum samples and all tested samples were negative for INSV. The virus was mechanically transmitted from ELISA-positive chrysanthemum samples to five plants each of both Petunia × hybrida and Nicotiana tabacum ‘Samsun’ using chilled 0.01 M phosphate buffer (pH 7) containing 0.1% sodium sulfite. Inoculated plants produced local necrotic spots and systemic chlorotic/necrotic concentric rings, consistent with symptoms caused by TSWV (1). The presence of TSWV in ELISA-positive chrysanthemum plants and N. tabacum‘Samsun’ was further confirmed by conventional reverse transcription (RT)-PCR. Total RNAs were extracted with an RNeasy Plant Mini Kit (Qiagen, Hilden, Germany). RT-PCR was performed with the One-Step RT-PCR Kit (Qiagen) using primers TSWVCP-f/TSWVCP-r specific to the nucleocapsid protein (N) gene (4). A Serbian isolate of TSWV from tobacco (GenBank Accession No. GQ373173) and RNA extracted from a healthy chrysanthemum plant were used as positive and negative controls, respectively. An amplicon of the correct predicted size (738-bp) was obtained from each of the plants assayed, and that derived from chrysanthemum isolate 529-11 was purified (QIAqick PCR Purification Kit, Qiagen) and sequenced (JQ692106). Sequence analysis of the partial N gene, conducted with MEGA5 software, revealed the highest nucleotide identity of 99.6% (99% amino acid identity) with 12 TSWV isolates deposited in GenBank originating from different hosts from Italy (HQ830186-87, DQ431237-38, DQ398945), Montenegro (GU355939-40, GU339506, GU339508), France (FR693055-56), and the Czech Republic (AJ296599). The consensus maximum parsimony tree obtained on a 705-bp partial N gene sequence of TSWV isolates available in GenBank revealed that Serbian TSWV isolate 529-11 from chrysanthemum was clustered in the European subpopulation 2, while the Serbian isolates from tomato (GU369723) and tobacco (GQ373172-73 and GQ355467) were clustered in the European subpopulation 1 denoted previously (3). The distribution of TSWV in commercial chrysanthemum crops is wide (2). To our knowledge, this is the first report of TSWV infecting chrysanthemum in Serbia. Since chrysanthemum popularity and returns have been rising rapidly, the presence of TSWV may significantly reduce quality of crops in Serbia. References: (1) Anonymous. OEPP/EPPO Bull. 34:271, 2004. (2) Daughtrey et al. Plant Dis. 81:1220, 1997. (3) I. Stanković et al. Acta Virol. 55:337, 2011. (4) A. Vučurović et al. Eur. J. Plant Pathol. 133:935, 2012.

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First Report of Tomato spotted wilt virus on Brugmansia sp. in Serbia

Plant Disease ◽

10.1094/pdis-10-12-0937-pdn ◽

2013 ◽

Vol 97 (6) ◽

pp. 850-850 ◽

Cited By ~ 3

Author(s):

D. Nikolić ◽

I. Stanković ◽

A. Vučurović ◽

D. Ristić ◽

K. Milojević ◽

...

Keyword(s):

Mosaic Virus ◽

Tomato Spotted Wilt Virus ◽

N Gene ◽

Broad Host Range ◽

Rt Pcr ◽

First Report ◽

Tomato Spotted Wilt ◽

Plant Pathol ◽

Negative Controls ◽

Wilt Virus

Brugmansia (Brugmansia spp.), also known as Angel's trumpet, is a perennial shrub in the Solanaceae that is a popular landscape plant in the tropics and subtropics, and potted plant in temperate regions. In April 2012, virus-like symptoms including chlorotic leaf patterns and curling followed by necrosis and distortion of leaves were observed on five outdoor-grown brugmansia plants in a private garden in Mackovac, Rasina District, Serbia. Symptomatic leaves were tested for the presence of several common ornamental viruses including Tomato spotted wilt virus (TSWV), Impatiens necrotic spot virus (INSV), Cucumber mosaic virus (CMV), and Tobacco mosaic virus (TMV) by commercial double-antibody sandwich (DAS)-ELISA diagnostic kits (Bioreba AG, Reinach, Switzerland). Commercial positive and negative controls and extract from healthy brugmansia leaves were included in each ELISA. TSWV was detected serologically in all five brugmansia samples and all tested samples were negative for INSV, CMV, and TMV. The virus was mechanically transmitted from an ELISA-positive sample (41-12) to five plants of each Petuina × hybrida and Nicotiana glutinosa. Inoculated P. × hybrida plants showed local necrotic lesions and N. glutinosa showed mosaic and systemic necrosis 4 and 12 days post-inoculation, respectively, which were consistent with symptoms caused by TSWV (1). For further confirmation of TSWV infection, reverse transcription (RT)-PCR was performed with the OneStep RT-PCR (Qiagen, Hilden, Germany) using a set of TSWV-specific primers, TSWV CP-f and TSWV CP-r (4), designed to amplify a 738-bp fragment of the nucleocapsid protein (N) gene. Total RNAs from naturally infected brugmansia and symptomatic N. glutinosa plants were extracted using the RNeasy Plant Mini Kit (Qiagen). Total RNAs obtained from the Serbian tobacco isolate of TSWV (GenBank Accession No. GQ373173) and healthy brugmansia plants were used as positive and negative controls, respectively. The expected size of the RT-PCR product was amplified from symptomatic brugmansia and N. glutinosa but not from healthy tissues. The amplified product derived from the isolate 41-12 was sequenced directly after purification with the QIAquick PCR Purification kit (Qiagen), deposited in GenBank (JX468080), and subjected to sequence analysis by MEGA5 software (3). Sequence comparisons revealed that the Serbian isolate 41-12 shared the highest nucleotide identity of 99.9% (99.5% amino acid identity) with an Italian TSWV isolate P105/2006RB (DQ915946) originating from pepper. To our knowledge, this is the first report of TSWV on brugmansia in Serbia. Due to the increasing popularity and economic importance of brugmansia as an ornamental crop, thorough inspections and subsequent testing for TSWV and other viruses are needed. This high-value ornamental plant may act also as reservoir for the virus that can infect other ornamentals and cultivated crops, considering that TSWV has a very broad host range (2). References: (1) Anonymous. OEPP/EPPO Bull. 34:271, 2004. (2) G. Parrella et al. J. Plant Pathol. 85:227, 2003. (3) K. Tamura et al. Mol. Biol. Evol. 28:2731, 2011. (4) A. Vučurović et al. Eur. J. Plant Pathol. 133:935, 2012.

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First Report of Tomato spotted wilt virus on Pepper in Montenegro

Plant Disease ◽

10.1094/pdis-03-11-0167 ◽

2011 ◽

Vol 95 (7) ◽

pp. 882-882 ◽

Cited By ~ 5

Author(s):

J. Zindović ◽

A. Bulajić ◽

B. Krstić ◽

M. Ciuffo ◽

P. Margaria ◽

...

Keyword(s):

Amino Acid ◽

Tomato Spotted Wilt Virus ◽

Nucleotide Identity ◽

N Gene ◽

Rt Pcr ◽

First Report ◽

Tomato Spotted Wilt ◽

Italian Isolate ◽

Negative Controls ◽

Wilt Virus

In April 2009, chlorotic and necrotic ring spots, chlorotic line patterns, and stunting were observed on greenhouse-grown pepper plants in the vicinity of Podgorica, Montenegro. Disease symptom incidence was estimated at 40%. Symptomatic leaves were tested for the presence of Tomato spotted wilt virus (TSWV) with a commercial double-antibody sandwich (DAS)-ELISA diagnostic kit (Bioreba AG, Reinach, Switzerland). Commercial positive and negative controls were included in each ELISA. TSWV was detected serologically in 33 of 75 pepper samples. The virus was mechanically transmitted from ELISA-positive pepper samples to Nicotiana tabacum cv. Samsun using chilled 0.05 M phosphate buffer (pH 7) containing 0.1% sodium sulfite (1). Inoculated test plants produced chlorotic and necrotic concentric rings and necrotic spots, consistent with symptoms caused by TSWV on N. tabacum. For further confirmation of TSWV infection, reverse transcription (RT)-PCR was performed with the One-Step RT-PCR Kit (Qiagen, Hilden, Germany) using three sets of primers: S70-for/S890-rev (2) and S574-for/S1433-rev (3), both specific to the nonstructural (NSs) gene; and S1983-for/S2767-rev (2), specific to the nucleocapsid protein (N) gene. Total RNAs from naturally infected pepper and symptomatic N. tabacum cv. Samsun plants were extracted with the RNeasy Plant Mini Kit (Qiagen, Hilden, Germany). Total RNAs obtained from the Italian isolate of TSWV (GenBank Accession No. DQ398945) and healthy tobacco plants were used as positive and negative controls, respectively. The expected sizes of the RT-PCR products (820, 859, and 784 bp) were amplified from symptomatic pepper samples but not from healthy tissues. The PCR product obtained from isolate Is-344 using primers specific to N gene was purified by a QIAquick PCR Purification Kit (Qiagen), cloned into the pGEM-T Easy Vector (Promega, Madison, WI) and sequenced in both directions using the same primer pair as in RT-PCR. The sequences amplified with the two primer pairs specific to the NSs gene were obtained by direct sequencing (Bio-Fab Research Srl, Pomezia, Italy) and joined using MEGA4 software. Sequence analysis of the complete N gene (777 bp; GenBank Accession No. GU369717) revealed that the TSWV isolate originating from Montenegro shared 98.2 to 99.7% nucleotide identity (98.1 to 100% amino acid identities) with corresponding TSWV sequences deposited in GenBank. The Montenegrin isolate Is-344 was most closely related to Italian isolates from tomato (GU369725) and eggplant (GU369720). The partial (1,257 bp) nucleotide sequence of NSs gene (GU369737) showed 96 to 99.8% nucleotide identity (96.9 to 100% amino acid identity) with previously reported TSWV sequences, and in this case the highest identity was with French isolates from tomato (FR692835) and lettuce (FR692831). To our knowledge, this is the first report on the occurrence of TSWV in Montenegro. Data of this study sheds light on the importance of further survey studies and inspections of TSWV-susceptible crops cultivated in Montenegro. References: (1) Anonymous. OEPP/EPPO Bull. 29:465, 1999. (2) W. P. Qiu et al. Virology 244:186, 1998. (3) M. Tsompana et al. Mol. Ecol. 14:53, 2005.

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First Report of Tomato spotted wilt virus in Blackberry Lily in North America

Plant Disease ◽

10.1094/pdis.2003.87.1.102c ◽

2003 ◽

Vol 87 (1) ◽

pp. 102-102 ◽

Cited By ~ 3

Author(s):

S. Adkins ◽

L. Breman ◽

C. A. Baker ◽

S. Wilson

Keyword(s):

North America ◽

Tomato Spotted Wilt Virus ◽

Amino Acid Sequences ◽

South Florida ◽

N Gene ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

First Report ◽

Tomato Spotted Wilt ◽

Wilt Virus

Blackberry lily (Belamcanda chinensis (L.) DC.) is an herbaceous perennial in the Iridaceae characterized by purple-spotted orange flowers followed by persistent clusters of black fruit. In July 2002, virus-like symptoms including chlorotic ringspots and ring patterns were observed on blackberry lily leaves on 2 of 10 plants in a south Florida ornamental demonstration garden. Inclusion body morphology suggested the presence of a Tospovirus. Tomato spotted wilt virus (TSWV) was specifically identified by serological testing using enzyme-linked immunosorbent assay (Agdia, Elkhart, IN). Sequence analysis of a nucleocapsid (N) protein gene fragment amplified by reverse transcription-polymerase chain reaction (RT-PCR) with primers TSWV723 and TSWV722 (1) from total RNA confirmed the diagnosis. Nucleotide and deduced amino acid sequences of a 579 base pair region of the RT-PCR product were 95 to 99% and 95 to 100% identical, respectively, to TSWV N-gene sequences in GenBank. Since these 2-year-old plants were grown on-site from seed, they were likely inoculated by thrips from a nearby source. Together with a previous observation of TSWV in north Florida nursery stock (L. Breman, unpublished), this represents, to our knowledge, the first report of TSWV infection of blackberry lily in North America although TSWV was observed in plants of this species in Japan 25 years ago (2). References: (1) S. Adkins, and E. N. Rosskopf. Plant Dis. 86:1310, 2002. (2) T. Yamamoto and K.-I. Ohata. Bull. Shikoku Agric. Exp. Stn. 30:39, 1977.

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Tomato spotted wilt virus Identified in Desert Rose in Florida

Plant Disease ◽

10.1094/pd-89-0526c ◽

2005 ◽

Vol 89 (5) ◽

pp. 526-526 ◽

Cited By ~ 5

Author(s):

S. Adkins ◽

C. A. Baker

Keyword(s):

Tomato Spotted Wilt Virus ◽

The United States ◽

N Gene ◽

Enzyme Linked Immunosorbent Assay ◽

Insect Vector ◽

Rt Pcr ◽

Tomato Spotted Wilt ◽

Wilt Virus ◽

Symptomatic Plant ◽

Das Elisa

Desert rose (Adenium obesum (Forssk.) Roem. & Schult), a member of the family Apocynaceae, is characterized by fleshy stems and leaves and colorful flowers. This exotic ornamental, originally from southeast Africa, is propagated vegetatively and is a perennial in warm climates. Virus-like foliar symptoms, including chlorotic ring and line patterns, were observed in the fall of 2004 on one of five stock plants being maintained in a greenhouse in Fort Pierce, FL. Inclusion body morphology suggested the presence of a Tospovirus in the symptomatic plant, and Tomato spotted wilt virus (TSWV) was specifically identified in this plant using a commercially available double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA; Agdia, Elkhart, IN). TSWV was not detected in symptomless desert rose plants nor was Impatiens necrotic spot virus detected in any of the plants using DAS-ELISA. Graft transmission of TSWV to other desert rose plants was successful. Sequence analysis of a nucleocapsid (N) protein gene fragment amplified by reverse transcription-polymerase chain reaction (RT-PCR) with primers TSWV723 and TSWV722 (1) from total RNA of the symptomatic plant confirmed the diagnosis. Nucleotide and deduced amino acid sequences of a 579-bp region of the RT-PCR product were 95 to 99% and 95 to 100% identical, respectively, to TSWV N-gene sequences in GenBank. No product was amplified from symptomless plants. Since these 3-year-old plants were grown on-site from seed and only expressed symptoms 2 months following damage to the greenhouse by hurricanes Frances and Jeanne, it is likely that viruliferous thrips were introduced from local vegetable or ornamental production areas during or following the storms. To our knowledge, this is the first report of TSWV infection of desert rose in Florida, although TSWV was observed in this plant in Europe approximately 10 years ago (3,4). Because of the wide distribution of TSWV in the United States, the increasing popularity of desert rose, and the recent identification of Cucumber mosaic virus in this host (2), attention to sanitation and insect vector management is merited during desert rose propagation and production. References: (1) S. Adkins and E. N. Rosskopf. Plant Dis. 86:1310, 2002. (2) C. A. Baker et al. Plant Dis. 87:1007, 2003. (3) J. Mertelik et al. Acta Hortic. 432:368, 1996. (4) J. Th. J. Verhoeven and J. W. Roenhorst. Acta Hortic. 377:175, 1994.

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The First Report of Tomato spotted wilt virus on Gerbera and Chrysanthemun in Venezuela

Plant Disease ◽

10.1094/pdis-01-14-0007-pdn ◽

2014 ◽

Vol 98 (8) ◽

pp. 1161-1161 ◽

Cited By ~ 8

Author(s):

E. Marys ◽

A. Mejías ◽

E. Rodríguez-Román ◽

D. Avilán ◽

T. Hurtado ◽

...

Keyword(s):

Tomato Spotted Wilt Virus ◽

Disease Incidence ◽

The United States ◽

Cut Flowers ◽

Rt Pcr ◽

Tomato Spotted Wilt ◽

Arachis Hypogaea L ◽

Pcr Products ◽

Ornamental Crops ◽

Wilt Virus

Gerbera (Gerbera jamesonii) and Chrysanthemum (family Asteraceae) are two of the top 10 cut flowers of the world, with great commercial value. Since 1998, Venezuela began a floral industry to produce and export fresh cut gerbera and chrysanthemum, with 40% of nurseries concentrated in Altos Mirandinos (Miranda State, north central region of the country). For the past 2 years, greenhouse-grown gerbera and chrysanthemum have been observed displaying symptoms resembling those associated with tospoviruses. Symptomatic plants showed concentric rings, irregular chlorotic blotches, and deformation on leaves. Disease incidence was estimated at 30%. Mechanical inoculation with extracts of symptomatic leaves reproduced the typical concentric ring symptoms on indicator plants Arachis hypogaea L. cv. San Martín, Capsicum chinense, and G. jamesonii 6 to 15 days after inoculation. In initial tests, leaves from each 30 symptomatic gerbera and chrysanthemum species from several greenhouse facilities in Altos Mirandinos reacted positively when tested by DAS-ELISA with polyclonal antisera (ATCC, Rockville, MD) raised against Tomato spotted wilt virus (TSWV). Total RNA was extracted with the RNeasy Plant Mini kit (QIAGEN, Hilden, Germany) from two gerbera and two chrysanthemum ELISA-positive samples. The TSWV coat protein gene was amplified by conventional reverse transcription (RT)-PCR using primers CP1 TSWV (TTAACTTACAGCTGCTTT) and CP2 TSWV (CAAAGCATATAAGAACTT) (1). A single DNA product of ~823 bp was amplified from all samples. RT-PCR products were directly sequenced in both orientations and sequences were deposited in GenBank (Accession Nos. KF146700 and KF146701 derived from chrysanthemum, KF146702 and KF146703 derived from gerbera). The resulting sequences showed over 99% identity with each other. and were found to be closely related (over 99%) with TSWV isolates deposited in GenBank originating from different hosts from France (FR693058, FR693055), Montenegro (GU339506, GU339508, GU355940), Italy (HQ830187), New Zealand (KC494501), South Korea (KC261967), and the United States (AY744476). To our knowledge, this is the first confirmed report of TSWV infecting gerbera and chrysanthemum in Venezuela. The relatively widespread occurrence of TSWV in Miranda State underscores the need for systematic surveys to assess its incidence and impact on ornamental crops so that appropriate management tactics can be developed. Reference: (1) R. A. Mumford et al. J. Virol. Methods 57:109, 1996.

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Outbreak of Tomato spotted wilt virus in Tomato in Kenya

Plant Disease ◽

10.1094/pdis.2001.85.10.1123b ◽

2001 ◽

Vol 85 (10) ◽

pp. 1123-1123 ◽

Cited By ~ 6

Author(s):

A. W. Wangai ◽

B. Mandal ◽

H. R. Pappu ◽

S. Kilonzo

Keyword(s):

Host Range ◽

Tomato Spotted Wilt Virus ◽

Virus Disease ◽

N Gene ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

Tomato Spotted Wilt ◽

Wide Host Range ◽

Test Kit ◽

Wilt Virus

Tomato spotted wilt virus (TSWV) of the genus Tospovirus, family Bunyaviridae (1), causes an economically important virus disease in tomato in several parts of the world. The virus has a wide host range that includes numerous crops and weeds and is transmitted by at least seven species of thrips. Tomato crops in the Subukia, Bahati, and Kabazi areas of the Nakuru District in Kenya were affected by a disease suggestive of TSWV infection during the November 1999 to March 2000 tomato-growing season. Farmers reported up to 80% losses of their potential yields. Characteristic symptoms were noticed on fruits, especially when they were green. Distinct concentric rings on fruits, which later turned into brown, uneven ripening, were the most visible symptoms. Foliage did not develop pronounced symptoms, but mild bronzing was observed in a few cultivars. However, foliage senesced prematurely, starting with older leaves. Foliar symptoms were mistaken for blight infection, and as a result, excessive fungicides were applied that failed to manage the disease. To test for TSWV infection, tomato leaf samples collected from the fields were tested initially with a TSWV test kit (HortiTech, Horticulture Research International, Wellesbourne, UK), and the results were confirmed by double-antibody sandwich-enzyme-linked immunosorbent assay with antibodies from Agdia Inc. (Elkhart, IN). Further molecular characterization was done using reverse transcription-polymerase chain reaction (RT-PCR). Total RNA was extracted from symptomatic leaves of tomato cv. Money Maker using the RNeasy mini kit (Qiagen Inc., Valencia, CA). Using primers 5′ TTAAGC AAGTTCTGTGAG 3′ and 5′ ATGTCTAAGGTTAAGCTC 3′ specific to the nucleoprotein (N) gene of TSWV, the N gene was amplified by RT-PCR (2). A 777-bp product of the expected size was obtained from symptomatic plants, whereas no amplification was obtained from noninfected tomato. The PCR product was cloned into pGEM-T Easy (Promega, Madison, WI) and sequenced. A search of GenBank revealed a sequence identity of 95 to 99% with the N genes of known TSWV isolates. To our knowledge, this is the first report TSWV infection of tomato in Kenya. Considering its wide host range, future surveys should be directed toward estimating its incidence in tomato and other TSWV-susceptible crops, such as Irish potatoes, pepper, peanut (groundnut), beans, and a wide variety of ornamental cut flowers in Kenya. References: (1) J. W. Moyer. Tospoviruses (Bunyaviridae). Pages 1803–1807 in: Encyclopedia of Virology. A. Granoff and R. G. Webster, eds. Academic Press, San Diego, CA, 1999. (2) Jain et al. Plant Dis. 82:900, 1998.

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First Report of Vidalia Onion (Allium cepa) Naturally Infected with Tomato spotted wilt virus and Iris yellow spot virus (Family Bunyaviridae, Genus Tospovirus) in Georgia

Plant Disease ◽

10.1094/pdis.2004.88.11.1285b ◽

2004 ◽

Vol 88 (11) ◽

pp. 1285-1285 ◽

Cited By ~ 19

Author(s):

S. W. Mullis ◽

D. B. Langston ◽

R. D. Gitaitis ◽

J. L. Sherwood ◽

A. C. Csinos ◽

...

Keyword(s):

Tomato Spotted Wilt Virus ◽

Thrips Tabaci ◽

Iris Yellow Spot Virus ◽

Yellow Spot ◽

Unknown Etiology ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

Spot Virus ◽

Tomato Spotted Wilt ◽

Wilt Virus

Vidalia onion is an important crop in Georgia's agriculture with worldwide recognition as a specialty vegetable. Vidalia onions are shortday, Granex-type sweet onions grown within a specific area of southeastern Georgia. Tomato spotted wilt virus (TSWV) has been endemic to Georgia crops for the past decade, but has gone undetected in Vidalia onions. Tobacco thrips (Frankliniella fusca) and Western flower thrips (Frankliniella occidentalis) are the primary vectors for TSWV in this region, and a number of plant species serve as reproductive reservoirs for the vector or virus. Iris yellow spot virus (IYSV), an emerging tospovirus that is potentially a devastating pathogen of onion, has been reported in many locations in the western United States (2,4). Thrips tabaci is the known vector for IYSV, but it is unknown if noncrop plants play a role in its epidemiology in Georgia. During October 2003, a small (n = 12) sampling of onions with chlorosis and dieback of unknown etiology from the Vidalia region was screened for a variety of viruses, and TSWV and IYSV infections were serologically detected. Since that time, leaf and bulb tissues from 4,424 onion samples were screened for TSWV and IYSV using double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA) with commercial kits (Agdia Inc., Elkhart, IN). Samples were collected from 53 locations in the Vidalia region during the growing season between November 2003 and March 2004. Plants exhibiting stress, such as tip dieback, necrotic lesions, chlorosis or environmental damage were selected. Of these, 306 were positive for TSWV and 396 were positive for IYSV using positive threshold absorbance of three times the average plus two standard deviations of healthy negative onion controls. Positive serological findings of the onion tissues were verified by immunocapture-reverse transcription-polymerase chain reaction (IC-RT-PCR) for TSWV (3) and RT-PCR for IYSV (1). In both instances, a region of the viral nucleocapsid (N) gene was amplified. The PCR products were analyzed with gel electrophoresis with an ethidium bromide stain in 0.8% agarose. Eighty-six percent (n = 263) of the TSWV ELISA-positive samples exhibited the expected 774-bp product and 55 percent (n = 217) of the IYSV ELISA-positive samples exhibited the expected 962-bp product. The reduced success of the IYSV verification could be attributed to the age and deteriorated condition of the samples at the time of amplification. Thrips tabaci were obtained from onion seedbeds and cull piles within the early sampling (n = 84) and screened for TSWV by the use of an indirect-ELISA to the nonstructural (NSs) protein of TSWV. Of the thrips sampled, 25 were positive in ELISA. While the incidence of IYSV and TSWV in the Vidalia onion crop has been documented, more research is needed to illuminate their potential danger to Vidalia onions. References: (1) I. Cortês et al. Phytopathology 88:1276, 1998. (2) L. J. du Toit et al. Plant Dis. 88:222, 2004. (3) R. K. Jain et al. Plant Dis. 82:900, 1998. (4) J. W. Moyer et al. (Abstr.) Phytopathology 93(suppl.):S115, 2003.

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Development of Reverse Transcription Thermostable Helicase-Dependent DNA Amplification for the Detection of Tomato Spotted Wilt Virus

Journal of AOAC International ◽

10.5740/jaoacint.16-0132 ◽

2016 ◽

Vol 99 (6) ◽

pp. 1596-1599 ◽

Cited By ~ 4

Author(s):

Xinghai Wu ◽

Chanfa Chen ◽

Xizhi Xiao ◽

Ming Jun Deng

Keyword(s):

Reverse Transcriptase ◽

Mosaic Virus ◽

Reverse Transcription ◽

Tomato Spotted Wilt Virus ◽

Tomato Mosaic Virus ◽

N Gene ◽

Impatiens Necrotic Spot Virus ◽

Rt Pcr ◽

Tomato Spotted Wilt ◽

Wilt Virus

Abstract A protocol for the reverse transcription-helicase-dependent amplification (RT–HDA) of isothermal DNA was developed for the detection of tomato spotted wilt virus (TSWV). Specific primers, which were based on the highly conserved region of the N gene sequence in TSWV, were used for the amplification of virus's RNA. The LOD of RT–HDA, reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP), and reverse transcriptase-polymerase chain reaction (RT-PCR) assays were conducted using 10-fold serial dilution of RNA eluates. TSWV sensitivity in RT–HDA and RT-LAMP was 4 pg RNA compared with 40 pg RNA in RT-PCR. The specificity of RT–HDA for TSWV was high, showing no cross-reactivity with other tomato and Tospovirus viruses including cucumber mosaic virus (CMV), tomato black ring virus (TBRV), tomato mosaic virus (ToMV), or impatiens necrotic spot virus (INSV). The RT–HDA method is effective for the detection of TSWV in plant samples and is a potential tool for early and rapid detection of TSWV.

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