scholarly journals Outbreak of Tomato spotted wilt virus in Tomato in Kenya

Plant Disease ◽  
2001 ◽  
Vol 85 (10) ◽  
pp. 1123-1123 ◽  
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.

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

Plant Disease ◽  
2003 ◽  
Vol 87 (1) ◽  
pp. 102-102 ◽  
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.

scholarly journals Tomato spotted wilt virus Identified in Desert Rose in Florida

Plant Disease ◽  
2005 ◽  
Vol 89 (5) ◽  
pp. 526-526 ◽  
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.

Comparison of ELISA and RT-PCR assays for the detection of Tomato spotted wilt virus in peanut

2009 ◽  
Vol 36 (2) ◽  
pp. 133-137 ◽  
Author(s):  
P. M. Dang ◽  
D. L. Rowland ◽  
W. H. Faircloth
Keyword(s):  
Tomato Spotted Wilt Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Infection Rates ◽  
Rt Pcr ◽  
Chi Square ◽  
Tomato Spotted Wilt ◽  
Significant Difference ◽  
Pcr Assays ◽  
Chi Square Analysis ◽  
Wilt Virus

Abstract Diagnosis of Tomato spotted wilt virus (TSWV) in peanut can be accomplished by enzyme-linked immunosorbent assay (ELISA) or reverse transcription polymerase chain reaction (RT-PCR) but there has been no report of a direct comparison of the success of the two assays in evaluating infection rates of field-grown peanut. We collected peanut root samples from field-grown plants, 76 in 2006 and 48 in 2007, and tested these samples by both ELISA and RT-PCR assays for the presence of TSWV. Out of 124 samples, 50 (40.3%) and 57 (46.0%) were positive for TSWV by ELISA and RT-PCR respectively. In 13.7% of these samples, ELISA and RT-PCR differed in their results. However, Chi square analysis showed no significant difference between the results for these two assays. This result supports the conclusion that ELISA and RT-PCR are comparable for detecting TSWV infection rates in field-grown peanuts.

scholarly journals First Report of Tomato spotted wilt virus on Chrysanthemum in Serbia

Plant Disease ◽  
2013 ◽  
Vol 97 (1) ◽  
pp. 150-150 ◽  
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.

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

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 850-850 ◽  
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.

scholarly journals 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 ◽  
2004 ◽  
Vol 88 (11) ◽  
pp. 1285-1285 ◽  
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.

scholarly journals Evaluation of peanut genotypes for resistance to Tomato spotted wilt virus by mechanical and thrips inoculation

2006 ◽  
Vol 41 (6) ◽  
pp. 937-942 ◽  
Author(s):  
Luciana Cordeiro do Nascimento ◽  
Viboon Pensuk ◽  
Nivânia Pereira da Costa ◽  
Francisco Miguel de Assis Filho ◽  
Gilvan Pio-Ribeiro ◽  
...  
Keyword(s):  
Tomato Spotted Wilt Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mechanical Inoculation ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Breeding Lines ◽  
Tomato Spotted Wilt ◽  
Ic 10 ◽  
Polymerase Chain ◽  
Wilt Virus

The objective of this work was to evaluate the reactions of three peanut breeding lines (IC-10, IC-34, and ICGV 86388) to Tomato spotted wilt virus (TSWV) by mechanical and thrips inoculation, under greenhouse conditions, and compare them to the reactions of cultivars SunOleic, Georgia Green, and the breeding line C11-2-39. TSWV infection by mechanical inoculation was visually assessed using an index ranging from 0 (no symptoms) to 4 (apical death). Enzyme-linked immunosorbent assay was used to confirm TSWV infection from both mechanical and thrips inoculations. IC-10, IC-34, ICGV 86388, and C11-2-39 were more resistant than the cultivars SunOleic and Georgia Green based on mechanical inoculation. Upon thrips inoculation only IC-34 and ICGV-86388 were infected by TSWV, as demonstrated by reverse transcription polymerase chain reaction (RT-PCR), although no symptoms of infection were observed. The peanut breeding lines IC-10, IC-34, and ICGV 86388 show higher level of resistance to TSWV than cultivar Georgia Green considered a standard for TSWV resistance.

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

2016 ◽  
Vol 99 (6) ◽  
pp. 1596-1599 ◽  
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.

scholarly journals First Report of Oidium sp. Powdery Mildew and Tomato spotted wilt virus on Melampodium divaricatum

Plant Disease ◽  
2000 ◽  
Vol 84 (10) ◽  
pp. 1152-1152 ◽  
Author(s):  
G. E. Holcomb ◽  
R. A. Valverde
Keyword(s):  
Powdery Mildew ◽  
Tomato Spotted Wilt Virus ◽  
Virus Disease ◽  
Impatiens Necrotic Spot Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
First Report ◽  
Tomato Spotted Wilt ◽  
Leaf Surfaces ◽  
The Family ◽  
Wilt Virus

Melampodium divaricatum (Rich. ex Pers.) DC. (=M. paludosum H.B.K.), a member of the family Asteraceae and native to South America, is a recent introduction for use as a summer bedding ornamental. In September 1999, melampodium plants in multiple Baton Rouge landscapes were observed with signs of powdery mildew and symptoms of a virus-like disease. Powdery mildew spread throughout one of the plantings by late November and infected flowers and leaves. An Oidium species sporulated on both leaf surfaces but was more common on the adaxial surface. Ellipsoid conidia were produced in chains, lacked fibrosin bodies, and averaged 31 × 19 µm. No sexual stage was observed. Eight of 63 plants (cv. Derby) in one of the plantings showed virus disease symptoms that included severe leaf mosaic, leaf malformation, and stunting. Leaves from infected plants were used to sap inoculate seedling plants of melampodium and Nicotiana benthamiana. Melampodium seedlings developed typical mosaic symptoms after 48 to 56 days. N. benthamiana developed severe chlorosis and mosaic, then wilted and died after 14 days. Noninoculated plants of both species remained healthy. The virus in both plant species was identified as Tomato spotted wilt virus (TSWV) by enzyme-linked immunosorbent assay (ELISA) (Agdia, Elkhart, IN). ELISA tests for presence of Impatiens necrotic spot virus were negative. This is the first report of powdery mildew and TSWV on M. divaricatum.

scholarly journals First Report of Tomato spotted wilt virus on Coprosma repens (Mirror Bush) in Italy

Plant Disease ◽  
2007 ◽  
Vol 91 (10) ◽  
pp. 1362-1362 ◽  
Author(s):  
G. Polizzi ◽  
M. G. Bellardi
Keyword(s):  
Tomato Spotted Wilt Virus ◽  
Protein A ◽  
Culture Collection ◽  
N Gene ◽  
Impatiens Necrotic Spot Virus ◽  
Rt Pcr ◽  
Gardenia Jasminoides ◽  
Tomato Spotted Wilt ◽  
Thermal Cycler ◽  
Wilt Virus

Coprosma repens A. Rich. (mirror bush, Rubiaceae) is a hardy salt tolerant shrub that is native to New Zealand where it is primarily a coastal weed. In temperate climates, many variegated varieties and hybrids of mirror bush grow extensively in gardens. In February 2007, irregular or semicircular necrotic spots, sometimes in concentric rings, were noticed on leaves of approximately 2,000 potted, 1-year-old plants of C. repens ‘Tapuata Gold’ obtained as cuttings from a nursery located in Catania Province. The symptoms were detected on approximately 60% of the plants and were localized exclusively on older leaves especially in the yellow or white border. Protein A sandwich (PAS)-ELISA showed mirror bush was positive for the Batavian lettuce strain of Tomato spotted wilt virus (antiserum to TSWV: PVAS-450 from American Type Culture Collection, Manassas, VA). Double antibody sandwich (DAS)-ELISA with polyclonal antisera to Cucumber mosaic virus, TSWV, and Impatiens necrotic spot virus confirmed the presence of only TSWV. Reverse transcription (RT)-PCR was employed to characterize the TSWV isolate. RT-PCR was carried out with primers (forward 5′-TTA ACT TAC AGC TGC TTT-3′ and reverse 5′-CAA AGC ATA TAA GAA CTT-3′) specific for the CP gene of TSWV (3). Amplification was performed in a thermal cycler (Gene Amp PCR System 24000; Perkin Elmer, Hayward, CA) by preheating at 94°C for 5 min followed by 30 cycles of 1.5 min of denaturation at 94°C, 2 min of annealing at 48°C, and 1 min for extension at 72°C. Finally, the amplified DNA was incubated at 72°C for 7 min for a final extension. All samples yielded DNA fragments of the expected size of 823 bp, which included the entire N gene. Purified PCR products were cloned and sequencing (GenBank Accession No. EU020104) was done by Sequiserve (Vatterstetten, Germany). Comparison with sequences available from the GenBank database showed 96 to 99% homology with the same region of the genome for all TSWV isolates, thus confirming the identity of the virus as an isolate of TSWV. In the Rubiaceae family, TSWV was previously detected on Galium spp., Ixora spp., Gardenia jasminoides Ellis, and Bouvardia sp. (1,2,4). To our knowledge, this is the first occurrence of this virus on a member of the genus Coprosma. The high incidence of the disease in the nursery could be due to propagation of cuttings from an infected source. References: (1) M. K. Hausbeck et al. Plant Dis. 76:795, 1992. (2) C. Jordá et al. Plant Dis. 79:358, 1995. (3) R. A. Mumford et al. J. Virol. Methods 46:303, 1994. (4) A. M. Vaira et al. Plant Pathol. 42:530,1993.

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