scholarly journals First Report of Tomato spotted wilt virus Infection of Tomatillo in Georgia

Plant Disease ◽  
2000 ◽  
Vol 84 (10) ◽  
pp. 1155-1155 ◽  
Author(s):  
J. C. Díaz-Pérez ◽  
H. R. Pappu

During the 2000 spring season, tomatillo (Physalis ixocarpa) plants showing chlorotic streaks on leaves were observed in an experimental plot of the University of Georgia's Coastal Plain Experiment Station in Tift County, GA. Leaf samples from 192 plants were collected. These included plants that had chlorotic streaks and those without obvious symptoms. Samples were tested by ELISA using a commercially available Tomato spotted wilt virus (TSWV) detection kit (Agdia Inc., Elkhart, IN). TSWV was found in 10 samples that had chlorotic streaks on leaves, and the remaining plants with no obvious symptoms were negative for TSWV. Infected plants were found in both cultivars, Verde Puebla and Toma Verde. The presence of the virus had no apparent effect on plant size or fruit appearance. TSWV infection of the ELISA-positive samples was further verified by immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) (1). The primer pair (5′-ATGTCTAAGGTTAAGCTC-3′ and 5′ TTAAGCAAGTTCTGTGAG-3′) represented the first and last 18 bases of the coding region of the nucleocapsid gene of TSWV, respectively, and produced approximately 800-bp PCR product (1). IC-RT-PCR gave a single DNA band of expected size and no amplification was found in the uninfected control. This is the first report of TSWV on tomatillo in Georgia. Reference: (1) R. K. Jain et al. Plant Dis. 82:900, 1998.

Plant Disease ◽  
2000 ◽  
Vol 84 (10) ◽  
pp. 1154-1154 ◽  
Author(s):  
M. T. Momol ◽  
H. R. Pappu ◽  
W. Dankers ◽  
J. R. Rich ◽  
S. M. Olson

In spring 2000, symptoms similar to thrips-vectored spotted wilt disease caused by Tomato spotted wilt virus (TSWV) were observed on habanero (Capsicum chinense) and tabasco (Capsicum frutescens) peppers in north Florida. Habanero peppers were from commercial fields grown for specialty markets and tabasco peppers were from research plots. Symptoms observed were leaf necrosis, fruit drop, necrotic stem lesions, and stunting. Fruit symptoms included chlorotic and necrotic spotting and distinct ring pattern and distortion. The incidence of symptomatic habanero peppers was 7 to 8% in one of the three production fields visited, and a lower incidence in two other fields (all in Jackson County). In tabasco pepper, TSWV was detected in spring and fall 1999, and spring 2000 seasons in 10 to 15% of the plants (Gadsden County). Adjacent tomato fields contained scattered plants exhibiting symptoms of TSWV. Diagnosis of TSWV from symptomatic stems, leaves, and fruit of habanero and tabasco peppers was confirmed by a double antibody sandwich enzyme linked immunosorbent assay (ELISA) using a commercially available kit (Agdia Inc., Elkhart, IN). ELISA values ranged from 1.57 to 1.95 for habanero pepper and 0.80 to 0.95 for tabasco pepper. The mean ELISA value of the negative controls was 0.001. To further verify TSWV infection, immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) was performed (1). The primer pair 5′-ATGTCTAAGGTTAAGCTC-3′ and 5′-TTAAGCAAGTTCTGTGAG-3′ represented the first and last 18 bases of the coding region of the nucleocapsid gene of TSWV, respectively, and produces approximately 800 bp PCR product (1). IC-RT-PCR gave a single DNA band of expected size in both habanero and tabasco samples, while no amplification was found in an uninfected pepper sample. This is the first report of TSWV on habanero and tabasco peppers in Florida. TSWV continues to be an economically important disease constraint to the production of tomato, pepper (C. annuum), peanut, and tobacco in the southeastern United States (observations from Georgia and Florida). Meanwhile, the known host range is expanding to include new species of cultivated vegetables. References: (1) R. K. Jain et al.. Plant Dis. 82:900, 1998.


Plant Disease ◽  
2009 ◽  
Vol 93 (2) ◽  
pp. 202-202 ◽  
Author(s):  
N. A. Barkley ◽  
D. L. Pinnow ◽  
M. L. Wang ◽  
G. A. Pederson

Tomato spotted wilt virus (TSWV; family Bunyaviridae, genus Tospovirus), which is vectored by several species of thrips (order Thysanoptera, family Thripidae), causes a destructive disease that affects many economically important host plants such as tomatoes, peppers, and peanuts. Controlling the spread of this disease is challenging, and currently, only limited strategies are available to prevent and/or control its dissemination, including early diagnosis, destruction of infected material, and elimination of the vector. TSWV has been previously reported in subterranean clover (Trifolium subterraneum), white clover (T. repens), and various unidentified wild clovers (Trifolium spp.) in North America and Australia (1,3), but never before in an African species. T. tembense (Fresen.), an herbaceous annual African clover that is mainly used for grazing, is part of the national germplasm collection housed at the Plant Genetic Resources Conservation Unit in Griffin, GA. TSWV was found naturally infecting several accessions of this species being grown for regeneration in a greenhouse during 2008. Initial putative identification of the virus was done by visual inspection of host symptoms that included ringspots, necrotic and chlorotic local lesions, sometimes mild systemic wilting, and eventually an overall decline of healthy tissue in the infected plants. This was subsequently confirmed by double-antibody sandwich (DAS)-ELISA and reverse transcription (RT)-PCR. Primers (5′-ATGTCTAAGGTTAAGCTC-3′ forward and 5′-TTAAGCAAGTTCTGTGAG-3′ reverse) targeted the nucleocapsid gene of TSWV and amplified an expected product of approximately 800 bp (2). No product was amplified in any of the negative controls. Twenty-six individuals representing twelve plant accessions (PI 517788, 517790, 517792, 517793, 517809, 517832, 517842, 517845, 517851, 517871, 517876, and 517889) were screened for TSWV. Two to three individuals were targeted from each accession. Samples were chosen on the basis of the availability of leaf tissue to perform two diagnostic assays, ELISA and RT-PCR. Samples chosen for this study were all naturally infected by thrips. All but four individuals representing two plant accessions tested positive for the virus. The RT-PCR data substantiated the DAS-ELISA results and confirmed the suspected infection. More than 26% of the positive samples naturally infected by TSWV were further characterized by purifying and sequencing (bidirectionally) the RT-PCR product on an automated CEQ 8000 sequencer (Beckman Coulter, Fullerton, CA). The resulting sequences were aligned and edited using AlignIR (LI-COR, Lincoln, NE). More than 700 bp of sequence data (GenBank Accession No. FJ183743–FJ183746) was compiled and they displayed 98% identity with deposited TSWV nucleocapsid gene sequences in GenBank, with no similarity to any other targets. To our knowledge, this is the first report of TSWV infection in T. tembense. Accessions potentially resistant to TSWV within this species were identified and need to be further substantiated. T. tembense is a wild, native clover in Africa and could serve as a weed host for infection of nearby agronomically important crops. References: (1) I. Bitterlich and L. S. MacDonald. Can. Plant Dis. Surv. 73:137, 1993. (2) R. J. Holguín-Peña and E. O. Rueda-Puente. Plant Dis. 91:1682, 2007. (3) C. R. Wilson. Plant Pathol. 47:171, 1998.


Plant Disease ◽  
2014 ◽  
Vol 98 (9) ◽  
pp. 1283-1283
Author(s):  
S.-K. Choi ◽  
I.-S. Cho ◽  
G.-S. Choi ◽  
J.-Y. Yoon

Brugmansia suaveolens, also known as angel's trumpet, is a semi-woody shrub or a small tree. Because flowers of B. suaveolens are remarkably beautiful and sweetly fragrant, B. suaveolens is grown as ornamentals outdoors year-round in the tropics and subtropics, and as potted plants in temperate regions (1). In February 2013, virus-like symptoms including mosaic symptoms followed by distortion of leaves were observed in a potted B. suaveolens in a nursery in Chung-Nam Province, Korea. Symptomatic leaves were analyzed for the presence of several ornamental viruses including Cucumber mosaic virus (CMV), Tobacco mosaic virus (TMV), Tomato bush stunt virus (TBSV), and Tomato spotted wilt virus (TSWV) by immune-strip diagnostic kits that were developed by our laboratory. Positive controls and extract from healthy leaves of B. suaveolens as a negative control were included in each immune-strip assay. TSWV was detected serologically from the naturally infected B. suaveolens, but CMV, TBSV, and TMV were not detected from the B. suaveolens. The presence of TSWV (named TSWV-AT1) was confirmed by commercially available double-antibody sandwich (DAS)-ELISA kits (Agdia, Elkhart, IN). TSWV-AT1 was mechanically transmitted from the ELISA-positive B. suaveolens to Capsicum annuum and Nicotiana glutinosa, respectively. Inoculated C. annuum showed chlorotic rings in the inoculated leaves and inoculated N. glutinosa produced mosaic and systemic necrosis in the inoculated leaves after 7 days inoculation, respectively, which were consistent with symptoms caused by TSWV (2). To confirm further TSWV-AT1 infection, reverse transcription (RT)-PCR was performed using the One-Step RT-PCR (Invitrogen, Carlsbad, CA) with TSWV-specific primers, TSWV-NCP-For and TSWV-NCP-Rev (3), designed to amplify a 777-bp cDNA of the nucleocapsid protein (NCP) gene. Total RNAs from naturally infected B. suaveolens, symptomatic C. annuum, and N. glutinosa were extracted using RNeasy Plant Mini Kit (Qiagen, Valencia, CA). Total RNAs obtained from a Korean isolate of TSWV (Accession No. JF730744) and healthy B. suaveolens were used as positive and negative controls, respectively. The expected size of the RT-PCR product was amplified from symptomatic B. suaveolens, C. annuum, and N. glutinosa but not from healthy leaves of B. suaveolens. The amplified RT-PCR product from TSWV-AT1 was directly sequenced using BigDye Termination kit (Applied Biosystems, Foster City, CA). Multiple alignment of the TSWV-AT1 NCP sequence (AB910533) with NCP sequences of other TSWV isolates using MEGA5 software (4) revealed 99.0% aa identity with an Korean TSWV isolate (AEB33895) originating from tomato. These results provide additional confirmation of TSWV-AT1 infection. It is known that high-value ornamentals may act also as reservoirs for TSWV that can infect other ornamentals and cultivated crops, because TSWV has a very broad host range (2). Elaborate inspections for TSWV and other viruses are necessary for production of healthy B. suaveolens, since the popularity and economic importance of this ornamental plant is increasing. To our knowledge, this is the first report of TSWV in B. suaveolens in Korea. References: (1) Anonymous. OEPP/EPPO Bull. 34:271, 2004. (2) G. Parrella et al. J. Plant Pathol. 85:227, 2003. (3) B.-N. Chung et al. Plant Pathol. J. 28:87, 2012. (4) K. Tamura et al. Mol. Biol. Evol. 28:2731, 2011.


Plant Disease ◽  
2000 ◽  
Vol 84 (4) ◽  
pp. 491-491 ◽  
Author(s):  
A. Gera ◽  
A. Kritzman ◽  
J. Cohen

In July 1998, Pittosporum tobira shrubs, grown in a nursery in the Sharon Valley of Israel, developed foliar ring spots, mild mosaic, and tip necrosis. Of 15 samples tested for the presence of Tomato spotted wilt virus (TSWV) with a commercially available enzyme-linked immunosorbent assay (ELISA) kit (Loewe Biochemica, Otterfing, Germany), 14 were positive for TSWV. Virus in crude sap extracted from symptomatic tissue was mechanically transmitted to Emilia spp., Petunia hybrida, Nicotiana glutinosa, N. benthamiana, and N. rustica plants, which developed symptoms characteristic of TSWV infection (1). ELISA tests of leaf sap extracted from naturally infected P. tobira and mechanically inoculated indicator plants gave a strong positive reaction to TSWV. Leaf samples of P. tobira were analyzed by transmission electron microscopy in leaf-dip preparations and thin sections of leaf tissues. Virus particles typical of a tospovirus were observed only in samples taken from symptomatic leaves. Primers specific to the nucleocapsid gene of TSWV were used in a reverse transcription-polymerase chain reaction (RT-PCR) assay to verify the presence of TSWV. RT-PCR gave an expected PCR product of ≈850 bp. The amplicon was cloned in the pGEM-T vector, and the recombinant clone was sequenced. The sequence of the cloned PCR product confirmed the identity of TSWV, verifying TSWV infection of P. tobira. This is the first report of infection of P. tobira by TSWV. Reference: (1) Y. Antignus et al. Phytoparasitica 25:319, 1997.


Plant Disease ◽  
2003 ◽  
Vol 87 (1) ◽  
pp. 102-102 ◽  
Author(s):  
S. Adkins ◽  
L. Breman ◽  
C. A. Baker ◽  
S. Wilson

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.


Plant Disease ◽  
2013 ◽  
Vol 97 (1) ◽  
pp. 150-150 ◽  
Author(s):  
I. Stanković ◽  
A. Bulajić ◽  
A. Vučurović ◽  
D. Ristić ◽  
K. Milojević ◽  
...  

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.


Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 524-524 ◽  
Author(s):  
C. Nischwitz ◽  
S. W. Mullis ◽  
R. D. Gitaitis ◽  
A. S. Csinos

Tomato spotted wilt virus (TSWV) is a member of the family Bunyaviridae and has a wide host range including important crops such as tomato, pepper, tobacco, peanut, and onion. In areas of Georgia, soybean (Glycine max) is double cropped between two onion crops and as a rotation crop with peanuts. Soybeans do not show any TSWV symptoms, and therefore, have not been tested on a large scale for the virus. However, because symptomless weed and crop plants provide a reservoir for TSWV and the thrips vectors (2), a survey was conducted during the summer of 2005 to evaluate the occurrence of TSWV in soybean. The survey took place in seven counties in southern Georgia with field sizes ranging between 0.4 and 20 ha (1 and 50 acres). Soybean cultivars included Haskell, DP7220, DP6770, Pioneer 97B52, and Vigoro V622NRR. Of 848 randomly selected plants tested using the double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) (Agdia, Inc., Elkhart, IN), 6.6% tested positive for TSWV. Plants testing positive ranged from seedling to the pod-setting stages. Leaves and roots of several plants tested positive, indicating a systemic infection. Soybean plants testing positive using ELISA were blotted onto FTA cards (Whatman Inc., Brentford, UK) to bind viral RNA for preservation, and the blotted samples were processed according to the manufacturer's protocol. Reverse transcription-polymerase chain reaction using punch-outs from the FTA cards and TSWV nucleocapsid gene specific forward and reverse primers (5′-TTAAGCAAGTTCTGTGAG-3′ and 5′-ATGTCTAAGGTTAAGCTC-3′), respectively (4), confirmed the identity of TSWV. TSWV has been found in soybean in other parts of the world (1) but has only been reported in the United States in a survey from Tennessee (3). To our knowledge, this is the first report of the occurrence of TSWV in soybean in Georgia. The role soybean plays as a reservoir or green bridge for thrips and TSWV is currently unknown. References: (1) A. R. Golnaraghi et al. Plant Dis. 88:1069, 2004. (2) R. L. Groves et al. Phytopathology 91:891, 2001. (3) B. S. Kennedy and B. B. Reddick. Soybean Genet. Newsl. 22:197, 1995. (4) H. R. Pappu et al. Tob. Sci. 40:74, 1996.


Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 525-525 ◽  
Author(s):  
C. Nischwitz ◽  
S. W. Mullis ◽  
R. D. Gitaitis ◽  
A. S. Csinos ◽  
S. M. Olson

Tomato spotted wilt virus (TSWV) is a member of the family Bunyaviridae. It has many important crop hosts including tomato, pepper, tobacco, peanut, and onion. In Georgia, Vidalia onions (Allium cepa), a close relative of leek, can be infected by TSWV and Iris yellow spot virus (IYSV), which is another thrips-vectored tospovirus (2). For this reason, samples of leek transplants with virus-like symptoms in one field at the border of Georgia and Florida were tested for the presence of TSWV and IYSV. The transplants had been grown from seed in a greenhouse at the same location. The sampled plants exhibited extended bleaching of leaf tips and necrotic lesions. These symptoms were also seen on onion plants infected with TSWV and IYSV. The only natural infections of leek with IYSV have been reported thus far only from Reunion Island (4) and Slovenia (1), but to our knowledge, TSWV has not been reported as a pathogen of leek. Green tissue near the necrotic lesions and bleached tips of one symptomatic leaf per plant was sampled and analyzed using a double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) (Agdia, Inc., Elkhart, IN). Of 90 plants tested, eight were positive for TSWV and none were positive for IYSV. Leek samples testing positive using ELISA were blotted onto FTA cards (Whatman Inc., Brentford, UK) to bind viral RNA for preservation and then processed according to the manufacturer's protocol. Punch-outs from the FTA cards were used for reverse transcription polymerase chain reaction (RT-PCR) with the TSWV-specific forward primer (5′-TTAAGCAAGTTCTGTGAG-3′) and reverse primer (5′-ATGTCTAAGGTTAAGCTC-3′) (3) to confirm the identity of TSWV. The primers are specific to the viral nucleocapsid gene. An amplicon of the expected size (774 bp) was produced from TSWV ELISA-positive leek plants, but not from healthy controls. TSWV has been found in many plants worldwide, but to our knowledge this is the first report of TSWV infecting leek. The effect that TSWV has on leek production is currently unknown. References: (1) D. A. Benson et al. Nucleic Acids Res. 1:32 (Database issue):D23-6, 2004. (2) S. W. Mullis et al. Plant Dis. 88:1285, 2004. (3) H. R. Pappu et al. Tob. Sci. 40:74, 1996. (4) I. Robène-Soustrade et al. Online publication. New Dis. Rep. 11, 2005.


Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 850-850 ◽  
Author(s):  
D. Nikolić ◽  
I. Stanković ◽  
A. Vučurović ◽  
D. Ristić ◽  
K. Milojević ◽  
...  

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.


Plant Disease ◽  
2014 ◽  
Vol 98 (11) ◽  
pp. 1591-1591 ◽  
Author(s):  
M. A. Al-Saleh ◽  
I. M. Al-Shahwan ◽  
M. A. Amer ◽  
M. T. Shakeel ◽  
M. H. Ahmad ◽  
...  

A survey for viruses in open field lettuce crops was carried out in March 2014 in the Al-Uyaynah area, central region of Saudi Arabia. In one plot, more than 50% of the lettuce plants (Lactuca sativa; hybrid: Romaine), with the majority of the affected plants in the edges of the plot, were showing virus-like symptoms such as necrotic lesions, necrosis of the lamina of the younger leaves, and leaf curling, indicating a possible infection by a Tospovirus, possibly Tomato spotted wilt virus (TSWV). Most of them were dead when the field was visited again 3 weeks later. Samples from 10 symptomatic and two asymptomatic plants were collected. Five of the samples from symptomatic and two from asymptomatic plants were mechanically inoculated onto Nicotiana benthamiana and N. glutinosa (three indicator plants of each species were used for each sample) using 0.1 M phosphate buffer (pH 7) containing 0.01M Na2SO3 mM. All the symptomatic lettuce samples were also tested serologically using polyclonal antisera (3) against TSWV, CMV, and by using monoclonal antibodies against potyviruses. Moreover, total RNA was extracted (1) and detection of TSWV was also attempted with reverse transcription (RT)-PCR using species specific primers (4) for a 276-bp fragment of the L RNA segment. In both serological and molecular methods, positive and negative controls were included. All the mechanically inoculated plants with tissue from the symptomatic lettuce plants of N. benthamiana showed chlorotic local lesions followed by systemic top necrosis 2 to 3 weeks post inoculation. Similarly, all inoculated N. glutinosa plants showed necrotic local lesions followed by systemic chlorosis. However, all the indicator plants mechanically inoculated with tissue from asymptomatic lettuce plants gave no reaction. All the symptomatic lettuce samples reacted positively, while asymptomatic samples reacted negatively in ELISA tests with TSWV antiserum and the presence of the virus was further confirmed by RT-PCR by using specific primers (method A) (4). PCR products of two randomly selected positive samples were directly sequenced and BLAST analysis of the obtained sequences (Accession Nos. KJ701035 and KJ701036) revealed 99% nucleotide and 100% amino acid identity with the deposit sequence in NCBI from South Korea (KC261947). Regarding mechanical inoculation, 10 days post-inoculation, both indicator plants showed typical symptoms of TSWV infection, such as necrotic local lesions, systemic necrotic patterns, and leaf deformation. None of the symptomatic plants was found to be infected with either CMV or potyvirus. To our knowledge, this is the first report of TSWV naturally infecting lettuce in Saudi Arabia; therefore, insect vector and weed management are necessary measures to control the virus spread to other crops such as tomato and pepper (2). References: (1) E. Chatzinasiou et al. J. Virol. Meth. 169:305, 2010. (2) E. K. Chatzivassiliou. Plant Dis. 92:1012, 2008. (3) E. K. Chatzivassiliou et al. Phytoparasitica 28:257, 2000. (4) R. A. Mumford et al. J. Virol. Meth. 46:303, 1994.


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