scholarly journals First Report of an Isolate of Pelargonium zonate spot virus in Commercial Glasshouse Tomato Crops in Southeastern France

Plant Disease ◽  
2002 ◽  
Vol 86 (9) ◽  
pp. 1052-1052 ◽  
Author(s):  
K. Gebre-Selassie ◽  
B. Delecolle ◽  
P. Gognalons ◽  
O. Dufour ◽  
C. Gros ◽  
...  

In summer 2000, symptoms similar to Pelargonium zonate spot virus (PZSV) were observed for the first time on tomato plants in southeastern France. The plants were from commercial glasshouse fresh-market crops. Symptoms observed were chlorotic mottling with bright yellow distinct rings on leaves and curved line patterns on stems. Fruit symptoms included chlorotic and necrotic spotting, marked concentric ring patterns, and distortions. Diagnosis was made from symptomatic leaves and fruits by mechanical inoculation on a set of host plants. Local chlorotic and necrotic lesions were observed on Chenopodium amaranticolor, C. quinoa, Cucumis sativus cv. Marketer, Cucumis melo cv. Vedrantais, Phaseolus vulgaris cv. Pinto, Vicia faba cv. D'Aguadulce, Vigna unguiculata cv. Black Eye, and systemic symptoms were observed on Capsicum annuum cvs. Yolo Wonder, Yolo Y, Florida VR2, and Criollo de Morelos 334, Datura stramonium, Lycopersicon esculentum cvs. Momor and Stevens, L. hirsutum (PI 134417 and PI 247087), Nicotiana benthamiana, N. clevelandii, N. tabacum cv. Xanthi nc, Ocimum basilicum cv. Latino, Petunia hybrida cv. Rose du ciel, and Physalis floridana. No reaction was observed on Pisum sativum cv. Douce Provence, Salvia splendens cv. Etna, or Zinnia elegans cv. Liliput. Symptoms on tomato of PZSV, Parietaria mottle virus (PMoV), and Tomato spotted wilt virus (TSWV) are similar, particularly those elicited in fruits. Therefore, the field samples were checked using double-antibody sandwich enzyme-linked immunosorbent assay against antisera of the type-strain of PZSV and tomato strain of PMoV and their homologous antigenes, which were supplied by D. Gallitelli and P. Roggero respectively, and our antiserum of TSWV. Electron microscopy of negatively stained preparations from leaves of tomato and D. stramonium showed that the sap contained very few paraspheric shaped particles, 26 to 29 nm in diameter. Three isolates collected from two different regions (Vaucluse and Bouches du Rhône) showed a very close serological relationship with the Italian type-strain of PZSV and tested negative against antisera of PMoV and TSWV. The French isolates were biologically different from the type-strain, but were similar to the Spanish strain of PZSV because they infected D. stramonium, N. benthamiana, O. basilicum, and V. unguiculata (2). Moreover, in transverse tissue sections, virions were not observed in the nucleus and tubular structures, unlike the Italian isolates, (1) but were present in the cytoplasm and particularly in the mesophyll cells. There are only a few records of the occurrence and distribution of PZSV in Mediterranean countries. References: (1) M. A Castellano and G. P Martelli. Phytopathol. Mediterr. 20:64, 1981. (2) M. Luis-Arteaga. Plant Dis. 84:807, 2000.

Plant Disease ◽  
2001 ◽  
Vol 85 (12) ◽  
pp. 1292-1292 ◽  
Author(s):  
C. Jordá ◽  
A. Lázaro Pérez ◽  
P. Martínez-Culebras ◽  
P. Abad ◽  
A. Lacasa ◽  
...  

At the beginning of 2000, a damaging disease developed on protected tomato (Lycopersicon esculentum) crops grown in polyethylene greenhouses in different regions of Spain. Production losses were estimated at 15 to 80%. The tomato plants showed a variety of symptoms. The most common symptoms were leaf distortion, chlorosis, and mosaic. Some plants showed a dark green mosaic and bubbling of the leaf surface. Green striations were also observed on the stem and sepals. Most of the diseased plants had discolored fruits. Symptoms decreased as environmental temperature increased. The involvement of Pepino mosaic virus (PepMV) was suspected. To identify the etiological agent, ≈500 symptomatic tomato plants were collected from several locations in Alicante, Murcia, Almeria and the Canary Islands. Flexuous viral particles 510 nm long were observed by transmission electron microscopy, suggesting the presence of a potexvirus in the tissue extracts analyzed. All samples were tested by ELISA (enzyme-linked immunosorbent assay), using polyclonal antibodies to Narcissus mosaic virus (Adgen, Auchincriuve, Scotland), a virus serologically related to PepMV, and two antisera specific to PepMV (Adgen, Scotland and DMSZ, Braunschweig, Germany). PepMV was detected in 35% of the samples. Like PepMV, the virus infected (as confirmed by ELISA) greenhouse-grown Datura stramonium, Nicandra physalodes, Nicotiana benthamiana, N. clevelandii, Solanum tuberosum, and Vigna sinensis and did not infect Capsicum anuum, Cucumis sativus, Chenopodium amaranticolor, C. quinoa, Petunia × hybrida, Phaseolus vulgaris, Physalis floridana, N. glutinosa, N. rustica, or N. tabacum. The virus did infect Gomphrena globosa, which normally is not infected by PepMV. The first report of PepMV was on pepino (Solanum muricatum) in Peru in 1974 (1), but this virus has been recently reported in the Netherlands, England, Germany, and France on protected tomato crops (2). To our knowledge, this is the first report of PepMV in Spain, including the Canary Islands. References: (1) R. A. C. Jones et al. Ann. Appl. Biol. 94:61, 1980. (2) European and Mediterranean Plant Protection Organisation (EPPO). Alert List Viruses. On-line publication/2000/003.


Plant Disease ◽  
2007 ◽  
Vol 91 (1) ◽  
pp. 112-112 ◽  
Author(s):  
C. A. Baker ◽  
S. Adkins

Zamia furfuracea (Zamiaceae) is native of coastal Mexico. It is a popular houseplant and easy to grow outdoors in warm climates. In November 2005, a plant of Z. furfuracea, originally from Texas, was received at the Division of Plant Industry in Gainesville, FL. The plant had numerous chlorotic spots on the leaves that eventually became necrotic. Leaves were ground in phosphate buffer (pH 7.2) with Carborundum and used to inoculate a host range that included Chenopodium amaranticolor, C. quinoa, Gomphrena globosa, Datura stramonium, and Nicotiana benthamiana. Systemic symptoms were seen in C. quinoa (necrotic lesions), G. globosa (stunting), D. stramonium (chlorotic ringspots), and N. benthamiana (wavy line patterns) 1 to 2 weeks after inoculation. C. amaranticolor showed only small necrotic local lesions. In further host range studies, systemic infections of Beta vulgaris, D. metaloides, Lactuca sativa, N. clevelandii, Pisum sativus, Petunia hybrida, Zinnia elegans (symptomless), and Cucumis sativa were observed. However, no infection of Zea mays, Verbena hybrida, Glycine max, Phaseolus vulgaris, Catharanthus roseus, Arachis hypogaea, Trifolium spp., Vigna unguiculata, Vicia faba or Digitalis spp. was detected. Inclusions observed in leaf strips of N. benthamiana and D. stramonium indicated a possible infection of this plant with a nepovirus (1). A 337-bp fragment was amplified from total RNA isolated from an inoculated D. stramonium using reverse transcription-PCR with nepovirus group primers provided by Agdia Inc. (Elkhart, IN). Sequence analysis indicated that the nucleotide (nt) and deduced amino acid (aa) sequences of the fragment were 89 to 91% and 91 to 95% identical, respectively, to sequences of the RNA-dependent RNA polymerase gene for Tobacco ringspot virus (TRSV) contained in GenBank (Accession Nos. U50869 and AJ698718). This region was only 50% (nt) and 38% (aa) identical to Cycas necrotic stunt virus (GenBank Accession No. NC_003791), a nepovirus previously reported to infect cycads (2). The original plant, symptomatic inoculated hosts, and the symptomless zinnia tested positive by double-antibody sandwich-ELISA using commercially available antiserum for TRSV (Agdia, Inc.), further confirming the presence of TRSV. Although the virus infecting Z. furfuracea has a more restricted host range than that reported for TRSV, the serology and gene sequence indicates that this virus is a unique isolate of TRSV. References: (1) J. R. Edwardson and R. G. Christie. University of Florida, Institute of Food and Agricultural Sciences, Bull. 894. 1996. (2) S. S. Han et al. Arch. Virol. 147:2207, 2002.


Plant Disease ◽  
2000 ◽  
Vol 84 (7) ◽  
pp. 807-807 ◽  
Author(s):  
M. Luis-Arteaga ◽  
M. A. Cambra

Tomato (Lycopersicon esculentum Mill.) plants showing severe chlorotic and necrotic ringspots, line patterns on leaves, and concentric chlorotic ringspots on stems and fruits were observed in plastic greenhouse-grown tomato crops cv. Royesta during the spring of 1996 in Zaragoza province, Northeast Spain. Symptoms were similar to those associated with Pelargonium zonate spot virus (PZSV) infection on tomato in Italy (1,2). The causal agent was mechanically transmitted from leaf, fruit, and stem samples to several indicator species. The following host reactions were recorded: chlorotic local lesions on Chenopodium amaranticolor, C. quinoa, Cucumis sativus, and Cucurbita pepo, and systemic reactions, sometimes associated with localized reactions, on Capsicum annuum ‘Doux des Landes’ and ‘Yolo Wonder’, Datura stramonium, Gomphrena globosa, Nicotiana clevelandii, N. glutinosa, N. megalosiphon, N. rustica, N. sylvestris, N. tabacum ‘Paraguay’, ‘Samsun’, and ‘Xanthi nc’, Ocimum basilicum, Petunia hybrida, Physalis floridana, Solanum melongena, and Vigna unguiculata. Symptoms obtained in indicator species were erratic. During the spring of 1999, naturally occurring symptoms appeared again on tomato plants, cultivars Royesta and Bond, growing in greenhouses in the same area. Positive serological reactions with the enzyme-linked immunosorbent assay (ELISA) using a commercial PZSV antiserum (Agdia Inc.), developed against an Italian isolate of PZSV, were obtained with extracts from leaves, stems, and fruits of tomato plants naturally infected (1999) and from systemically infected indicator species mechanically inoculated with sap from tomato samples (1996 and 1999). Serological results were confirmed by molecular hybridization analysis using a PZSV-specific riboprobe (D. Gallitelli, personal communication). Some of the weeds growing around the greenhouses (Capsella bursa-pastoris, Diplotaxis erucoides, Picris echioides, and Sonchus oleraceus) also tested positive for PZSV (A405nm values greater than three times that of healthy plants). However, other weed species such as Anacyclus tomentosus, Beta maritima, Cardaria draba, Malva sylvestris, Medicago sp., Polygonum aviculare, Rumex sp., and Sisymbrium irio tested negative, while results from tests on Borago officinalis, Bromus rigidus, and Convolvulus arvensis were inconclusive. Symptoms like those of naturally infected tomato plants were reproduced by mechanically inoculating tomato seedlings with sap from PZSV-infected tobacco (Nicotiana glutinosa and N. tabacum ‘Paraguay’) or from Physalis floridana plants. References: (1) D. Gallitelli. Ann. Appl. Biol. 100:457, 1982. (2) C. Vovlas et al. Inform. Fitopatol. 2:39, 1986.


Plant Disease ◽  
2000 ◽  
Vol 84 (10) ◽  
pp. 1152-1152 ◽  
Author(s):  
P. Roggero ◽  
G. P. Accotto ◽  
M. Ciuffo ◽  
R. Lenzi ◽  
C. Desbiez ◽  
...  

Tobacco vein banding mosaic virus (TVBMV) has been reported in Taiwan (1), North America (Tennessee) (2), and Japan (3) and induces a severe disease of tobacco. During surveys on viruses of vegetables in China, TVBMV was isolated from a Datura stramonium weed plant in July 1998 in Shaanxi Province. It showed severe mosaic with blistering of the leaves. The plant was also infected by Cucumber mosaic virus (CMV). When sap from D. stramonium was frozen, thawed, and mechanically inoculated, only TVBMV was recovered. The 3′-end of the viral genome was amplified by reverse transcription-polymerase chain reaction (RT-PCR) using primers derived from the potyviridae primers (4) and cloned in pBlueScript. The sequence of 1,630 bp (GenBank AF274315) was determined on both DNA strands and found to have approximately 94% homology with other TVBMV sequences (L 28816 from Tennessee, X77637 from Taiwan, and AB020524 from Japan). The host range of the Chinese isolate was similar to that reported for the U.S. isolate. D. stramonium, Nicotiana benthamiana, N. clevelandii, N. glutinosa, N. tabacum Samsun, White Burley type and Xanthi, Lycopersicon esculentum cv. Marmande, and Petunia hybrida were systemically infected. A local infection developed in N. rustica, Chenopodium amaranticolor, C. quinoa, and Ocimum basilicum. The Chinese isolate did not infect Capsicum annuum cv. Quadrato d'Asti, Solanum melongena, or several Cucurbitaceae and Leguminosae species. Myzus persicae transmitted the Chinese TVBMV in a non-persistent mode from both D. stramonium and tobacco to the same plants and to tomato. No seed transmission occurred in experimentally infected D. stramonium (20 seedlings), tobacco White Burley type (200 seedlings), and tomato cv. Marmande (100 seedlings). The virus was found in the roots of D. stramonium and tobacco. Since the virus was not seed-transmissible, overwintering rootstocks may provide sites for winter survival of the virus. An antiserum was produced against the virus and an enzyme-linked immunosorbent assay survey was carried out in solanaceous crops including D. stramonium collected in July 1999 in Shaanxi, Shanxi, Henan, and Hebei provinces and Beijing surroundings. TVBMV was found only in the same field as in 1998 in four D. stramonium plants in association with CMV and in a tobacco plant 200 m from D. stramonium. TVBMV was not found in the closest tomato crops, where infection of CMV was severe. This is the first report of TVBMV in China, and Xian is the most northern location in which this virus has been found. References: (1) J. K. Chiang et al. Bull. Tobacco Res. Inst. 32:39, 1990. (2) B. B. Reddick et al. Plant Dis. 76:856, 1992. (3) H. Tochihara. Rev. Plant Prot. Res. 13:122, 1980. (4) A. Gibbs and A. Mackenzie. J. Virol. Meth. 63:9, 1997.


Plant Disease ◽  
2002 ◽  
Vol 86 (6) ◽  
pp. 694-694 ◽  
Author(s):  
N. Shahraeen ◽  
T. Ghotbi ◽  
A. H. Mehraban

Impatiens necrotic spot virus (INSV) (genus Tospovirus, family Bunyaviridae) has been detected in commercial nurseries and field-grown ornamentals in Mahallat (Markazi) and Tehran provinces of Iran. INSV on ornamentals was first reported in 1990 (2). Ornamental plants with small necrotic spots, leaf yellowing, ring spots, necrotic vein clearing, wilting, and dwarf symptoms were collected. For mechanical inoculation on selected host species, leaf samples were triturated in chilled 0.01 phosphate buffer, pH 7.2, containing 0.02% sodium sulfite. Cowpea (cv. Mashad local), Chenopodium amaranticolor, Datura mete, Nicotiana rustica, N. tabacum (cv. White Burly), and Lycopersicon sp. produced local necrotic symptoms 5 days postinoculation. N. rustica, N. tabacum cv. White Burley, and D. metel also developed systemic mosaic symptoms that were followed by total wilting and death of the plant. The severity of the disease was higher in warm weather (July and August in greenhouses). Thrips tabaci and Frankliniella intonsa were often present at the site of INSV infection. Triple-antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA) was applied using a commerical polyclonal antibody kit (As-0115) in combination with monoclonal antibody 5E4 (As-0117) prepared against nucleoprotein of INSV isolate Pv-0280 (antibody kits and positive control were a gift from DSMZ, Braunschweig, Germany). Samples were tested for the presence of TSWV and INSV. The ornamental species found infected with INSV were Rosa sp., Gazania sp., Chrysanthemum sp., Leucanthemum sp., Matricaria camomila, Pelargonium roseum, Salvia sp., and Dianthus caryophyllus, which were collected from the Mahallat area; and Gazania sp. and Bougainvillea spectabilis collected from the Tehran Province. ELISA values of field-infected samples (OD405, read after 1h) diluted at 1:10 (wt/vol) were 0.317 (minimum) and 0.914 (maximum), and 0.312 for the positive control. None of the samples reacted in TAS-ELISA with Tomato spotted wilt virus (TSWV) (antibody kits, As-0105, As-0106, and As-01106, gift from DSMZ). A few samples of Chrysanthemum sp. and Leucanthemum sp. (collected from the Mahallat area) reacted in TAS-ELISA with TSWV, indicating they were doubly infected with TSWV and INSV. Within the genus Tospovirus the TSWV peanut isolate has been reported from Iran (1). To our knowledge, this is the first report of the occurrence of INSV on ornamentals in Iran. References: (1) A. R. Golnaraghi et al. Plant Dis. 85:1286, 2001 (2) M. D. Law and J. W. Moyer. J. Gen.Virol.71:933, 1990.


1999 ◽  
Vol 89 (9) ◽  
pp. 823-830 ◽  
Author(s):  
I. C. Bezerra ◽  
R. de O. Resende ◽  
L. Pozzer ◽  
T. Nagata ◽  
R. Kormelink ◽  
...  

During a survey conducted in several different regions of Brazil, two unique tospoviruses were isolated and characterized, one from chrysanthemum and the other from zucchini. The chrysanthemum virus displayed a broad host range, whereas the virus from zucchini was restricted mainly to the family Cucurbitaceae. Double-antibody sandwich-enzyme-linked immunosorbent assay and western immunoblot analyses demonstrated that both viruses were serologically distinct from all reported tospovirus species including the recently proposed peanut yellow spot virus and iris yellow spot virus (IYSV) species. The nucleotide sequences of the nucleocapsid (N) genes of both viruses contain 780 nucleotides encoding for deduced proteins of 260 amino acids. The N proteins of these two viruses displayed amino acid sequence similarities with the previously described tospovirus species ranging from 20 to 75%, but they were more closely related to each other (80%). Based on the biological and molecular features, these viruses are proposed as two new tospovirus species, designated chrysanthemum stem necrosis virus (CSNV) and zucchini lethal chlorosis virus (ZLCV). With the identification of CSNV and ZLCV, in addition to tomato spotted wilt virus, groundnut ring spot virus, tomato chlorotic spot virus, and IYSV, Brazil harbors the broadest spectrum of tospovirus species reported.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Saengsoon Charoenvilaisiri ◽  
Channarong Seepiban ◽  
Mallika Kumpoosiri ◽  
Sombat Rukpratanporn ◽  
Nuchnard Warin ◽  
...  

Abstract Background Cassava mosaic disease (CMD) is one of the most devastating viral diseases for cassava production in Africa and Asia. Accurate yet affordable diagnostics are one of the fundamental tools supporting successful CMD management, especially in developing countries. This study aimed to develop an antibody-based immunoassay for the detection of Sri Lankan cassava mosaic virus (SLCMV), the only cassava mosaic begomovirus currently causing CMD outbreaks in Southeast Asia (SEA). Methods Monoclonal antibodies (MAbs) against the recombinant coat protein of SLCMV were generated using hybridoma technology. MAbs were characterized and used to develop a triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA) for SLCMV detection in cassava leaves and stems. Assay specificity, sensitivity and efficiency for SLCMV detection was investigated and compared to those of a commercial ELISA test kit and PCR, the gold standard. Results A TAS-ELISA for SLCMV detection was successfully developed using the newly established MAb 29B3 and an in-house polyclonal antibody (PAb) against begomoviruses, PAb PK. The assay was able to detect SLCMV in leaves, green bark from cassava stem tips, and young leaf sprouts from stem cuttings of SLCMV-infected cassava plants without cross-reactivity to those derived from healthy cassava controls. Sensitivity comparison using serial dilutions of SLCMV-infected cassava sap extracts revealed that the assay was 256-fold more sensitive than a commercial TAS-ELISA kit and 64-fold less sensitive than PCR using previously published SLCMV-specific primers. In terms of DNA content, our assay demonstrated a limit of detection of 2.21 to 4.08 × 106 virus copies as determined by quantitative real-time PCR (qPCR). When applied to field samples (n = 490), the TAS-ELISA showed high accuracy (99.6%), specificity (100%), and sensitivity (98.2%) relative to the results obtained by the reference PCR. SLCMV infecting chaya (Cnidoscolus aconitifolius) and coral plant (Jatropha multifida) was also reported for the first time in SEA. Conclusions Our findings suggest that the TAS-ELISA for SLCMV detection developed in this study can serve as an attractive tool for efficient, inexpensive and high-throughput detection of SLCMV and can be applied to CMD screening of cassava stem cuttings, large-scale surveillance, and screening for resistance.


1994 ◽  
Vol 6 (2) ◽  
pp. 175-181 ◽  
Author(s):  
A. Lucchelli ◽  
S. Y. Kang ◽  
M. K. Jayasekera ◽  
A. V. Parwani ◽  
D. H. Zeman ◽  
...  

Group A bovine rotaviruses (BRV) have been identified worldwide as a major cause of diarrhea in the young of many species, including humans. Group A rotaviruses are classified into serotypes on the basis of the outer capsid proteins, VP7 (G types) and VP4 (P types). To date, there are 14 G types of group A rotaviruses, with G1, G6, G8, and G10 described for BRV isolates. In this study, G6- and G lo-specific monoclonal antibodies (MAbs) were used in an enzyme-linked immunosorbent assay (ELISA) for the G typing of BRV-positive stool samples from diarrheic beef and dairy calves from South Dakota, Ohio, Michigan, Nebraska, and Washington, USA, and Ontario, Canada. ELISA plates were coated using a broadly reactive VP7 MAb (Common 60) or with G6- or G10-specific MAbs. BRV-positive fecal samples were diluted and added to duplicate wells, followed by the addition of polyclonal guinea pig anti-group A rotavirus serum as the secondary antibody. Several reference G6 and G10 BRV strains as well as other G types previously reported in cattle (G1, G2, G3, G8) and BRV-negative samples were included as G type specificity and negative controls. From a total of 308 field samples analyzed, 79% (244/308) tested positive by the broadly reactive VP7 MAb; of these, 54% (131/244) were G6 positive, 14% (35/244) were G10 positive, 4% (9/244) were both G6 and G10 positive, and 28% (69/244) were G6 and G10 negative. The negative samples may represent additional or undefined serotypes. The 89 samples from South Dakota were further subdivided into samples from beef ( n = 43) or dairy ( n = 46) herds. G6 was more prevalent in beef herd samples (67%) than in dairy herd samples (47.5%). In addition, dairy herds had higher percentages of G10-positive samples (17.5%) G6-G10 double positives (10%), and untypable samples (25%) than did beef herds, in which the prevalence of G10 positive samples was 5.5%, G6-G10 double positives was 5.5%, and untypable samples was 22%. Application of the serotype ELISA for the analysis of additional BRV samples will provide further epidemiologic data on the distribution of BRV serotypes in beef or dairy cattle, an important consideration for the development of improved BRV vaccines.


1998 ◽  
Vol 5 (5) ◽  
pp. 604-608 ◽  
Author(s):  
Deborah Gentile ◽  
William Doyle ◽  
Theresa Whiteside ◽  
Philip Fireman ◽  
Frederick G. Hayden ◽  
...  

ABSTRACT Interleukin-6 (IL-6) is a pleotropic cytokine implicated in the pathogenesis of local inflammation during viral upper respiratory infections. This study determined if experimental influenza A virus infection causes local IL-6 production. Seventeen healthy, adult subjects were intranasally inoculated, by course drops, with a safety-tested strain of influenza A/Kawasaki/86 (H1N1) virus. Nasal lavage samples were collected, symptoms were recorded, and expelled nasal secretions were weighed once before and then daily for 8 days after the virus inoculation. Lavage samples were submitted for virus culture and were examined for IL-6 and IL-4 by enzyme-linked immunosorbent assay. The IL-6, but not IL-4, levels were significantly increased in the nasal lavage samples of the 12 subjects who shed virus but not in those of the 5 subjects who did not shed virus. Moreover, the elevations in IL-6 levels were related temporally to the development of nasal symptoms and secretions but not to systemic symptoms. These results suggest a role for locally produced IL-6 in the pathogenesis and expressed symptomatology of influenza A virus infection.


Plant Disease ◽  
1997 ◽  
Vol 81 (11) ◽  
pp. 1334-1334 ◽  
Author(s):  
R. J. McGovern ◽  
J. E. Polston ◽  
B. K. Harbaugh

In May 1997, inclusions typical of a tospovirus were visualized by light microscopy in leaf tissue of lisianthus (Eustoma grandiflorum) exhibiting stunting, necrotic ringspots, leaf distortion, and systemic necrosis. Wilting and plant death were the final symptoms observed. Affected plants occurred at low incidence (<0.1%) in greenhouse-grown lisianthus in Manatee County, FL. Symptomatic tissue tested positive for impatiens necrotic spot virus (INSV) and negative for tomato spotted wilt virus (TSWV) with enzyme-linked immunosorbent assay (ELISA; Agdia, Elkhart, IN). Mechanical transmission of the virus to lisianthus and tomato was attempted by triturating 1 g of symptomatic leaf tissue in 7 ml of a buffer consisting of 0.01 M Tris and 0.01 M sodium sulfite, pH 7.3. Six plants of lisianthus cv. Maurine Blue and three of tomato (Lycopersicon esculentum) cv. Lanai at the second true-leaf stage were inoculated following abrasion of leaves with Carborundum. An equal number of controls were inoculated with buffer alone. Plants were maintained in a controlled environment chamber with a 12-h photoperiod, day/night temperatures of 21/16°C, and light intensity of 120 μE · s-l · m-2. Transmission rates were 100 and 0% to lisianthus and tomato, respectively. Chlorotic local lesions followed by chlorotic ringspots were observed in inoculated lisianthus leaves 4 days after inoculation. Stunting, leaf distortion, and necrotic ringspots appeared in noninoculated leaves of lisianthus plants within 3 to 4 weeks after inoculation. Buffer-inoculated lisianthus and all tomato plants remained symptomless and tested negative for INSV by ELISA. All symptomatic lisianthus tested positive for INSV by ELISA. The symptoms we observed in lisianthus due to infection by INSV were more severe than those previously reported in this host (1,2). The occurrence of such strains of INSV at high incidences could pose a significant threat for commercial lisianthus production. References: (1) M. K. Hausbeck et al. Plant Dis. 76:795, 1992. (2) H. T. Hsu and R. H. Lawson. Plant Dis. 75:292,1991.


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