Additional Ornamental Species as Hosts of Impatiens Necrotic Spot Tospovirus in Italy

Impatiens necrotic spot (INSV) and tomato spotted wilt (TSWV) tospoviruses are among the most important viral pathogens of glasshouse ornamental plants worldwide (1). Tospovirus infections drastically reduce the market value of plants and create certification problems for international traders. As with TSWV, the number of natural host species recorded for INSV is steadily increasing (2). In 1998, severe INSV infections were found on different ornamental plants in glasshouses in the Piedmont Region of northwestern Italy, together with heavy infestations of the thrips Frankliniella occidentalis. A high proportion of plants were infected with INSV, as shown by enzyme-linked immunosorbent assay (ELISA) with polyclonal antisera and monoclonal antibodies against its nucleocapsid protein. Results were confirmed by sap-inoculation to indicator hosts. Some species were already known to be susceptible to INSV, but others are apparently new hosts (2): Ageratum houstonianum (Asteraceae), showing small necrotic rings and leaf malformation; Cordyline terminalis (Agavaceae), showing chlorotic-necrotic ringspots and leaf malformation; Dianthus chinensis (Caryophyllaceae), showing stunting, mosaic, and leaf malformation (some plants had symptomless infections); Episcia capreata (Gesneriaceae), showing necrotic spots on stems and leaves; Godetia grandiflora (Onagraceae), showing necrotic rings; Maranta leuconeura (Marantaceae), showing chlorotic-necrotic spots and apical malformation; Peperomia obtusifolia (Piperaceae), showing necrotic ringspots and leaf malformations; Scindapsus aureus (Araceae), showing necrotic spots and rings; Torenia fournieri (Scrophulariaceae), showing necrosis on stems and apexes. Thrips feeding damage was high on some species, particularly those showing necrotic ringspot symptoms. It often was difficult to distinguish between true systemic symptoms and local INSV infection at thrips feeding sites. Capsicum sp., Coleus blumei, and Dahlia sp., which also were infected in our study, are species known to be infrequent hosts of INSV (2). References: (1) M. L. Daughtrey et al. Plant Dis. 81:1220, 1997. (2) D. Peters. 1998. Pages 107–110 in: Abstr. 4th Int. Symp. Tospovirus Thrips Floral Vegetable Crops. University of Wageningen, The Netherlands.

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First Report of Impatiens necrotic spot virus Infecting Lettuce in California

Plant Disease ◽

10.1094/pdis-92-8-1248a ◽

2008 ◽

Vol 92 (8) ◽

pp. 1248-1248 ◽

Cited By ~ 4

Author(s):

S. T. Koike ◽

Y.-W. Kuo ◽

M. R. Rojas ◽

R. L. Gilbertson

Keyword(s):

Frankliniella Occidentalis ◽

Disease Incidence ◽

Pcr Analysis ◽

Impatiens Necrotic Spot Virus ◽

Vegetable Crops ◽

Necrotic Spot ◽

Rt Pcr ◽

Spot Virus ◽

First Report ◽

Monterey County

Impatiens necrotic spot virus (INSV; family Bunyaviridae, genus Tospovirus) is an important pathogen of ornamental plants in North America and Europe, particularly in the greenhouse industry (2,3). However, INSV is now emerging as a pathogen of vegetable crops. During the 2006 and 2007 growing seasons, lettuce (Lactuca sativa) in Monterey County, CA showed necrotic spotting, leaf chlorosis, and plant stunting typical of symptoms induced by Tomato spotted wilt virus (TSWV). Significant and damaging outbreaks of these disease symptoms were found in numerous romaine, greenleaf, redleaf, butterhead, and iceberg lettuce fields in Monterey and San Benito counties. Samples from symptomatic plants from 21 of 27 fields in Monterey County were negative when tested with TSWV immunostrips (Agdia, Elkhart, IN); however, tests of the TSWV-negative samples with INSV immunostrips were positive. In most fields where INSV was detected, disease development was limited to the edges of fields and disease incidence was <5%; however, some fields had incidences >50% and crop loss was experienced. The virus causing the tospovirus symptoms in the TSWV-negative lettuce was sap transmitted to Nicotiana benthamiana and lettuce, where it induced chlorosis and necrosis. Symptoms in N. benthamiana were consistent with INSV infection, and those in lettuce were similar to symptoms observed in the field. Immunostrip tests confirmed that symptomatic N. benthamiana and lettuce plants were infected with INSV. To further confirm the identity of this virus, reverse transcription (RT)-PCR analysis was conducted with an INSV primer pair that directs the amplification of a ~1.3-kb fragment from the small RNA of INSV (4). The 1.3-kb fragment was amplified from RNA from symptomatic lettuce plants that were INSV positive with immunostrips, and not from asymptomatic lettuce. A total of 38 of 54 samples showing tospovirus-like symptoms were confirmed to be infected with INSV by RT-PCR. Sequences of two representative 1.3-kb DNA fragments were 98 to 99% identical with sequences of INSV isolates from Japan, Italy, and The Netherlands (GenBank Accession Nos. AB109100, DQ425096, and X66972). Taken together with the previous identification of the INSV vector, the western flower thrips (Frankliniella occidentalis), in central California lettuce (1), these results confirm that INSV induced tospovirus symptoms in lettuce fields in Monterey County in 2007. To our knowledge, this is the first report of the occurrence of INSV infecting lettuce in California. References: (1) W. E. Chaney. Annu. Rep. California Lettuce Res. Board. 2006. (2) M. Daughtrey et al. Plant Dis. 81:1220, 1997. (3) M. D. Law and J. W. Moyer. J. Gen. Virol. 71:933, 1990. (4) R. A. Naidu et al. Online publication. doi: 10.1094/PHP-2005-0727-01-HN. Plant Health Progress, 2005.

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Partial sequencing of a putative Alstroemeria necrotic streak orthotospovirus isolate detected on lettuce in Colombia

Pesquisa Agropecuária Tropical ◽

10.1590/1983-40632021v5168585 ◽

2021 ◽

Vol 51 ◽

Author(s):

Diego Alejandro Jurado-Rincón ◽

Linda Jeimmy Rincón-Rivera ◽

Angela María Vargas-Berdugo ◽

Adriana González-Almario

Keyword(s):

Viral Infection ◽

N Gene ◽

Enzyme Linked Immunosorbent Assay ◽

Necrotic Spot ◽

Partial Sequencing ◽

Tomato Spotted Wilt ◽

Foliar Symptoms ◽

Necrotic Spots ◽

Leaf Distortion ◽

Das Elisa

ABSTRACT Lettuce is the most cultivated leafy salad vegetable in Colombia, being the municipality of Madrid, in the Department of Cundinamarca, the second largest producer. In this region, lettuce plants with foliar symptoms characterized by brown necrotic spots forming an extended necrotic area, chlorosis, leaf distortion and plant stunting have been detected, possibly caused by a viral infection associated with the Orthotospovirus genus. This study aimed to identify the orthotospovirus species associated with those symptoms, contributing to updating the lettuce phytosanitary status in this region. The presence of orthotospovirus was confirmed by the enzyme-linked immunosorbent assay (DAS-ELISA), although the sequence of the nucleocapsid (N) gene confirmed the presence of Alstroemeria necrotic streak orthotospovirus, disregarding the Tomato spotted wilt orthotospovirus and Impatiens necrotic spot orthotospovirus previously reported for this crop, being this its first report in lettuce crops in Colombia.

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Impatiens necrotic spot virus. [Distribution map].

Distribution Maps of Plant Diseases ◽

10.1079/dmpd/20073069781 ◽

2007 ◽

Author(s):

Keyword(s):

New York ◽

South Carolina ◽

Frankliniella Occidentalis ◽

Ornamental Plants ◽

Impatiens Necrotic Spot Virus ◽

Necrotic Spot ◽

Distribution Map ◽

Spot Virus ◽

Virus Distribution ◽

Distribution In Europe

Abstract A new distribution map is provided for Impatiens necrotic spot virus. Bunyaviridae: Tospovirus. Hosts: daisy (Chrysanthemum), balsam (Impatiens) and some other ornamental plants. Information is given on the geographical distribution in Europe (Austria, Belgium, Czech Republic, Finland, France (mainland France), Germany, Hungary, Italy (mainland Italy, Sicily), Netherlands, Poland, Portugal, Slovenia, Spain, UK (England and Wales)), Asia (Iran, Israel, Japan (Honshu)), North America (Canada (Alberta, British Columbia, Manitoba, Ontario, Quebec), Mexico, USA (Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Idaho, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Minnesota, Mississippi, Missouri, New Hampshire, New Jersey, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, South Carolina, Texas, Vermont, Virginia)), Central America and Caribbean (Costa Rica), South America (Chile), Oceania (New Zealand). It is vectored by Frankliniella occidentalis (Thysanoptera: Thripidae).

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First Report of Impatiens Necrotic Spot Tospovirus (INSV) in Israel

Plant Disease ◽

10.1094/pdis.1999.83.6.587a ◽

1999 ◽

Vol 83 (6) ◽

pp. 587-587 ◽

Cited By ~ 5

Author(s):

A. Gera ◽

A. Kritzman ◽

J. Cohen ◽

B. Raccah

Keyword(s):

Frankliniella Occidentalis ◽

Western Flower Thrips ◽

Enzyme Linked Immunosorbent Assay ◽

Necrotic Spot ◽

First Report ◽

Flower Thrips ◽

Transmission Electron ◽

Strong Positive Reaction ◽

Symptomatic Tissue ◽

Wilt Virus

In January 1999, Anemone coronaria L. imported from Europe and grown in open fields near Jerusalem in Israel developed foliar ringspots and foliar necrosis. Within a few weeks of the first appearance of these symptoms, further anemone plants in the surrounding area were affected and seriously damaged. Impatiens necrotic spot tospovirus (INSV) was detected in affected plants by enzyme-linked immunosorbent assay (ELISA; anti-INSV monoclonal antibodies were provided by H. T. Hsu, USDA, Beltsville, MD, and a polyclonal antibody to INSV was purchased from Loewe, Otterfing, Germany). Crude sap extracted from symptomatic tissue was mechanically transmitted to Emilia spp., Petunia hybrida, Nicotian glutinosa, N. benthamiana, and N. rustica plants that developed symptoms characteristic of INSV infection (1). ELISAs of leaf sap extracted from anemone plants and mechanically inoculated indicator plants gave a strong positive reaction to INSV. Leaf-dip preparations prepared from leaf samples of anemone plants were analyzed by transmission electron microscopy (TEM). Virus particles typical of a tospovirus were observed in samples taken only from symptomatic plants. TEM studies with ultrathin sections of infected anemone and Emilia spp. leaves revealed the presence of tospovirus-like particles. This first report of INSV interception in Israel brings the count of the Tospovirus members in Israel to three, including tomato spotted wilt virus (TSWV), which was found in the past to infect anemone and other ornamental crops, and the Iris yellow spot tospovirus, infecting onion (2). INSV is known to occur in Europe and in the U.S., mostly in flowers grown in greenhouses. The virus is transmitted by the Western flower thrips (WFT; Frankliniella occidentalis Pergande). Although all infected plants were destroyed, precautions to prevent further introduction of the virus must be made. INSV might spread by the WFT, which is abundant in Israel year round, and might also infect other greenhouse or field crops. References: (1) M. Daughtrey et al. Plant Dis. 81:1220, 1997. (2) A. Gera et al. Plant Dis. 82:127, 1998.

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First Report of Impatiens necrotic spot virus in the Czech Republic

Plant Disease ◽

10.1094/pdis.2000.84.9.1045b ◽

2000 ◽

Vol 84 (9) ◽

pp. 1045-1045 ◽

Cited By ~ 4

Author(s):

J. Mertelik ◽

V. Mokra ◽

B. Gotzova ◽

S. Gabrielova

Keyword(s):

Czech Republic ◽

Plant Species ◽

Frankliniella Occidentalis ◽

Impatiens Necrotic Spot Virus ◽

Enzyme Linked Immunosorbent Assay ◽

Necrotic Spot ◽

Weed Species ◽

Stellaria Media ◽

Spot Virus ◽

The Czech Republic

Impatiens necrotic spot virus (INSV) was found for the first time in the Czech Republic in 1999 in Columnea sp. and Curcuma sp. plants that were imported. They were grown in a garden among other ornamental crops. By June 2000, INSV was detected in 17 ornamental plant species in several gardening establishments never having received imported plants. Frankliniella occidentalis thrips were present at the sites of INSV infection. Natural INSV infection was found also in Stellaria media, which is an important weed species in our conditions. INSV was identified by enzyme-linked immunosorbent assay using polyclonal antibodies to INSV from Loewe Biochemica, Germany, and from Bioreba, Switzerland. The virus was transmitted in sap to Nicotiana benthamiana and Datura stramonium (1). Virus particles typical of a tospovirus were detected by electron microscopy. INSV is the second tospovirus member occurring in the Czech Republic. Tomato spotted wilt virus (TSWV) has occurred in this country since 1992 (2) and to date has been detected in more than 100 plant species including ornamentals, vegetables, and weeds. TSWV became a serious problem in glasshouse grown crops. From the epidemiological point of view the situation of INSV dissemination seems to be similar to that of TSWV. References: (1) M. Daughtrey et al. Plant Dis. 81:1220, 1997. (2) J. Mertelik and V. Mokra. Acta Virol. 42:348, 1998.

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Occurrence of Impatiens necrotic spot virus in Ornamentals in Mahallat and Tehran Provinces in Iran

Plant Disease ◽

10.1094/pdis.2002.86.6.694a ◽

2002 ◽

Vol 86 (6) ◽

pp. 694-694 ◽

Cited By ~ 29

Author(s):

N. Shahraeen ◽

T. Ghotbi ◽

A. H. Mehraban

Keyword(s):

Ornamental Plants ◽

Dianthus Caryophyllus ◽

Positive Control ◽

Thrips Tabaci ◽

Impatiens Necrotic Spot Virus ◽

Enzyme Linked Immunosorbent Assay ◽

Necrotic Spot ◽

Spot Virus ◽

Chenopodium Amaranticolor ◽

Severity Of The Disease

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.

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Increased Interleukin-6 Levels in Nasal Lavage Samples following Experimental Influenza A Virus Infection

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.5.5.604-608.1998 ◽

1998 ◽

Vol 5 (5) ◽

pp. 604-608 ◽

Cited By ~ 57

Author(s):

Deborah Gentile ◽

William Doyle ◽

Theresa Whiteside ◽

Philip Fireman ◽

Frederick G. Hayden ◽

...

Keyword(s):

Virus Infection ◽

Influenza A Virus ◽

Interleukin 6 ◽

Influenza A ◽

Respiratory Infections ◽

Nasal Lavage ◽

Enzyme Linked Immunosorbent Assay ◽

Influenza A Virus Infection ◽

Systemic Symptoms ◽

Experimental Influenza

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.

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Detection of a Severe Isolate of Impatiens Necrotic Spot Virus Infecting Lisianthus in Florida

Plant Disease ◽

10.1094/pdis.1997.81.11.1334b ◽

1997 ◽

Vol 81 (11) ◽

pp. 1334-1334 ◽

Cited By ~ 3

Author(s):

R. J. McGovern ◽

J. E. Polston ◽

B. K. Harbaugh

Keyword(s):

Leaf Tissue ◽

Impatiens Necrotic Spot Virus ◽

Enzyme Linked Immunosorbent Assay ◽

Mechanical Transmission ◽

Necrotic Spot ◽

Spot Virus ◽

Eustoma Grandiflorum ◽

Systemic Necrosis ◽

Low Incidence ◽

Leaf Distortion

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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First Report of a Tobamovirus in Dieffenbachia and Impatiens

Plant Disease ◽

10.1094/pdis.2000.84.6.707a ◽

2000 ◽

Vol 84 (6) ◽

pp. 707-707 ◽

Cited By ~ 2

Author(s):

E. B. Rivas ◽

E. F. Pezani ◽

M. A. V. Alexandre ◽

L. M. L. Duarte

Keyword(s):

Ornamental Plants ◽

Start Codon ◽

Enzyme Linked Immunosorbent Assay ◽

Mechanical Transmission ◽

Reaction Products ◽

Cp Gene ◽

Gomphrena Globosa ◽

Leaf Deformation ◽

Antisense Primer ◽

Impatiens Hawkeri

Tobamoviruses were detected in two ornamental plants, Dieffenbachia picta (Araceae) and Impatiens hawkeri (Balsaminaceae), from different counties in São Paulo State, Brazil. Symptoms were chlorotic spots and rings in D. picta and mosaic, blistering, and leaf deformation in I. hawkeri. Mechanical transmission from both species induced different kinds and intensities of symptoms in the same experimental hosts (Balsaminaceae, Chenopodiaceae, and Solanaceae), except Gomphrena globosa, which was infected only by the isolate from D. picta. The viruses did not infect Cucurbitaceae and Fabaceae. Indirect enzyme-linked immunosorbent assay performed with extracts from infected Nicotiana tabacum ‘White Burley’ and antisera against Cucumber green mottle, mosaic, Frangipani mosaic, Odontoglossum ringspot, Ribgrass mosaic, Tobacco mosaic (TMV), Tomato mosaic, Turnip vein clearing, and Youcai mosaic viruses (genus To-bamovirus) was positive only for TMV. Furthermore, the viruses isolated from D. picta and I. hawkeri cross-reacted with their heterologous antisera. Two sense primers for regions ≍200 and 90 nt upstream of the start codon and an antisense primer ≍60 nt downstream of the terminal codon of the coat protein (CP) gene were designed for two amplification assays. Migrating fragments the same size as the reverse-transcription polymerase chain reaction products from the TMV type strain (479 and 800 bp with internal and external primers, respectively) were produced. The CP gene sequence will allow comparison and identification of the two viruses isolated from D. picta and I. hawkeri.

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First Report of Cucurbit yellow stunting disorder virus in Morocco

Plant Disease ◽

10.1094/pdis.2000.84.5.596c ◽

2000 ◽

Vol 84 (5) ◽

pp. 596-596 ◽

Cited By ~ 24

Author(s):

C. Desbiez ◽

H. Lecoq ◽

S. Aboulama ◽

M. Peterschmitt

Keyword(s):

Important Change ◽

Enzyme Linked Immunosorbent Assay ◽

Yellow Leaf ◽

Vegetable Crops ◽

Specific Primers ◽

First Report ◽

Large Populations ◽

Healthy Control ◽

Symptomless Plant ◽

Beet Pseudo Yellows Virus

In October, 1999, severe yellowing symptoms were observed in a melon (Cucumis melo L.) crop grown under plastic tunnels in the region of Agadir, Morocco. Large populations of whiteflies (Bemisia tabaci) were noticed during the early stages of the crop. At harvest, leaf samples were collected from two symptomatic plants and one symptomless plant. A mature yellow leaf was assayed from each symptomatic plant and for one of these two plants a younger leaf exhibiting only yellow spots. Cucurbit aphid-borne yellows virus, which causes similar symptoms in melons, was not detected by double-antibody sandwich enzyme-linked immunosorbent assay tests. Total RNA was extracted from fresh leaf tissues and submitted to reverse transcription and polymerase chain reaction with primers specific to two whitefly-transmissible viruses: Beet pseudo-yellows virus (BPYV) and Cucurbit yellow stunting disorder virus (CYSDV) (2). No amplification was obtained with BPYV-specific primers. In contrast, an expected 465-bp product was amplified in all samples from symptomatic plants with CYSDV-specific primers. No amplification was detected in samples from the symptomless plant nor from healthy control plants. B. tabaci-transmitted CYSDV has been reported in the Middle East, southwestern Europe, and North America (1,4). This is the first report of CYSDV in Morocco, and it follows the first report of another B. tabaci-transmitted virus, Tomato yellow leaf curl virus, in tomato (3), suggesting an important change in the viral pathosystem affecting vegetable crops in Morocco. References: (1) Kao et al. Plant Dis. 84:101, 2000. (2) Livieratos et al. Plant Pathol. 47:362, 1998. (3) Peterschmitt et al. Plant Dis. 83:1074, 1999. (4) Wisler et al. Plant Dis. 82:270, 1998.

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