Damage to agricultural crops by tospoviruses has occurred sporadically in Iran in the past; however, since 2000, outbreaks of tospoviruses have been recorded every year. The most affected ornamental crops were surveyed in two main cultivation areas in provinces of Markazi (Mahallat) and Tehran in 2000-01 and 2001-02. A few weed species also were collected. In all, 513 samples (with or without any conspicuous virus symptoms) were collected and analyzed by double- and triple-antibody sandwich enzyme-linked immunosorbent assay (ELISA) with polyclonal antibodies to Tomato spotted wilt virus (TSWV), Impatiens necrotic spot virus (INSV), and Tomato Varamin virus (ToVV), a new Tospovirus sp. from Iran. These viruses frequently were detected in samples of many different ornamentals and often in mixed infections, whereas Iris yellow spot virus (IYSV) was detected in only four samples. ToVV also was found in weeds growing in Chrysanthemum fields and in a Cuscuta sp. Applying double-antibody sandwich ELISA, no positive reactions were found with Tomato chlorotic spot virus (TCSV). Of the total of 513 samples tested, 345 samples did not react with any Tospovirus antisera. In Tehran, INSV was identified in 21 samples (10%), IYSV in 4 samples (2%), TSWV in 16 samples (8%), and ToVV in 22 samples (11%). In Markazi province, INSV was identified in 24 samples (8%), IYSV in 1 sample (0.5%), TSWV in 40 samples (13%), and ToVV in 36 samples (12%). ToVV was found to prevail in Tehran province and TSWV in Markazi. Thrips spp. present at the plant sampling sites also were collected and identified.

Surveys to identify virus diseases affecting garlic (Allium sativum), onion (Allium cepa) and Persian leek (Allium ampeloprasum var. persicum) were conducted from 1999 to 2002. Surveys covered different regions of Iran (Tehran [different vegetable markets, farmer fields and cultivation areas], Noushahr, Chalous, Roudbar, Sari, Hamadan, Touyserkan, Ghazvin and Jiroft). A total of 2045 (1285 garlic, 525 onion and 230 leek) samples showing symptoms of virus infection were collected and tested by ELISA; and in some cases tests were also confirmed by immunoelectron microscopy (IEM) for the presence of Allium viruses. ELISA results showed that the following viruses were detected: Onion yellow dwarf virus (OYDV), Leek yellow stripe virus (LYSV) (genus Potyvirus, family Potyviridae), Garlic common latent virus (GarCLV), Shallot latent virus (SLV) (genus Carlavirus), Garlic virus D (GarV‐D), Garlic virus B (GarV‐B) and Garlic virus C type (GarV‐C) (genus Allexivirus). None of the samples reacted with antibodies to Shallot yellow stripe virus (SYSV) genus Potyvirus, family Potyviridae), Shallot virus X (ShVX) and Garlic virus A (GarV‐A, genus Allexivirus). GarCLV, SLV, GarV‐D, GarV‐B and GarV‐C are reported for the first time from Allium crops in Iran.

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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.