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During the summer of 2003, weed samples of Rapistrum rugosum and Sisymbrium loeselii showing severe mosaic, malformation, and stunting were collected from cauliflower fields in Tehran Province of Iran. Using double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) with specific polyclonal antibodies, the samples were tested for the presence of Beet western yellows virus, Cauliflower mosaic virus, Radish mosaic virus, Turnip crinkle virus, Turnip mosaic virus (TuMV) (DSMZ, Braunschweig, Germany), Cucumber mosaic virus, and Tobacco mosaic virus (Sanofi Diagnostics Pasteur, Marnes-La-Coquette, France). Leaf extracts were used for mechanical inoculation and they produced chlorotic local lesions on Chenopodium amaranticolor, necrotic lesions on leaves and shoot apex necrosis on Nicotiana glutinosa, leaf deformation, mosaic, and stunting on Petunia hybrida, and severe mosaic, distortion, and stunting on Brassica rapa. These symptoms were similar to those that were described previously for TuMV (4). ELISA results showed that the original leaf samples and inoculated indicator plants reacted positively with TuMV antibodies, but not with antibodies for any of the other viruses listed above. Also, reverse transcription-polymerase chain reaction of total RNA extracted from the collected leaf samples using the universal primers for potyviruses (3) resulted in the amplification of two fragments of the expected sizes, approximately 700 and 1,700 bp. TuMV, a member of the genus Potyvirus in the family Potyviridae, is transmitted by aphids in a nonpersistent manner (4). This virus is geographically widespread with a wide host range that can infect 318 species in 156 genera of 43 plant families including, Brassicaceae, Chenopodiaceae, Asteraceae, Cucurbitaceae, and Solanaceae (2,4). R. rugosum and S. loeselii, two annual or biennial plants in the Brassicaceae family, were common and widely distributed in the fields surveyed. The presence of TuMV-infected weed hosts in cauliflower fields may impact disease management strategies. TuMV was first observed on stock plants (Matthiola sp.) in Iran (1). To our knowledge, this is the first report of natural occurrence of TuMV on weed hosts in Iran. References: (1) M. Bahar et al. Iran. J. Plant Pathol. 21:11, 1985. (2) J. R. Edwardson and R. G. Christie. The potyvirus group. Fla. Agric. Exp. Stn. Monogr. Ser. No. 16, 1991. (3) A. Gibbs and A. Mackenzie. J. Virol. Methods 63:9, 1997. (4) J. A. Tomlinson. Turnip mosaic virus. No. 8 in: Descriptions of Plant Viruses. CMI/AAB, Surrey, England, 1970.

During the 2001 growing season, a survey was conducted to determine the incidence of Beet necrotic yellow vein virus (BNYVV), Beet soilborne virus (BSBV), and Beet virus Q (BVQ) in Iran. A total of 2,816 random and 76 samples with rhizomania were collected from 131 fields in the main sugar beet cultivation areas of 13 provinces in Iran. All samples were tested using a tissue-blot immunoassay (TBIA) with commercial BNYVV (As-0799.1/CG6-F4), BSBV (As-0576.1), and BSBV/BVQ (As-0576.2) antisera provided by S. Winter (DSMZ, Braunschweig, Germany). For randomly collected samples, the highest incidence of virus infection was found for BNYVV (52.3%), followed by BSBV (9.5%) and BVQ (1.5%). Co-infection of BNYVV with BSBV or BVQ was 6.6% and 0.9%, respectively. Infection with both BSBV and BVQ was found in 16 (0.6%) samples. In addition, 0.4% (12) of the samples was infected with all three viruses. Our results indicated the presence of BVQ in samples from 10 fields located in Azarbayejan-e-gharbi, Esfahan, Fars, Kermanshah, Khorasan, Lorestan, and Semnan provinces of Iran, with or without rhizomania-like symptoms. The presence of viruses was confirmed using reverse transcription-polymerase chain reaction (RT-PCR) of RNA from 81, 19, and 14 root samples with positive reaction in TBIA to BNYVV, BSBV, and BVQ, respectively, with previously described primers (3,4). The primers specifically amplified fragments of 501 bp, 602 bp, 399 bp, and 291 bp of the BNYVV RNAs 1 and 4, BSBV RNA-2, and BVQ RNA-1, respectively. Our results indicated that the samples tested were also positive using RT-PCR. The putative vector for BNYVV, BSBV, and BVQ, Polymyxa betae, was also detected in 161 samples (from 127 fields) by amplification of a 170-bp fragment of the P. betae repetitive EcoRI-like fragments using previously described primers (4). RT-PCR products from 72 BNYVV-positive sugar beet root samples from 58 fields that also gave positive reactions in TBIA were analyzed using single-strand conformation polymorphism (SSCP) as previously described with extracts from root beards of the susceptible sugar beet cvs. OPUS and IC1 grown in the soils infested with BNYVV types A and B (provided by A. Meunier, Unite de Phytopathologie-UCL-AGRO-BAPA, Louvain-la-Neuve, Belgium) as positive controls (3). The patterns obtained with SSCP were uniform and showed widespread occurrence of BNYVV type A in almost all provinces surveyed. The fragments obtained for BNYVV RNAs 1 and 4 of an isolate from Qazvin (BNQ1) were sequenced (GenBank Accession Nos. AY703452 and AY703455) and compared with other sequences available in GenBank using Clustal W, which revealed 99.3 and 99.6% identity with the Japanese S (D84410) and Italian type A (AF197552) isolates, respectively. The economic importance of BVQ and its interactions with other sugar beet soilborne viruses remains a matter of debate. BNYVV and BSBV have been previously reported from Iran (1,2). To our knowledge, this is the first report of the natural occurrence of BVQ in sugar beets in Iran. References: (1) Sh. Farzadfar et al. Plant Dis. 86:187, 2002. (2) K. Izadpanah et al. Iran. J. Plant Pathol. 32:155, 1996. (3) R. Koenig et al. J. Gen. Virol. 76:2051, 1995. (4) A. Meunier et al. Appl. Environ. Microbiol. 69:2356, 2003.

The main areas for field-grown sugar beet (Beta vulgaris) production in Iran were surveyed to study the occurrence and incidence of Alfalfa mosaic virus (AlMV), Beet curly top virus (BCTV), Beet mosaic virus (BtMV), Beet western yellows virus (BWYV), Beet yellows virus (BYV), Chickpea chlorotic dwarf virus (CpCDV), Cucumber mosaic virus (CMV), and Turnip mosaic virus (TuMV) during the growing season of 2001. A total of 5,292 random leaf samples in addition to 1,294 symptomatic leaves were collected from nine commercial sugar beet growing provinces of Iran and tested by tissue-blot immunoassay (TBIA). Serological diagnoses were confirmed by electron microscopy and host range studies. The highest virus incidence among the surveyed provinces was recorded in Qazvin, followed by Fars, Esfahan, Azarbayejan-e-gharbi, Khorasan, Kermanshah, Semnan, and Hamedan. According to the TBIA results, viruses in decreasing order of incidence in sugar beet were BCTV (27.9%), followed by BWYV (17.4%), CpCDV (12.5%), BYV (10.6%), BtMV (7.4%), TuMV (2.9%), AlMV (1.3%), and CMV (1.2%). Nearly 35% of sugar beets in Iran were infected by one or both of the two leafhopper-transmitted viruses (BCTV and CpCDV). Moreover, about 28% were infected by at least one of the six aphid-transmitted viruses (AlMV, BWYV, BtMV, BYV, CMV, and TuMV). Overall, one or more of the eight viruses assayed were detected in 45.5% of the plants surveyed. Several plants (35%) displaying virus-like symptoms did not react with the virus antisera used, suggesting that more viruses or virus-like agents are infecting sugar beets in Iran. In reference to the earlier reports, this is the first report of AlMV and TuMV in sugar beet fields of Iran. Also, this is the first detection of CpCDV as a pathogen of sugar beet.

From a total of 8,135 potato leaves collected from 132 fields in 11 provinces of Iran, the incidence and distribution of Alfalfa mosaic virus (AlMV), Eggplant mottled dwarf virus (EMDV), Potato leafroll virus (PLRV), Potato virus A (PVA), Potato virus M (PVM), Potato virus S(PVS), Potato virus X (PVX), Potato virus Y (PVY), and Tomato yellow fruit ring virus (TYFRV) were assessed using serological and biological methods. Based on enzyme-linked immunosorbent assay (ELISA) results, viruses in decreasing order of incidence in potato were PVS (35.9%), PVY (34.4%), PVA (27.0%), PVX (20.8%), PLRV (13.9%), PVM (9.0%), AlMV (7.0%), TYFRV (5.9%), and EMDV (5.1%). All 132 fields surveyed had some degree of virus infection, ranging from 28.8 to 98.6%, with an overall incidence of 75.2%. The highest and lowest incidence of virus infections among the surveyed provinces occurred in Kerman (93.2%) and Ardabil (56.7%), respectively. Overall, 25.0 and 50.2% of the collected potato samples had single or mixed infections, respectively. High levels of mixed infections were found between PVX and PVS (8.6%), and PVX and PVY (7.6%). Moreover, co-infection of samples with PVS and PVY, PVA and PVS, and PVA and PVY, the aphid-vectored virus/virus combinations, occurred at the highest incidence in almost all provinces surveyed, 15.3, 13.8, and 12.8%, respectively. In this study, Beet curly top virus was detected in symptomatic potato samples collected from some fields in the Kermanshah province.

A distinct isolate (TY-PF36) of Tomato yellow fruit ring virus (TYFRV) was obtained from potato (Solanum tuberosum) in Iran. Chlorosis and necrotic spots on leaves associated with leaf and stem necrosis symptoms appear on the affected plants. Of 32 plant species and cultivars mechanically inoculated, 24 were susceptible to the virus isolate. The isolate strongly reacted with TYFRV antibodies in enzyme-linked immunosorbent assay (ELISA), but not with the specific antibodies of other tospoviruses tested. TYFRV-specific N gene primers described previously, however, failed to produce DNA fragments from the total RNA extracts of the infected plants in reverse transcription–polymerase chain reaction (RT-PCR). Nucleotide sequencing of the complete N gene and partial L gene of this isolate revealed considerable differences to those reported for TYFRV with identities ranging from 83.9 to 84.2% and 84.9 to 85.4%, respectively. Two specific primers were designed for detecting TY-PF36 using RT-PCR; TY-PF36 was detected in symptomatic field samples of potato, peanut, soybean, and two weed species, Datura metel and D. stramonium.

Beet yellows virus (BYV), a member of the Closteroviridae family, is one of the most important sugar beet yellowing viruses. The nine ORFs of BYV genome encode different proteins required for BYV life cycle. We sequenced a part of the genome of BYV Iranian isolate consisting of ORF6, ORF7 and ORF8. The primer pair BYVA/Z was used for amplification of this region in RT-PCR. The amplicon (1615 bp) was cloned and sequenced. Comparisons showed the amplified segment is corresponding to ORF6, ORF7 and ORF8 of BYV genome encoding coat protein, p20 and p21 proteins, respectively. The ORF7 of BYV Iranian isolate overlaps with ORF6 and ORF8 in four and 26 nucleotides at 5′ and 3′ ends, respectively. The ORF7 of Iranian isolate of BYV was sequenced completely. However, approximately 24 nt. from the beginning of ORF6 and 23 nt. from end of ORF8, including the stop codon, were not determined. ORF6, ORF7 and ORF8 showed the highest similarity at nucleotide (98.3, 99.4 and 99.2%) and amino acid (97.4, 98.9 and 100%) sequence levels, with BYV Ukrainian isolate. Phylogenetic analysis of the deduced amino acid sequences of ORF6, ORF7 and ORF8 revealed closer relationship of Iranian isolate of BYV with BYV Ukrainian isolate than other BYV isolates available at GenBank.

Recently, peach trees showing leaf rolling, little leaf, rosetting, yellowing, bronzing of foliage and tattered and shot-holed leaves symptoms were observed in peach growing areas in the central and north-western regions of Iran. Polymerase chain reaction (PCR) and nested PCR using phytoplasma universal primer pairs PI/Tint, R16F2/R2, PA2F/R and NPA2F/R were employed to detect phytoplasmas. The nested PCR assays detected phytoplasma infections in 51% of symptomatic peach trees in the major peach production areas in East Azerbaijan, Isfahan, ChaharMahal-O-Bakhtiari and Tehran provinces. Restriction fragment length polymorphism (RFLP) analyses of 485 bp fragments amplified using primer pair NPA2F/ R in nested PCR revealed that the phytoplasmas associated with infected peaches were genetically different and they were distinct from phytoplasmas that have been associated with peach and almond witches'-broom diseases in the south of Iran. Sequence analyses of partial 16S rDNA and 16S-23S rDNA intergenic spacer regions demonstrated that 'Candidatus Phytoplasma aurantifolia', 'Ca. Phytoplasma solani' and 'Ca. Phytoplasma trifolii' are prevalent in peach growing areas in the central and north-western regions of Iran.

In recent years, almond witches’-broom disease has been prevalent in almond growing areas in the centre and south of Iran. Furthermore, almond trees showing different symptoms of phytoplasma diseases such as little leaf, leaf rolling, dieback of branches, rosette and yellowing were observed in the central regions of Iran. DNA isolated from symptomatic almond trees was used to amplify 16S rDNA and 16S-23S rDNA intergenic spacer (IS) fragments by nested polymerase chain reaction (PCR) using phytoplasma universal primer pairs (P1/P7, R16F2/R2, PA2F/R and NPA2F/R). Phytoplasmas were detected in symptomatic almonds in two major almond-growing regions, Isfahan and ChaharMahal-O-Bakhtiari. Restriction fragment length polymorphism analyses of nested PCR products using endonuclease enzymes HpaII and TaqI revealed that phytoplasmas associated with infected almonds are genetically different. Sequence analyses of amplified fragments of 16S rDNA and IS region indicated that the almond phytoplasmas in Iran are closely related to ‘Candidatus (Ca.) Phytoplasma aurantifolia’, ‘Ca. Phytoplasma phoenicium’, ‘Ca. Phytoplasma solani’ and ‘Ca. Phytoplasma trifolii’. The phytoplasmas related to ‘Ca. Phytoplasma aurantifolia’ were more prevalent than other phytoplasmas in the central regions of Iran.

Five isolates of Grapevine fanleaf virus (GFLV) collected from two viticultural regions in the north-east of Iran were characterized based on coat protein (CP) gene sequences. The CP gene of all isolates was amplified by reverse transcription-polymerase chain reaction (RT-PCR) using its specific primers, yielding a 1500bp amplicon. The nucleotide sequences for these isolates were obtained and compared with the CPI region of seven isolates from north-west Iran and also with some other exotic GFLV-CP sequences available in the GenBank. Analysis of our data revealed that the north-east Iranian sequences have 83.7–87.5% of homology with the CPI regions of exotic GFLV isolates, and 83.0–87.1% homology with other isolates from north-west Iran. High nucleotide homology (98.6–100%) was found among the GFLV isolates sequences obtained in this study. The deduced proteins obtained for our five isolates were 92.0–96.0% identical to other sequences. The generated phylogenetic tree revealed a clustering of GFLV isolates distributed over the world in one branch, and the Iranian isolates in other branches.

Virus like symptoms appeared on most watermelon plants grown at different locations in southern provinces of Iran. The symptoms included chlorotic patches on leaves, vein yellowing and stunting of watermelon plants. The causal agent of watermelon chlorotic stunt disease was transmitted to healthy watermelon, jimson-weed and bean by the whitefly Bemisia tabaci, but not by sap inoculation. Coat protein and nucleic acid of Watermelon chlorotic stunt virus (WmCSV) were detected in infected plants using a dot-immunobinding assay (DIBA) and squash-blot hybridization, respectively. The data obtained confirmed that watermelon chlorotic stunt disease in Iran is caused by WmCSV. Agroinoculation of some plant species by the cloned genomic components (DNA-A and DNA-B) of a non-sap-transmissible Iranian isolate of WmCSV (WmCSV-Ir) has been demonstrated. Host range studies using agroinoculation indicated that most plant species in the Cucurbitaceae and some species of the Solanaceae are susceptible to WmCSV-Ir. Infection of agroinoculated plants was confirmed by DIBA and polymerase chain reaction. The virus from agroinfected plants was transmissible by the whitefly Bemisia tabaci. Results obtained from a limited survey during 1997-2000 indicated the presence of WmCSV-Ir in some watermelon-growing provinces of southern but not in northern, central, and north-eastern provinces of Iran. WmCSV has apparently not yet spread to these regions.

Symptoms suggestive of phytoplasma diseases were observed in infected sweet cherry trees growing in the central regions of Iran. Phytoplasmas were detected in symptomatic trees by the nested polymerase chain reaction (nested PCR) using phytoplasma universal primer pairs (P1/Tint, PA2F/R, R16F2/R2 and NPA2F/R). Restriction fragment length polymorphism analyses of 485 bp DNA fragments amplified in nested PCR revealed that different phytoplamas were associated with infected trees. Sequence analyses of phytoplasma 16S rRNA gene and 16S-23S intergenic spacer region indicated that the phytoplasmas related to 'Ca. Phytoplasma asteris' and peanut WB group infect sweet cherry trees in these regions. This is the first report of the presence of phytoplasmas related to 'Ca. Phytoplasma asteris' and peanut WB group in sweet cherry trees.

MR. HAJIMORAD'*, A. KHEYR-POUR", V. ALAVJ", A. AHOONMANESH^,M.BAHAR'^t, M. A.REZAIAN'* and B. GRONENBORN''^ Plant Pests and Diseases Research Institute, PO Box 1454, Tehran-19395: and ^Department of PlantPathology, Esfahan University ofTeehnology. Esfahan; Iran"IfLstitut dcs Seiences Vegetales. CNRS. 91198 Gif-sur-Yvette Cedex, Franee^ of Horticulture, CSIRO. GPO Box 350, South Australia 5001. AustraliaA virtis causing a disease of tomato, prevaletit in the southern provinces of Iran, with symptoms of leaf-curling, stunting, reduction of leaf size, leaf corrugation, shortening of internodes and severe reductionin fruit yield, was shown to be transmissible to healthy tomato plants by grafting and by whiteflies{Beniisia (abaci), but not by sap inoculation. Geminivirus DNA was detected in extracts of diseasedtomato plants by dot-blot hybridization assays using as probes full-length cloned DNA of Australian,Italian {Sardinian) or Jordanian strains of tomato yellow leaf curl virus (TYLCV). Geminivirus coatprotein was detected in whitefly inoculated plants by dot immunobinding assay using polyclonalantibody raised against Jordanian TYLCV. A limited survey using the dot-blot hybridization assay forvirus detection indicated the presence of the virus in tomato-growing provinces of southern but notnorthern Iran. Whitefly transmission experiments to tomato under controlled greenhouse conditionsshowed that some isolates of TYLCV-like geminiviruses from different parts of Iran difFer insymptomatology.INTRODUCTIONA serious virus disease, which exhibits variousprominent symptoms such as upward curling ofleaf margins, stunting, reduction of leaf size atthe top of the plant, corrugated leaf, shorteningof internodes and severe reduction in fruit yield,has become prevalent in tomato fields all over theMiddle East (Makkouk & Laterrot, 1983).Similar symptoms have been described fromdiseased tomato plants in north and centralAfrica, south east Asia, Taiwan, Mexico, Italy(Sardinia), Spain, Australia, Dominican Repub-lic and Jamaica (Makkouk & Laterrot, 1983;Brown & Nelson, 1988; Czosnek et al., 1990;Kheyr-Pour et aL, 1991; Dry et al.. 1993;McGlashan et al., 1994; Noris et afA994\ Polston*Corresponding author.tPresent address: Department of Crop Protec-tion, Waitc Agricultural Research Institute, GlenOsmond, South Australia 5064, Australia.Accepted 15 November 1995.et al., 1994). The virus is transmitted by thewhitefly Bemisia tabaci (Cohen & Harpaz, 1964)but not mechanically (Cohen & Nitzany, 1966)and in all locations except Mexico has beencalled tomato yellow leaf curl geminivirus(TYLCV) (Brown & Nelson, 1988; Czosneket al., 1990; Kheyr-Pour et al., 1991; Dry et ai,1993; McGlashan et al.. 1994; Noris et al., 1994;Polston et ai., 1994). However, despite severalcommon characteristics between the virus foundin Mexico and TYLCV, the Mexican virus hasbeen called chino del tomate virus (Brown N Habibi, 1975; Javan-moghadam, 1993). In this report we describethe association of TYLCV with the disease inIran. We also indicate the distribution of the virusin Iran and describe symptom variation amongstvirus isolates from different parts of the country.

A survey was conducted from 2001 to 2004 in the major cucurbit-growing areas in Iran to reassess the relative incidence of cucurbit viruses. Severe yellowing symptoms were observed frequently on older leaves of cucurbit plants in various regions in outdoor crops, suggesting the presence of Cucurbit aphid-borne yellows virus (CABYV, genus Polerovirus, family Luteoviridae) (1,2). Leaf samples (n = 1019) were collected from plants of melon (Cucumis melo L.), cucumber (C. sativus L.), squash (Cucurbita sp.), and watermelon (Citrullus lanatus L.) showing various virus-like symptoms (mosaic, leaf deformation, yellowing). All samples, collected from 15 provinces, were screened for the presence of CABYV by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) with IgGs and alkaline phosphatase-conjugated IgGs against a CABYV reference isolate (1). Of the 1,019 samples tested, 471 were positive for CABYV using DAS-ELISA. Some of the positive samples had typical severe yellowing symptoms while symptoms in other samples were masked by mosaic or leaf deformations caused by other viruses frequently found in mixed infections (data not shown). During the entire survey, CABYV was detected by DAS-ELISA in 201 of 503 melon samples, 72 of 129 cucumber samples, 158 of 249 squash samples, and 40 of 138 watermelon samples. These results indicate that CABYV is widely distributed on four cucurbit species in the major growing areas of Iran. In order to confirm CABYV identification, total RNA extracts (TRI-Reagent, Sigma Chemical, St Louis, MO) were obtained from 25 samples that were positive using DAS-ELISA originating from Khorasan (n = 4), Esfahan (n = 6), Teheran (n = 3), Hormozgan (n = 4), Azerbaiejan-E-Sharqi (n = 4), and Kerman (n = 4). Reverse transcription-polymerase chain reactions (RT-PCR) were carried out using forward (5′-CGCGTGGTTGTGG-TCAACCC-3′) and reverse (5′-CCYGCAACCGAGGAAGATCC-3′) primers designed in conserved regions of the coat protein gene according to the sequence of a CABYV reference isolate (3) and three other unpublished CABYV sequences. RT-PCR experiments yielded an expected 479-bp product similar to the fragment amplified with extracts from the reference isolate. No amplification of the product occurred from healthy plant extracts. To our knowledge, this is the first report of the occurrence of CABYV in Iran on various cucurbit species. The high frequency (46.2%) with which CABYV was detected in the samples assayed indicates that this virus is one of the most common virus infecting cucurbits in Iran. References: (1) H. Lecoq et al. Plant Pathol. 41:749, 1992 (2) M. A. Mayo and C. J. D'Arcy. Page 15 in: The Luteoviridae. H. G. Smith and H. Barker, eds. CAB International Mycological Institute, Wallingford, UK, 1999. (3) H. Guilley et al. Virology 202:1012, 1994.

Complete nucleotide sequence of the Iranian strain of tomato yellow leaf curl virus (TYLCV-IR) was determined and compared with some begomoviruses. The complete sequence of TYLCV-IR clustered together with TYLCV and TYLCV-MId from Israel. A similar relationship holds when the deduced amino acid sequences of V1, V2, C2 and C3 and nucleotide sequences of IR, and RIR were compared. In contrast, phylogenetic analyses of amino acid sequences of C4, C1, and nucleotide sequences of LIR revealed that TYLCV-IR clustered with TLCIRV and two Indian species: ToLCBV- [Ban4], and ToLCKV. The phylogenetic analyses, Recombination Detection Program analyses, and sequence alignment survey provided evidence of the occurrence of recombination between an Israeli TYLCV-MId, as major parent, and TLCIRV, as minor parent. In this recombination event, a region (from nt 2149 to 2766) of TYLCV-MId genome were replaced with corresponding genome sequences of TLCIRV (RDP P-value = 5.976 x 10(-72)), which include LIR, C4, and N-terminal of C1. Infectivity of the cloned TYLCV-IR genome was demonstrated by successful agroinoculation of tomato ( Lycopersicon esculentum) and other plant species. The disease was transmitted by the natural vector Bemisia tabaci from agroinoculated plants to test plants, reproducing in this way the full biological cycle and proving that the genome of TYLCV-IR consists of only one circular single-stranded DNA molecule.

International audience; The genomes of two Watermelon chlorotic stunt virus (WmCSV) isolates, one from the Sudan and one from Iran, were cloned and sequenced. Sequence relationship with other geminiviruses characterizes WmCSV as a typical Eastern Hemisphere geminivirus with a bipartite genome. The two geographically distant WmCSV isolates from Africa and the Middle East share a very high overall sequence similarity: 98% between their DNA-A and 96% between their DNA-B components, and their respective capsid proteins are identical. A single amino acid change in the capsid protein (N131D) renders WmCSV whitefly nontransmissible. This region of the capsid is also implicated in transmission by Bemisia tabaci of Tomato yellow leaf curl virus.

An indirect double antibody sandwich enzyme-linked immunosorbent assay (IDAS-ELISA) system using antibodies elicited in rabbits and chickens is described for the detection of alfalfa mosaic virus (AMV). The method is capable of detecting 40 pg of homologous purified AMV and was shown to be suitable for detecting the virus in aphids. AMV in the order of 150 pg was detected in single aphids. It was shown that a significant proportion of insects could acquire this or higher amounts of virus during 1 min probes on the leaves of infected plants. The IDAS-ELISA should find applicability in research on the acquisition of viruses by aphids and in epidemiological studies for detecting viruses in insects from traps.

Several viral diseases are responsible for significant economic losses in commercial cucurbit production worldwide. During a survey conducted in July 2002 in cucurbit growing areas in southern Iran, vein-clearing symptoms and leaf chlorosis on older leaves were observed on a cucumber plant near Jiroft (Kerman Province). These symptoms were similar to those caused by Cucumber vein yellowing virus (CVYV, genus Ipomovirus, family Potyviridae), a virus first described in Israel (1) and now widespread in cucurbit crops in the Middle East and Mediterranean Regions (2). The identification of CVYV was established through differential host range reaction and immunosorbent electron microscopy (IEM) experiments. Typical vein-clearing symptoms were observed following mechanical inoculation of cucumber and melon plantlets, but no symptoms were observed in Chenopodium quinoa, C. amaranticolor, Nicotiana tabacum, or Vigna sinensis. Numerous, slightly flexuous, elongated virus particles were observed in infected plant extracts. The particles were decorated by a polyclonal antiserum raised against a Sudanese isolate of CVYV. To confirm CVYV identification, total RNA extracts (TRI-Reagent, Sigma Chemical, St. Louis, MO) were obtained from the original cucumber sample. Reverse transcription-polymerase chain reactions (RT-PCR) were carried out using CVYV-specific primers CVYV-CP-5′: 5′-GCTTCTGGTTCTCAAGTGGA-3′ and CVYV-CP-3′: 5′-GATGCATCAGTTGTCAGATG-3′ designed according to the partial sequence of the coat protein gene of CVYV-Isr (GenBank Accession No. AF233429) (2). A 540-bp fragment corresponding to the central region of CVYV coat protein was obtained from extracts of infected plants but not from healthy plant extracts. Additional watermelon (n = 6) and melon (n = 4) leaf samples collected from plants growing in the same farm were tested for the presence of CVYV using RT-PCR. All samples reacted positively for CVYV. However, a sample of Citrullus colocynthis, a wild relative of watermelon growing nearby, was negative. CVYV was not detected using RT-PCR in 123 additional cucurbit samples collected from the eastern and central regions of Iran during a survey conducted in 2002. To our knowledge, this is the first report of the occurrence of CVYV in Iran. Additional surveys in southern regions where Bemisia tabaci, the vector of CVYV, is abundant are required to better estimate the prevalence of this virus in cucurbit crops in Iran. References: (1) S. Cohen and F. E. Nitzany. Phytopathol. Mediterr. 1:44, 1960 (2) H. Lecoq et al. J. Gen. Virol. 81:2289, 2000.

During 2001, a survey was conducted in vineyards in northwestern Iran and the eastern and western provinces of Azarbaijan, Zanjan, and Qazvin to detect the presence of Arabis mosaic virus (ArMV) and Grapevine leaf roll associated virus-3 (GLRaV-3). From December 2001 through March 2002, 5,352 dormant stem cuttings were collected. A portion of all stem cuttings was callused, rooted, potted, and grown in a greenhouse. Each sample was tested for the presence of ArMV and GLRaV-3 with specific antisera (Bioreba, Basel, Switzerland). Extracts of bark scrapings were prepared from the remaining portion of the dormant cuttings. After bud break of rooted cuttings, leaf extracts were prepared by the method used by Rowhani et al. (2). Dormant bark and leaf extracts were used with double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Among the samples tested, ArMV and GLRaV-3 were found in 4.7 and 2.3% of the collection, respectively. Leaf extracts that had tested positive for ArMV using ELISA, were mechanically inoculated on the indicator host plants of Chenopodium amaranticolor, Cucumis sativus, and Petunia × hybrida. All plants developed local lesions that subsequently developed systemic chlorosis that is reported for ArMV. Biological assays confirmed the results of ArMV using ELISA. To confirm testing, a number of the samples that were found positive for GLRaV-3 in ELISA tests were tested by reverse transcription-polymerase chain reaction (RT-PCR) technique using previously described specific primers (1). The PCR reaction resulted in the specifically amplification of a 300-bp fragment of GLRaV-3 RNA. In cvs. White Keshmesh, Ghezel Ozum, Red Lal, Askari, and Red Kehsmesh, symptoms associated with GLRaV-3 were reduced growth with smaller leaves and shoots. By late summer, the leaves rolled downward and the interveinal areas of the leaves turned to red, while the principal veins remained green in cvs. Red Lal and Red Keshmesh. Symptoms associated with ArMV were reduced growth, shoots with short internodes, and leaf chlorosis and distortion. To our knowledge, this is the first report of ArMV and GLRaV-3 from grapevines in Iran. References: (1) A. Nassuth et al. J. Virol. Methods 90:37, 2000. (2) A. Rowhani et al. Plant Dis. 81:799, 1997.

Severe leaf and stem necrosis before flowering was observed in potato (Solanum tuberosum) fields of Firouzkoh Province, Iran, during the summer of 1998. Infected plants died before the end of the growing season. Necrosis was more severe in cv. Agria than in cvs. Ajaxs and Arinda. A high population of Thrips tabaci was observed in August and September. Tomato spotted wilt virus (TSWV) (1) was detected in affected potatoes by using specific TSWV-IgG (from Bioreba) in double-antibody sandwich enzyme linked immunosorbent assay and by indicator plant reactions. Mechanical inoculation of indicator plants with leaf extracts of symptomatic potatoes produce necrotic local lesions in Chenopodium quinoa, C. amaranticolor, Gomphrena globosa, Vicia faba, Vigna sinensis, Phaseolus aureus var. Gohar, P. vulgaris, and Petunia hybrida. The virus caused systemic necrosis in Capsicum frutescens, Datura stramonium, D. metel, Nicotiana glutinosa, N. rustica, and Trapaeolum majus, preceded by systemic chlorotic spots. TSWV was reported from ornamental crops in Tehran and Absard areas near to Firouzkoh province (2), but this is the first report of TSWV occurrence on potatoes in Iran. References: (1) T. S. Ie. Descriptions of Plant Viruses. No. 39, 1970. (2) A. A. Moeini, et al. Iran. J. Plant Pathol. (In press.)