New World Cactaceae Plants Harbor Diverse Geminiviruses.

The family Cactaceae comprises a diverse group of typically succulent plants that are native to the American continent but have been introduced to nearly all other continents, predominantly for ornamental purposes. Despite their economic, cultural, and ecological importance, very little research has been conducted on the viral community that infects them. We previously identified a highly divergent geminivirus that is the first known to infect cacti. Recent research efforts in non-cultivated and asymptomatic plants have shown that the diversity of this viral family has been under-sampled. As a consequence, little is known about the effects and interactions of geminiviruses in many plants, such as cacti. With the objective to expand knowledge on the diversity of geminiviruses infecting cacti, we used previously acquired high-throughput sequencing results to search for viral sequences using BLASTx against a viral RefSeq protein database. We identified two additional sequences with similarity to geminiviruses, for which we designed abutting primers and recovered full-length genomes. From 42 cacti and five scale insects, we derived 42 complete genome sequences of a novel geminivirus species that we have tentatively named Opuntia virus 2 (OpV2) and 32 genomes of an Opuntia-infecting becurtovirus (which is a new strain of the spinach curly top Arizona virus species). Interspecies recombination analysis of the OpV2 group revealed several recombinant regions, in some cases spanning half of the genome. Phylogenetic analysis demonstrated that OpV2 is a novel geminivirus more closely related to viruses of the genus Curtovirus, which was further supported by the detection of three recombination events between curtoviruses and OpV2. Both OpV2 and Opuntia becurtoviruses were identified in mixed infections, which also included the previously characterized Opuntia virus 1. Viral quantification of the co-infected cactus plants compared with single infections did not show any clear trend in viral dynamics that might be associated with the mixed infections. Using experimental Rhizobium-mediated inoculations, we found that the initial accumulation of OpV2 is facilitated by co-infection with OpV1. This study shows that the diversity of geminiviruses that infect cacti is under-sampled and that cacti harbor diverse geminiviruses. The detection of the Opuntia becurtoviruses suggests spill-over events between viruses of cultivated species and native vegetation. The threat this poses to cacti needs to be further investigated.

Phytosanitary Interventions for Safe Global Germplasm Exchange and the Prevention of Transboundary Pest Spread: The Role of CGIAR Germplasm Health Units.

The inherent ability of seeds (orthodox, intermediate, and recalcitrant seeds and vegetative propagules) to serve as carriers of pests and pathogens (hereafter referred to as pests) and the risk of transboundary spread along with the seed movement present a high-risk factor for international germplasm distribution activities. Quarantine and phytosanitary procedures have been established by many countries around the world to minimize seed-borne pest spread by screening export and import consignments of germplasm. The effectiveness of these time-consuming and cost-intensive procedures depends on the knowledge of pest distribution, availability of diagnostic tools for seed health testing, qualified operators, procedures for inspection, and seed phytosanitation. This review describes a unique multidisciplinary approach used by the CGIAR Germplasm Health Units (GHUs) in ensuring phytosanitary protection for the safe conservation and global movement of germplasm from the 11 CGIAR genebanks and breeding programs that acquire and distribute germplasm to and from all parts of the world for agricultural research and food security. We also present the challenges, lessons learned, and recommendations stemming from the experience of GHUs, which collaborate with the national quarantine systems to export and distribute about 100,000 germplasm samples annually to partners located in about 90 to 100 countries. Furthermore, we describe how GHUs adjust their procedures to stay in alignment with evolving phytosanitary regulations and pest risk scenarios. In conclusion, we state the benefits of globally coordinated phytosanitary networks for the prevention of the intercontinental spread of pests that are transmissible through plant propagation materials.

Genetic diversity and recombination between turnip yellows virus strains in Australia.

Disease outbreaks caused by turnip yellows virus (TuYV), a member of the genus Polerovirus, family Luteoviridae, regularly occur in canola and pulse crops throughout Australia. To understand the genetic diversity of TuYV for resistance breeding and management, genome sequences of 28 TuYV isolates from different hosts and locations were determined using high-throughput sequencing (HTS). We aimed to identify the parts of the genome that were most variable and clarify the taxonomy of viruses related to TuYV. Poleroviruses contain seven open reading frames (ORFs): ORF 0-2, 3a, and 3-5. Phylogenetic analysis based on the genome sequences, including isolates of TuYV and brassica yellows virus (BrYV) from the GenBank database, showed that most genetic variation among isolates occurred in ORF 5, followed by ORF 0 and ORF 3a. Phylogenetic analysis of ORF 5 revealed three TuYV groups; P5 group 1 and group 3 shared 45-49% amino acid sequence identity, and group 2 is a recombinant between the other two. Phylogenomic analysis of the concatenated ORFs showed that TuYV is paraphyletic with respect to BrYV, and together these taxa form a well-supported monophyletic group. Our results support the hypothesis that TuYV and BrYV belong to the same species and that the phylogenetic topologies of ORF 0, 3a and 5 are incongruent and may not be informative for species demarcation. A number of beet western yellow virus (BWYV)- and TuYV-associated RNAs (aRNA) were also identified by HTS for the first time in Australia.

A Novel Divergent Geminivirus Identified in Asymptomatic New World Cactaceae Plants.

Cactaceae comprise a diverse and iconic group of flowering plants which are almost exclusively indigenous to the New World. The wide variety of growth forms found amongst the cacti have led to the trafficking of many species throughout the world as ornamentals. Despite the evolution and physiological properties of these plants having been extensively studied, little research has focused on cactus-associated viral communities. While only single-stranded RNA viruses had ever been reported in cacti, here we report the discovery of cactus-infecting single-stranded DNA viruses. These viruses all apparently belong to a single divergent species of the family Geminiviridae and have been tentatively named Opuntia virus 1 (OpV1). A total of 79 apparently complete OpV1 genomes were recovered from 31 different cactus plants (belonging to 20 different cactus species from both the Cactoideae and Opuntioideae clades) and from nine cactus-feeding cochineal insects (Dactylopius sp.) sampled in the USA and Mexico. These 79 OpV1 genomes all share > 78.4% nucleotide identity with one another and < 64.9% identity with previously characterized geminiviruses. Collectively, the OpV1 genomes display evidence of frequent recombination, with some genomes displaying up to five recombinant regions. In one case, recombinant regions span ~40% of the genome. We demonstrate that an infectious clone of an OpV1 genome can replicate in Nicotiana benthamiana and Opuntia microdasys. In addition to expanding the inventory of viruses that are known to infect cacti, the OpV1 group is so distantly related to other known geminiviruses that it likely represents a new geminivirus genus. It remains to be determined whether, like its cactus hosts, its geographical distribution spans the globe.

Viruses representing two new genomovirus species identified in citrus from Tunisia.

Using a high-throughput sequencing approach, we identified four genomoviruses (family Genomoviridae) associated with a sweet orange (Citrus sinensis) plant collected in Tunisia. The ssDNA genomes of these genomoviruses, which were amplified, cloned and Sanger sequenced, range in size from 2156 to 2191 nt. Three of these viruses share > 99% full-genome pairwise sequence identity and are referred to as citrus Tunisia genomovirus 1 (CTNGmV-1). The CTNGmV-1 isolates share < 62% genome-wide pairwise nucleotide sequence identity with other genomoviruses and belong to the genus Gemykolovirus. The genome of the fourth virus, which was called CTNGmV-2, shares < 68% nucleotide sequence identity with other genomoviruses and belongs to the genus Gemycircularvirus. Based on the species demarcation criteria for members of the family Genomoviridae, CTNGmV-1 and -2 would each represent a new species. Although found associated with Citrus sp. plants, it is likely that these viruses infect fungi or other organisms associated with the plants.

The Westward Journey of Alfalfa Leaf Curl Virus.

Alfalfa leaf curl virus (ALCV), which causes severe disease symptoms in alfalfa (Medicago sativa L.) and is transmitted by the widespread aphid species, Aphis craccivora Koch, has been found throughout the Mediterranean basin as well as in Iran and Argentina. Here we reconstruct the evolutionary history of ALCV and attempt to determine whether the recent discovery and widespread detection of ALCV is attributable either to past diagnostic biases or to the emergence and global spread of the virus over the past few years. One hundred and twenty ALCV complete genome sequences recovered from ten countries were analyzed and four ALCV genotypes (ALCV-A, ALCV-B, ALCV-C, and ALCV-D) were clearly distinguished. We further confirm that ALCV isolates are highly recombinogenic and that recombination has been a major determinant in the origins of the various genotypes. Collectively, the sequence data support the hypothesis that, of all the analyzed locations, ALCV likely emerged and diversified in the Middle East before spreading to the western Mediterranean basin and Argentina.

Molecular characterization of faba bean necrotic yellows viruses in Tunisia.

Faba bean necrotic yellows virus (FBNYV) (genus Nanovirus; family Nanoviridae) has a genome comprising eight individually encapsidated circular single-stranded DNA components. It has frequently been found infecting faba bean (Vicia faba L.) and chickpea (Cicer arietinum L.) in association with satellite molecules (alphasatellites). Genome sequences of FBNYV from Azerbaijan, Egypt, Iran, Morocco, Spain and Syria have been determined previously and we now report the first five genome sequences of FBNYV and associated alphasatellites from faba bean sampled in Tunisia. In addition, we have determined the genome sequences of two additional FBNYV isolates from chickpea plants sampled in Syria and Iran. All individual FBNYV genome component sequences that were determined here share > 84% nucleotide sequence identity with FBNYV sequences available in public databases, with the DNA-M component displaying the highest degree of diversity. As with other studied nanoviruses, recombination and genome component reassortment occurs frequently both between FBNYV genomes and between genomes of nanoviruses belonging to other species.

Molecular diversity of Chickpea chlorotic dwarf virus in Sudan: high rates of intra-species recombination - a driving force in the emergence of new strains.

In Sudan Chickpea chlorotic dwarf virus (CpCDV, genus Mastrevirus, family Geminiviridae) is an important pathogen of pulses that are grown both for local consumption, and for export. Although a few studies have characterised CpCDV genomes from countries in the Middle East, Africa and the Indian subcontinent, little is known about CpCDV diversity in any of the major chickpea production areas in these regions. Here we analyse the diversity of 146 CpCDV isolates characterised from pulses collected across the chickpea growing regions of Sudan. Although we find that seven of the twelve known CpCDV strains are present within the country, strain CpCDV-H alone accounted for ∼73% of the infections analysed. Additionally we identified four new strains (CpCDV-M, -N, -O and -P) and show that recombination has played a significant role in the diversification of CpCDV, at least in this region. Accounting for observed recombination events, we use the large amounts of data generated here to compare patterns of natural selection within protein coding regions of CpCDV and other dicot-infecting mastrevirus species.

Control of plant virus diseases in cool-season grain legume crops.

Cool-season grain legume crops become infected with a wide range of viruses, many of which cause serious diseases and major yield losses. This review starts by discussing which viruses are important in the principal cool-season grain legume crops in different parts of the world, the losses they cause and their economic impacts in relation to control. It then describes the main types of control measures available: host resistance, phytosanitary measures, cultural measures, chemical control, and biological control. Examples are provided of successful deployment of the different types of measures to control virus epidemics in cool-season grain legume crops. Next it emphasizes the need for integrated approaches to control because single control measures used alone rarely suffice to adequately reduce virus-induced yield losses in these crops. Development of effective integrated disease management (IDM) strategies depends on an interdisciplinary team approach to (i) understand the ecological and climatic factors which lead to damaging virus epidemics and (ii) evaluate the effectiveness of individual control measures. In addition to using virus-resistant cultivars, other IDM components include sowing virus-tested seed stocks, selecting cultivars with low seed transmission rates, using diverse phytosanitary or cultural practices that minimize the virus source or reduce its spread, and using selective pesticides in an environmentally responsible way. The review finishes by briefly discussing the implications of climate change in increasing problems associated with control and the opportunities to control virus diseases more effectively through new technologies.

Evidence that dicot-infecting mastreviruses are particularly prone to inter-species recombination and have likely been circulating in Australia for longer than in Africa and the Middle East.

Viruses of the genus Mastrevirus (family Geminiviridae) are transmitted by leafhoppers and infect either mono- or dicotyledonous plants. Here we have determined the full length sequences of 49 dicot-infecting mastrevirus isolates sampled in Australia, Eritrea, India, Iran, Pakistan, Syria, Turkey and Yemen. Comprehensive analysis of all available dicot-infecting mastrevirus sequences showed the diversity of these viruses in Australia to be greater than in the rest of their known range, consistent with earlier studies, and that, in contrast with the situation in monocot-infecting mastreviruses, detected inter-species recombination events outnumbered intra-species recombination events. Consistent with Australia having the greatest diversity of known dicot-infecting mastreviruses phylogeographic analyses indicating the most plausible scheme for the spread of these viruses to their present locations, suggest that most recent common ancestor of these viruses is likely nearer Australia than it is to the other regions investigated.

Virus diseases of peas, beans, and faba bean in the Mediterranean region.

In the Mediterranean region, pea, bean, and faba bean production is affected by around 17 major viruses. These viruses do not have the same ecology and consequently require a variety of different preventive measures to control them. Some of these viruses have a narrow host range, such as Faba bean necrotic yellows virus (FBNYV), and others, such as Alfalfa mosaic virus (AMV) and Cucumber mosaic virus (CMV), a very wide host range. Such features are important when identifying sources of virus inoculum in a region, and the vectors can transmit viruses from natural reservoirs to the crop plants. Some of these viruses are seed borne and, consequently, can be disseminated long distances through infected seeds. Crop losses caused by these viruses are variable, depending on the sensitivity and susceptibility of the crop to infection. Host resistance genes have been identified for some of these viruses, but in others, such as FBNYV, no resistance genes in faba bean have been identified yet. Significant progress was made in developing precise methods for the identification of these viruses, and new virus problems are being identified every year. This chapter is not intended to be a review for pea, bean, and faba bean viruses, but rather focuses on the major viruses which affect these crops in the Mediterranean basin with focus on the progress made over the past two decades.

Analysis of the sequence of a dicot-infecting mastrevirus (family Geminiviridae) originating from Syria.

Chickpea stunt disease (CSD) across southern Asia, the Middle East and North Africa is caused by a number of viruses that include single-stranded DNA viruses of the genus Mastrevirus (family Geminiviridae). Despite the importance of CSD in reducing chickpea and lentil production, until recently little was known of the nature of the pathogens causing the disease. Sequence characterisation of virus isolates from Sudan and Pakistan showed the viruses concerned to potentially be new mastrevirus species related to Bean yellow dwarf virus (BeYDV), a virus known to occur in both southern Africa and southern Asia. Here we have determined the complete nucleotide sequence of a mastrevirus associated with CSD in Syria. This virus represents a proposed new species, closely related to the recently characterised Chickpea chlorotic dwarf Sudan virus and Chickpea chlorotic dwarf Pakistan virus but with the highest sequence identity to BeYDV, for which we propose the name Chickpea chlorotic dwarf Syria virus. In addition the biological integrity of the clone was confirmed by infection of Nicotiana benthamiana plants using Agrobacterium-mediated inoculation.

Epidemiology and integrated management of persistently transmitted aphid-borne viruses of legume and cereal crops in West Asia and North Africa.

Cool-season food legumes (faba bean, lentil, chickpea and pea) and cereals (bread and durum wheat and barley) are the most important and widely cultivated crops in West Asia and North Africa (WANA), where they are the main source of carbohydrates and protein for the majority of the population. Persistently transmitted aphid-borne viruses pose a significant limitation to legume and cereal production worldwide. Surveys conducted in many countries in WANA during the last three decades established that the most important of these viruses are: Faba bean necrotic yellows virus (FBNYV: genus Nanovirus; family Nanoviridae), Bean leafroll virus (BLRV: genus Luteovirus; family Luteoviridae), Beet western yellows virus (BWYV: genus Polerovirus; family Luteoviridae), Soybean dwarf virus (SbDV: genus Luteovirus; family Luteoviridae) and Chickpea chlorotic stunt virus (CpCSV: genus Polerovirus; family Luteoviridae) which affect legume crops, and Barley yellow dwarf virus-PAV (BYDV-PAV: genus Luteovirus; family Luteoviridae), Barley yellow dwarf virus-MAV (BYDV-MAV: genus Luteovirus; family Luteoviridae) and Cereal yellow dwarf virus-RPV (CYDV-RPV: genus Polerovirus; family Luteoviridae) which affect cereal crops. Loss in yield caused by these viruses is usually high when infection occurs early in the growing season. Many aphid vector species for the above-mentioned viruses are reported to be prevalent in the WANA region. In addition, in this region many wild species (annual or perennial) were found infected with these viruses and may play an important role in their ecology and spread. Fast spread of these diseases was always associated with high aphid vector populations and activity. Although virus disease management can be achieved by combining several control measures, development of resistant genotypes is undoubtedly one of the most appropriate control methods. Over the last three decades barley and wheat genotypes resistant to BYDV, faba bean genotypes resistant to BLRV, and lentil genotypes resistant to BLRV, FBNYV and SbDV have been successfully identified. Moreover, progress has been made in disease management of some of these viruses using a combination of management options. Experience gathered over the last few decades clearly showed that no single method of virus disease control suffices to reduce yield losses in legume and cereal crops.

First Record of Barley yellow striate mosaic virus Affecting Wheat Summer-Nurseries in Syria.

A limited survey to identify virus diseases affecting wheat in summer nurseries in agricultural stations in southern Syria was conducted during October 2002. A total of 94 bread and durum wheat samples with symptoms suggestive of virus infection (stripping, stunting, and yellowing) were collected. All samples were tested for the presence of four viruses by tissue-blot immunoassay (2) at the Virology Laboratory of ICARDA, Aleppo, Syria using the following polyclonal antibodies: Barley stripe mosaic virus (BSMV); Barley yellow dwarf virus-PAV (BYDV-PAV) and Wheat streak mosaic virus (WSMV) from the Virology Laboratory at ICARDA; and Barley yellow striate mosaic virus (BYSMV) isolated from Italy (BYSMV-Italy) and provided by M. Conti, Instituto di Fitovirologia applicata, Turino, Italy. Serological results obtained indicated that BYSMV was the most commonly encountered virus (78.7%) followed by BYDV-PAV (22.3%), whereas, BSMV and WSMV were not detected in any of the samples tested. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by western blots, purified BYSMV preparations were observed to contain a 47-kDa structural protein typical of the N protein of Rhabdoviruses that reacted strongly with three BYSMV antisera (BYSMV-Italy, BYSMV-Lebanon [4], and BYSMV-Morocco [1]). Samples that reacted with BYSMV antisera were transmitted from wheat to wheat, barley, and oat plants by the planthopper Laodelphax striatella (Fallen) (Hemiptera: family Delphacidae) in a persistent manner, and the major symptoms of BYSMV on cereal crops were stripping and stunting. BYDV-PAV has been reported from Syria earlier (3) but to our knowledge, this is the first report of BYSMV affecting wheat in Syria. References: (1) B. E. Lockhart et al. Plant Dis. 70:1113, 1986. (2) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994. (3) K. M. Makkouk et al. Phytopathol. Mediterr. 28:164, 1989. (4) K. M. Makkouk et al. Plant Dis. 85:446, 2001.

A Survey of Viruses Affecting Faba Bean (Vicia faba) in Tunisia Includes First Record of Soybean dwarf virus.

A survey was conducted in April 2003 to identify viruses infecting faba bean (Vicia faba L.) in six regions (Beja, Bizerte, Cap-bon, Le Kef, Siliana, and Zaghouan) in Tunisia. A total of 292 faba bean samples with symptoms of viral infection (leaf rolling, yellowing, and mosaic) were collected. The samples were tested at the virology laboratory of the International Center for Agricultural Research in the Dry Areas (ICARDA), Syria, for 11 viruses using the tissue-blot immunoassay procedure (3). Specific rabbit polyclonal antisera were used to test for Chickpea chlorotic dwarf virus (CpCDV) (provided by H. J. Vetten, BBA, Braunschweig, Germany), Alfalfa mosaic virus (AMV), Bean yellow mosaic virus (BYMV), Broad bean mottle virus (BBMV), Broad bean stain virus (BBSV), Cucumber mosaic virus (CMV), and Pea seedborne mosaic virus (PSbMV) (ICARDA, Aleppo, Syria). In addition, four specific monoclonal antibodies were used to detect Bean leaf roll virus (BLRV) (4B10) (2), Beet western yellows virus (BWYV) (ATCC PVAS-647; American Type Culture Collection, Manassas, VA), Faba bean necrotic yellows virus (FBNYV) (3-2E9) (1), and Soybean dwarf virus (SbDV) (ATCC PVAS-650). Serological tests showed that BBMV, a beetle-transmitted and seedborne virus identified in 23.3% (68 samples) of the samples tested, was the most common. BLRV, FBNYV, BWYV, BYMV, SbDV, and PSbMV were detected in 56, 33, 31, 10, 5, and 1 sample(s) of 292 samples tested, respectively. AMV, BBSV, CMV, and CpCDV were not detected in any samples tested. In Tunisia, BLRV, BWYV, BYMV, FBNYV, and PSbMV have previously been reported in faba bean (4), but to our knowledge, this is the first record of SbDV affecting faba bean in Tunisia, where it was detected in two fields in the Cap-bon Region. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by western blots, extracts from SbDV-infected plants were observed to contain 23-kDa structural proteins, which reacted strongly with SbDV monoclonal antibodies. Transmission tests showed that the samples, which reacted with SbDV monoclonal antibodies, were transmitted to faba bean plants by the pea aphid (Acyrthosiphon pisum Harris) in a persistent manner. To our knowledge, this is the first report of SbDV naturally infecting faba bean in Tunisia and it could cause a serious problem to other leguminous crops grown in Tunisia, such as French bean and peas, which are hosts for the virus. References: (1) A. Franz and K. M. Makkouk Ann. Appl. Biol. 128:255, 1996. (2) L. Katul. Characterization by serology and molecular biology of bean leaf roll virus and faba bean necrotic yellows virus. PhD thesis. University of Gottingen, Gottingen, Germany, 1992. (3) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994. (4) A. Najar et al. Phytopathol. Mediterr. 39:423, 2000.

First Record of Faba bean necrotic yellows virus and Beet western yellows virus Infecting Faba Bean in Tunisia.

A survey was conducted in April 2000 to identify viruses infecting faba bean (Vicia faba L.) in seven regions (Beja, Bizerte, Cap-bon, Jendouba, Kairouan, Siliana, and Zaghouan) of Tunisia. Around 4,000 random samples were collected from 34 fields (100 to 200 samples per field). Samples were tested by tissue-blot immunoassay procedure (2) at the Virology Laboratory of INRAT for the presence of 14 different viruses. All antisera used were specific, including those for Faba bean necrotic yellows virus (FBNYV) (1) and Beet western yellows virus (BWYV) (ATCC-PVAS-647). Broad bean mottle, a beetle-transmitted and seedborne virus, was the most abundant with an average incidence of 2.3%. The highest disease incidence occurred with BWYV, which was in 20 and FBNYV in 4 of 98 random samples from a field in the Siliana region; and with BWYV in 7 and BBMV in 21 of 120 samples from a field in the Jendouba region. Other viruses such as broad bean stain, cucumber mosaic, and bean leaf roll were detected rarely (<1%). This is the first record of FBNYV and BWYV infecting faba bean in Tunisia. BWYV was detected in 1.2% of the samples tested collected from 20 fields comprising all seven regions. FBNYV was detected in 0.9% of the samples tested collected from 13 fields comprising all except the Capbon region. References: (1) A. Franz et al. Ann. Appl. Biol. 128:255, 1996. (2) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994.

First Report of Pea Enation Mosaic Virus Affecting Lentil (Lens culinaris) in Syria.

Symptoms suggestive of virus infection in lentil (Lens culinaris Medik.) fields in Dara'a in southern Syria have been observed, in epidemic proportions, almost annually since 1994. A similar epidemic was observed on many lentil genotypes at the ICARDA farm, near Aleppo, as well as in other locations in northern Syria during 1998. Symptoms included growth reduction and rolling of leaves, accompanied by mottling with tip wilting or necrosis. Field symptoms were reproduced on lentil cv. Syrian Local upon mechanical inoculation of plants with inoculum from symptomatic field plants. Transmission tests showed that the disease agent can be transmitted from lentil to lentil, pea (Pisum sativum L.), and faba bean (Vicia faba L.) plants by the pea aphid (Acyrthosiphon pisum Harris) in a persistent manner. More than 500 symptomatic lentil plants were collected and tested for the presence of 14 different viruses by the tissue-blot immunoassay (TBIA) (2). Around 80% of the samples reacted only with antiserum to pea enation mosaic virus (PEMV), a Dutch isolate (E1540) provided by L. Bos, Wageningen, The Netherlands (1). Surveys conducted during the 1997/1998 growing season showed that PEMV was widely distributed in the major lentil-growing areas of Syria: some lentil fields had more than 50% virus incidence. This is the first record of PEMV naturally infecting lentil in Syria. References: (1) K. Mahmood and D. Peters. Neth. J. Plant Pathol. 79:138, 1973. (2) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994.