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Chickpea plants with severe yellowing and tip wilting were observed in the Cap-Bon Region of Tunisia in 2006. The viral-like symptoms resulted in yield loss of approximately 25% in some fields. A total of 110 symptomatic chickpea plants was collected from nine chickpea fields and tested at the Virology Laboratory of ICARDA, Syria for eight legume viruses using tissue-blot immunoassay (TBIA) (3). Polyclonal antisera produced at the ICARDA Virology Laboratory were used to test for Chickpea chlorotic dwarf virus (genus Mastrevirus, family Geminiviridae), Broad bean stain virus (genus Comovirus, family Secoviridae), Broad bean mottle virus (genus Bromovirus, family Bromoviridae), and Bean yellow mosaic virus and Pea seed borne mosaic virus (genus Potyvirus, family Potyviridae). Antiserum to Beet mosaic virus (BtMV; genus Potyvirus, family Potyviridae) (AS-0143) was provided by the German Collection of Microorganisms and Cell Cultures (DSMZ, Braunschweig, Germany). In addition, three monoclonal antibodies (MAb) were used to detect Faba bean necrotic yellows virus (FBNYV; genus Nanovirus, family Nanoviridae) (MAb 3-2E9) (1), potyviruses (PVAS-769 [MAb PTY 3 Potyvirus Group] American Type Culture Collection, Manassas, VA), and luteoviruses (MAb B-2-5G4) (2). Twenty-two of the plants tested positive with MAb PTY 3 and BtMV antisera, 56 samples reacted with MAb B-2-5G4, and eight plants with the FBNYV MAb, whereas 24 plants tested negative with all antisera. Because reactions with the BtMV antiserum were unexpected, detection of BtMV was confirmed by reverse transcription-(RT)-PCR assays using BtMV-specific primers (LN26 and LN27) (4), which produced an amplicon of expected size (1,050 bp) from all plants that reacted with BtMV antiserum but not from plants that were serologically negative. Leaf tissue from a BtMV-infected plant was ground in 0.01 M potassium phosphate buffer, pH 7.2 (1:20, wt/vol), mixed with 0.5% celite, and used for mechanical inoculation of chickpea seedlings (cv. Beja 4). In addition, adults of three legume aphid species (Aphis craccivora, A. fabae, and Acyrthosiphon pisum) were starved for 1 h before feeding on BtMV-infected chickpea leaves for an acquisition access period of 5 min. Fifteen aphids of each species were placed on each chickpea plant, allowed to feed for 24 h, and then sprayed with an insecticide. Tip wilting symptoms appeared on plants 15 to 20 days after mechanical and aphid inoculations but not on plants used as negative control treatments (inoculated mechanically with healthy leaf tissue or with aphids that had fed on noninfected chickpea plants). Use of BtMV antiserum for TBIA analysis of inoculated plants revealed systemic BtMV infections in 35 of 92 plants inoculated mechanically and 15 of 75 plants inoculated with viruliferous A. fabae only. To our knowledge, this is the first record of BtMV infecting chickpea in Tunisia. References: (1) A. Franz et al. 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. Ph.D. thesis. University of Gottingen, Germany, 1992. (3) K. M. Makkouk and A. Comeau. Eur. J. Plant Pathol. 100:71, 1994. (4) L. G. Nemchinov et al. Arch. Virol. 149:1201, 2004.

A virus isolate from an eggplant (Solanum melongena) showing a mild leaf mosaic had slightly curved filamentous particles with a normal length of 653 nm, a capsid protein size of about 32 kDa and a narrow host range restricted largely to the Solanaceae, It was transmitted by the whitefly Bemisia tabaci in a nonpersistent manner but not by the aphid Mvzus persicae. Its particle morphology, vector transmission and strong reactions in immunoelectron microscopic (IEM) decoration tests with antisera to cowpea mild mottle virus (CPMMV) indicated that it is a CPMMV isolate. Particles of the isolate were weakly decorated when antisera to two carlaviruses, carnation latent virus and a distinct but incompletely described carlavirus from Helleborus, were used in I EM but not with 19 antisera to other carlaviruses. When the isolate was compared in host range and serological properties with another CPMMV isolate from tomato in Israel and two legume isolates of CPMMV, the two isolates originating from the solanaceous hosts in Jordan and Israel appeared to be very similar but clearly distinct from the two legume isolates from India and West Africa. In IEM decoration experiments, a legume isolate of CPMMV from Brazil was serologically distantly related to the two other legume isolates but strikingly dissimilar to the Jordanian isolate. Moreover, the isolates from Jordan and Israel differed from the legume isolates by inducing only banded or nonbanded virion aggregates but no brush-like virion aggregates reported to be characteristic of legume isolates of CPMMV from Africa, Thailand and Brazil. Under the conditions of the present study brush-like inclusiotis were also found with the Indiati and West African isolates. The incidence of the virus was higher in the autumn than spring growing season. Solanum incanum was identified as a possible perennial reservoir of CPMMV during the summer when the Jordan valley is virtually free from cultivated eggplants Zusammenfassung Von Auberginen (Solanum melongena) mit mildem Blattmosaik wurde ein Virus isoliert, welches leicht gebogene filamentose Partikeln mit einer Normallange von 653 nm, ein Kapsidprotein mit einer Molekularmasse von ≊ 32 kDa und einen bauptsachlich auf Solanaceen begrenzten engen Wirtskreis aufwies. Das Virus wurde in nicht-persistenter Weise durch die weise Fliege Bemisia tabaciubertragen, jedoch nicht durch die Blattlaus Myzus persicae. Die Partikelmorphologie, die Vektorubertragung und starke Reaktionen im immunelektronenmikroskopischen (IEM) Dekorationstest mit Antiseren gegen cowpea mild mottle virus (CPMMV) erwiesen das Virus als Isolat CPMMV. Die Partikel des Isolates wurden nur schwach von Antiseren gegen zwei andere Carlaviren, namlich carnation latent virus und ein davon verschiedenes, jedoch unvollstandig charakterisiertes Carlavirus von Helleborus, dekoriert, jedoch nicht von 19 Antiseren gegen andere Carlaviren. Vergleiche der Wirtskreise und der serologischen Eigenschaften des Isolates mit denen eines CPMMV-Isolates von Tomate aus Israel und zweier CPMMV-Isolate von Leguminosen ergaben, das die Isolate von Solanaceen aus Jordanien und Israel einander stark ahneln, jedoch beide klar von den Leguminosenisolaten aus Indien und Westafrika verschieden sind. Ein Leguminosenisolat des CPMMV aus Brasilien war serologisch mit den zwei anderen Leguminosenisolaten entfernt verwandt, jedoch mit den jordanischen und dem israelischen Solanaceenisolaten noch erheblich entfernter. Daruber hinaus unterschieden sich die Isolate aus Jordanien und Israel von den Leguminosenisolaten dadurch, das sie gebanderte bzw. Bundelartige Virusaggregate in infizierten Zellen induzierten, jedoch keine pinselartigen Aggregate wie sie als charakteristisch fur die Leguminosenisolate aus Afrika, Thailand und Brasilien bekannt waren und unter unseren Bedingungen fur die Isolate aus Westafrika und Indien bestatigt wurden. Die Virusbefallsrate war in Jordanien im Herbst hoher als in der Fruhjahrssaison. Solanum incanum wurde fur die Sommerzeit, wenn im Jordantal keine Auberginen angebaut warden, als mogliches Uberdauerungsreservoir des CPMMV identifiziert.

Sweet potato virus disease (SPVD) is the name used to describe a range of severe symptoms in different cultivars of sweet potato, comprising overall plant stunting combined with leaf narrowing and distortion, and chlorosis, mosaic or vein-clearing. Affected plants of various cultivars were collected from several regions of Uganda. All samples contained the aphid-borne sweet potato feathery mottle potyvirus (SPFMV) and almost all contained the whitefly-borne sweet potato chlorotic stunt closterovirus (SPCSV). SPCSV was detected by a mix of monoclonal antibodies (MAb) previously shown to react only to a Kenyan isolate of SPCSV, but not by a mixture of MAb that detected SPCSV isolates from Nigeria and other countries. Sweet potato chlorotic fleck virus (SPCFV) and sweet potato mild mottle ipomovirus (SPMMV) were seldom detected in SPVD-affected plants, while sweet potato latent virus (SPLV) was never detected. Isolates of SPFMV and SPCSV obtained by insect transmissions together induced typical symptoms of SPVD when graft-inoculated to virus-free sweet potato. SPCSV alone caused stunting and either purpling or yellowing of middle and lower leaves when graft-inoculated to virus-free plants of two cultivars. Similarly diseased naturally inoculated field plants were shown consistently to contain SPCSV. Both this disease and SPVD spread rapidly in a sweet potato crop.

In attempts to use cross-reacting antibodies for the broad-spectrum detection of potyviruses two broad-spectrum immunoreagents, the monoclonal antibody P-3-3H8 and antiserum Tu MV-314 raised against an isolate of peanut stripe virus and turnip mosaic virus, respectively, were examined for their ability to detect members of the Potyviridae in a simple indirect plate-trapped antigen (PTA) ELISA. Both immuno-reagents reacted strongly not only with isolate of 50 different virus species of the genus Potyvirus but also with several isolates of ryegrass mosaic virus, the type member of the genus Rymovirus A few members of the genus Potyvirus as well as agropyton mosaic and hordeum mosaic viruses, two other species of the genus, Rymovirus did not react with P-3-3H8 but only with TuMV-314 which showed the highest degree of cross-reactivity. In no case were positive reactions obtained with members of the genera Bymovirus and Ipomovirus. These two immunoreagents which appear to be directed to conserved epitopes gave good results when they were employed for detecting potyviruses in field samples from ornamental (Liliales) and leguminous plants. The potential and limitations of cross-reactive antibodies for the routine detection of potyviruses are discussed. Zusammenfassung Verwendung kreuzreagierender Antikorper zum Nachweis von Vertretern der Potyviridae In Versuchen zum Nachweis von Potyviren mit Hilfe von Antikorpem mit breiter heterologer Reaktivitat wurden zwei Immunreagenzien, der monoklonale Antikorper P-3-3H8 und das Antiserum TuMV-314, auf ihre Eignung zum generellen Nachweis von Mitgliedern der Familie Polyriridae eingesetzt, wobei ein einfaches indirektes ELISA-Verfahren, der “plate-trapped antigen” (PTA) ELiSA, zur Anwendung kam. Isolate von 50 verschiedenen Arten der Gattung Polyvirus wurden durch beide Immunreagenzien nachgewiesen. Daruber hinaus reagierten auch verschiedene Isolate des ryegrass mosaic virus, des Typvertreters der Gattung Rymovirus, mit P-3-3H8 and TuMV-314 im PTAELISA. Einige wenige Vertreter der Gattung Potyvirus sowie agropyron mosaic virus und hordeum mosaic virus, zwei weitere Vertreter der Gattung Rymovirus. reagierten nicht noit P-3-3H8, sondern nur mit TuM V-314, das die hochste heterologe Reaktivitat aufwies. Mit Vertretern der Gattungen Bymovirus und Ipomovirus wurden in keinem Falle positive Befunde erhalten. In weiteren Versuchen zum Routinenachweis von Potyviren in Feldproben von Zierpftanzen der Ordnung der Liliales sowie in Gemusepflanzens (Legutninosen) lieferten die beiden Immunreagenzien gute Ergebnisse. Die Vor- und Nachteile dieser kreuzreagierenden Antikorper zum Routinenachweis von Potyviren im indirekten ELISA werden diskutiert.

Potyvirus isolates were obtained in Taiwan from soybean showing crinkle, mottle, mosaic or blistering. They were identified as peanut stripe virus (PStV) on the basis of host range, serology, molecular weight of the capsid proteins and morphology of cytoplasmic cylindrical inclusions. PStV was found to be closely related serologically to adzuki bean mosaic virus (AzMV), blackeye cowpea mosaic virus (BICMV), and the bean common mosaic virus (BCMV) strain NY 15. A clear differentiation of PStV from these related viruses was possible on the basis of the cylindrical inclusion morphology. Only the peanut isolate of PStV from the USA and the three soybean isolates of PStV from Taiwan produced pinwheels, scrolls and curved laminated aggregates whereas the other serologically related viruses produced scrolls only. Whilst the peanut isolate of PStV infected all nine peanut cvs tested, the soybean isolate PN of PStV infected two peanut cvs only. AzMV, BICMV and two strains of soybean mosaic virus did not infect any of the peanut cultivars tested. On the other hand, nineteen and three of the 27 soybean cvs were susceptible to the soybean isolate PN and the peanut isolate of PStV, respectively. The capsid proteins of the peanut and the three soybean isolates of PStV and of AzMV appeared to be proteolytically undegraded and to have nearly identical molecular weights of 35 kD. Based upon results of virus surveys in soybean plantings in Taiwan, the incidence of soybean isolates of PStV in soybean is similar to that of soybean mosaic virus, suggesting that these PStV strains might be economically significant to soybean production m Taiwan.

Summary Mouse hybridoma cells, secreting monoclonal antibodies (MCA) against tomato spotted wilt virus, were produced and screened for virus specificity by an indirect triple antibody ELISA, using a rabbit polyclonal antiserum for antigen trapping. A Bulgarian virus isolate from tobacco was used for immunisation of mice and rabbits. One fusion eventually led to 10 stable hybridoma cell lines, all of which produced antibodies of IgG-type though of different subgroups. Since none of the MCAs reacted with TSWV structural proteins after electrophoresis and transfer to nitrocellulose, other methods were chosen to examine their protein specificity. Purified viral cores and detergent-solubilised envelope proteins were used as antigens for ELISA, or, alternatively, glycosylated viral envelope proteins were trapped onto microtitre plates coated with lectins in order to detect MCAs specific for them. Both methods, independently, led to the identification of two MCAs that were specific for envelope proteins of TSWV. Only these two antibodies reacted with intact TSWV particles when examined by immunogold labelling in the electron microscope. The reaction of all MCAs with 11 different TSWV isolates eventually led to the selection of one core- and one envelope-specific antibody for routine use. Core-specific MCAs revealed serological differences between isolates belonging to the common serotype (= lettuce serotype), but did not react with the serotype TSWV-I. When comparing different ELISA procedures, broadest reactivity and highest sensitivity with different isolates were obtained in an indirect test procedure, using goat anti-mouse antibody conjugates.

Two commercially available ELISA kits for water analysis, a microtiter plate-ELISA based on polyclonal antibodies (p-ELISA) and a magnetic particle tube-ELISA based on monoclonal antibodies (t-ELISA), were used to determine chlorpyrifos residues in soils. Comparison with a gas chromatographic method frequently applied was carried out by fortification experiments and by analyses of real soil samples. At concentration levels of 1.0, 0.1, 0.05 and 0.01 mg/kg, chlorpyrifos was reliably determined by the GC method. Application of the p-ELISA did not permit a reliable quantitation, while the t-ELISA was applicable in a concentration range of 0.05–1.0 mg chlorpyrifos/kg dry soil.

Available data suggests that lettuce big-vein disease is caused by the ophiovirus Mirafiori lettuce big-vein virus (MLBVV) but not by the varicosavirus Lettuce big-vein-associated virus (LBVaV), although the latter is frequently associated with the disease. Since the disease occurs worldwide, the putative coat protein (CP) open reading frames of geographically distinct isolates of MLBVV and LBVaV were sequenced. Comparison of both nucleotide and amino acid sequences showed a high level of sequence similarity among LBVaV isolates. Phylogenetic analysis of LBVaV CP nucleotide sequences showed that most of the Spanish isolates clustered in a phylogenetic group whereas English isolates were more similar to the USA isolate. An Australian isolate was closely related to the Dutch isolate. Genetic diversity among MLBVV CP nucleotide sequences was higher ranging from 0.2% to 12%. Phylogenetic analysis of MLBVV CP nucleotide sequences revealed two distinct subgroups. However, this grouping was not correlated with symptom development on lettuce or the geographic origin of the MLBVV isolates. Finally, a quick method based on RFLP analysis of RT-PCR amplicons was developed for assigning MLBVV isolates to the two subgroups.

Two isolates of the virus 246/94 and 277/94, acquired from thorn apple (Datura stramonium) and tomato (Lycopersicon lycopersicum (L.) Karst. Ex. Farw., syn. esculentum), respectively, were characterised biologically and serologically and compared with a local isolate of Potato virus Y (PVY) isolated from tomato and other potyviruses and isolates infecting vegetables. Both isolates of TMMV infected only 16 of 28 plant species inoculated mechanically and induced indistinguishable symptoms. The most susceptible hosts were D. metel, D. stramonium and Nicotiana glutinosa L. However, these isolates differed from the PVY isolate by infecting Datura spp. and Solanum demissum L., while the PVY isolate infected Chenopodium quinoa Wild and Capsicum annuum L. Isolate 277/94 was transmitted non-persistently by the aphid, Myzus persicae Sulz. from diseased tomato to virus-free D. stramonium, D. metel L., N. glutinosa and tomato plants and from these back to virus-free test plants of each species. Purified particles of isolate 277/94 contained a single protein species with a molecular weight of 39 kDa. Furthermore, in double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) antiserum to isolate 277/94 reacted strongly with a Yemeni isolate of TMMV (Y90/7), but did not react with any other potyvirus. This clearly shows that the Yemeni and Ethiopian isolates of TMMV are similar serologically. RESUME Datura stramonium et Nicandra physalodes Gaertn en Ethiopie. Deux formes du virus 246/94 et 277/94, ont ete obtenue respectivement partir du Datura stramonium et de tomates (Lycopersicon lycopersicum (L.) Karst. Ex. Farw., syn. esculentum) infectees. Leurs compositions biologique et serologique ont ete identifiees et comparees avec: d'autres potyvirus, un virus present dans les pommes de terre locales Y (PVY) et isole a partir des tomates, et d'autres formes de virus presents dans des legumes contamines. Les deux formes du virus TMMV ont contamine 16 des 28 plants inocules mecaniquement, provoquant des symptomes similaires. Les plants ou le virus s'est cependant le mieux developpe sont: le D. metel, le D. stramonium et le Nicotiana glutinosa L. Cependant, ces deux formes different du virus PVY dans la mesure ou ils ont contamine le Datura spp. et le Solanum demissum L, alors que le PVY a contamine le Chepodium quinoa Wild et le Capsicum annuum L. Le virus 277/94 a ete transmis de maniere non persistante par l' Aphid, Myzus persicae Sulz. Des tomates contaminees vers du D. stramonium, D. metel L., N. glutinosa et des plants de tomate saints, puis de ces plants infectes vers d'autres plans tests saints de chaque espece. Des particules purifiees du virus (277/94) contiennent une seule espece de proteine avec une molecule pesont 39 kDa. De plus, une enzyme sandwich d'anti-corps immunosorbent assay (DAS-ELISA) antiserum permettant d'isoler le 277/94, a reagi fortement avec la forme Yemenite du virus TMMV (Y90/7). Ceci demontre clairement que les formes Yemenite et ethiopienne du virus TMMV sont tres proches d'un point de vue serologique. (African Crop Science Journal 2001 9(3): 517-526)

Twenty-seven of 29 strains of viruses in the bean common mosaic virus (BCMV) subgroup of legume-infecting potyviruses reacted strongly with one or more of the monoclonal antibodies (MAbs) which are known to be specific for epitopes located along the 50 amino acids which constitute the N-terminal end of the viral coat protein. Approximately one half of the virus strains reacted with the N-terminal epitope specific (NTES) MAb 4G12 which is specific for epitope E/B4, while the other half reacted with NTES MAbs 4 Aff1 or 4F9 which are specific for epitope E/B3. All but two strains contained at least one of these epitopes while no strain contained both. Competitive assays using five sequential, non-overlapping, synthetic, 10mer peptides indicated that the amino acids critical for epitope E/B3 reaction were located at positions 5, 7, and 10 from the N-terminal end of the coat protein. By deduction we postulate that the amino acids critical for epitope E/B4 are located at positions 10, 16, and 17. Because epitope E/B3 requires isoleucine at position 10 for expression whereas epitope E/B4 requires valine to be expressed, no one strain can express both epitopes. Two viruses in our tests (azuki mosaic and Dendrobium mosaic viruses) had deletions in this portion of their sequence explaining their failure to react MAbs specific for either epitope. The critical amino acids for a third epitope, E/B3A, were located at positions 16 and 17. We found no correlation between any of the three N-terminal epitopes defined in this study and the presence or absence of any biological property that we could accurately measure: i.e., symptomatology, host range, or pathotype. However, when coat protein sequences were aligned according to epitope type E/B3 or E/B4, we found that sequences within groups had high levels of identity while between group identities were low. We also found that sequences in the 3′-end non-coding region exhibited similar relationships within and between epitope groups. Two strains of BCMV (NL-4 and RU-1) were found to possess coat protein sequences typical of epitope E/B4 but 3′-NCR sequences typical of epitope E/B3. These data suggest that both strains may be the result of natural recombinants between the two epitope groups.

In formal virus taxonomy, the names of orders, families, subfamilies, and genera are always printed in italics and the first letters of the names are capitalized. Informal taxonomic names are not italicized or capitalized. For example, the informal names ‘vesiculovirus’, ‘rhabdovirus’ and ‘mononegavirus’ refer to a member of the genus Vesiculovirus, the family Rhabdoviridae, and the order Mononegavirales, respectively. This vernacular use of taxon levels poses no difficulty when referring to virus families whose names are clearly distinct from genus names. In 40 of the 71 virus families, however, the family name is derived from one of the genus names of this family (e.g., Coronaviridae from Coronavirus). This problem is particularly obvious for the 12 families of plant-infecting viruses, ten of which derive their names from a genus name. Furthermore, the genus name Parvovirus has served as basis for coining both the family (Parvoviridae) and subfamily names (Parvovirinae). In all these cases, the use of informal names such as parvovirus lacks precision as it remains unclear if what is referred to is a member of the family Parvoviridae or only a species of the subfamily Parvovirinae or the genus Parvovirus. If one has to make precise distinctions between the taxonomic categories in a description of a virus family or order, some authors ignore the aforementioned problem while others opt for the formal usage of the various taxonomic categories. Whereas this is not a problem when one refers only occasionally to a taxon level, the frequent use of formal virus taxonomy often appears somewhat awkward and clumsy. Therefore, there is a need for informal vernacular usage of taxonomic terms which not only can be used both as nouns and in adjectival forms but also precisely denote the various taxon levels. For all those families whose names have been derived from a genus name, the above mentioned problem could be solved by renaming all genera whose names served as the basis for coining the names of higher taxa, i.e., by analogy to the genus Orthobunyavirus in the family Bunyaviridae, the genus Potyvirus would be renamed ‘Orthopotyvirus’. Since this would violate the stability principle in taxonomy and is likely to meet considerable opposition, the aforementioned problem could be solved by coining suffixes for vernacular names that are derived from the suffixes used in formal virus taxonomy and, by definition, denote the various taxonomic categories. Therefore, the following taxon-specific suffixes are proposed for vernacular use

Cultivated Allium, such as onion, shallot and garlic are infected by various viruses, most predominantly by potyviruses, carlaviruses and mite-borne filamentous viruses. Only potyviruses generally cause conspicuous symptoms in Allium spp. particularly when present in mixed infection with viruses of other taxa, e.g. carlaviruses. Virus diagnosis is especially complicated when taxonomically related viruses occur in mixed infections or, when virus concentration in singly infected Allium spp. remains extremely low.

During a survey of chickpea (Cicer arietinum L.) crops in western Iran in July 2009, leaf samples from yellow and stunted plants were collected from fields in the provinces of Kermanshah (n = 30) and Lorestan (n = 16). Symptoms suggested infections by luteoviruses, such as viruses of the Beet western yellows virus (BWYV) subgroup (e.g., Turnip yellows virus [TuYV]) (4) and Chickpea chlorotic stunt virus (CpCSV), a virus first described from Ethiopia (1) and recently reported from other countries of West Asia and North Africa (2). All 46 samples were analyzed by triple-antibody sandwich (TAS)-ELISA (3) using the luteovirus-specific monoclonal antibody (MAb) B-2-5G4 (1), a mixture of three MAbs (1-1G5, -3H4, and -4B12) to an Ethiopian (Eth) isolate of CpCSV (1), and six individual MAbs (5-1F10, -2B8, -3D5, -5B8, -6F11, and 6-4E10) to a CpCSV isolate from Syria (Sy) (2) in combination with a mixture of polyclonal antibodies to CpCSV and BWYV for plate coating. CpCSV-Eth and -Sy were used as positive controls. Six of the sixteen Lorestan samples and two of the thirty Kermanshah samples reacted with MAb B-2-5-G4, indicating infections with a luteovirus. While none of the 46 samples reacted with the mixture of the CpCSV-Eth specific MAbs, two (Lorestan No. 25 and Kermanshah No. 31) of the eight MAb B-2-5-G4-positive samples reacted strongly with each of the six individual MAbs to CpCSV-Sy. Since this indicated the presence of a serotype II isolate of CpCSV in these two chickpea samples from Iran, we tried to confirm this by reverse transcriptase (RT)-PCR. TRI-Reagent (Sigma, St. Louis, MO) was used for total RNA extraction from samples Nos. 25 and 31. RT-PCR was carried out using the primers 5′-CAC GTG AGA TCA ATA GTC AAT GAA TAC GGT CG-3′ (sense) and 5′-TTT GTA ATT ACC AAY ATT CCA-3′ (antisense) derived from the CpCSV coat protein (CP) gene and 5′ end of ORF5, the readthrough domain (RTD), respectively. In RT-PCR experiments, no amplification was observed from healthy plant extracts, but chickpea samples Nos. 25 and 31 yielded amplicons of ~1,100 bp, which were used for cloning and sequencing. The sequences of the complete CP gene and 5′ end of ORF5 (RTD) from the two samples were determined and deposited in GenBank (GU930837 and GU930838). Sequence analysis revealed that the two Iranian isolates were most similar to each other, sharing CP nucleotide and amino acid (aa) sequence identities of 97.8 and 99.1%, respectively. They differed from each other only in 3 of the 200 aa positions of their CP sequences and were indistinguishable in the 128 N-terminal aa positions of their RTD sequences. When using DNAMAN for phylogenetic analysis, they clustered with serogroup-II isolates of CpCSV from Egypt, Morocco, and Syria (2), with which they were most closely related (approximately 98% in CP aa sequence). While the two Iranian CpCSV isolates differed by approximately 10% in CP aa sequences from serotype-I isolates of CpCSV, they differed strikingly (by ~27%) in RTD aa sequences from CpCSV-Eth, a serotype-I isolate and the only CpCSV isolate for which RTD sequences are available. To our knowledge, this is the first report of the occurrence of CpCSV in Iran. The virus can cause yellowing and stunting of chickpea similar to symptoms caused by other viruses reported from this crop. References: (1) A. D. Abraham et al. Phytopathology 96:437, 2006. (2) A. D. Abraham et al. Arch. Virol 154:791, 2009. (3) A. Franz et al. Ann. Appl. Biol. 128:255, 1996. (4) K. M. Makkouk et al. J. Plant Dis. Prot. 110:157, 2003.

The serological relationships among strains of bean common mosaic virus (BCMV) (genus Potyvirus, family Potyviridae) were investigated by testing 13 isolates of the 10 known BCMV pathotypes with two monoclonal antibodies and six antisera to BCMV strains. In addition, other properties of serologically distinct BCMV strains were compared. Two groups of BCMV strains were obtained by ELISA and Western blot serology: serotype A contained the BCMV strains NL3, NL5, and NL8 and serotype B contained the BCMV strains NL1, NL2, NL4, NL6, US4, NL7, NY15, and Fla. SDS polyacrylamide gel electrophoresis and Western blotting of freshly purified preparations, and of extracts from leaves infected with eleven BCMV strains showed that the apparent molecular mass of the capsid protein of the serotype A isolates NL3, NL5, and NL8 are lower (about M(r) 33,000) than those of the serotype B isolates (M(r) 34,500 to 35,000). The normal lengths of the particles of the serotype A isolates were shorter (810-818 nm) than those of most isolates (except NL6 and NY15) of serotype B (847-886 nm). All isolates studied induced cytoplasmic pinwheel and scroll inclusions. Cells infected with serotype A isolates contained a specific type of proliferated endoplasmic reticulum which was never found in cells infected with serotype B isolates. The capsid protein gene of a representative member of each serotype was cloned and sequenced. Molecular mass calculations based upon nucleotide sequence-derived amino acid sequences yielded M(r) of 29,662 and 32,489 for the capsid proteins of the serotype A isolate NL8 and the serotype B isolate NL4, respectively. Comparison of the coat-protein sequences showed considerable differences at the N-termini whereas the core regions and the C-termini appeared to be highly conserved. Marked differences were also observed within the 3' non-coding regions of cloned cDNAs of NL 4 and NL 8. The striking differences between the two serotypes of BCMV strongly suggest that they be classified as two distinct potyviruses which naturally infect Phaseolus beans.

Lily mottle virus (LMoV), genus Potyvirus, an important virus of lily that also causes flower-breaking in tulip (1), is considered to have a natural host range restricted to the family Liliaceae. In 1996, escarole (Cichorium endivia L. var. latifolium LAM) plants growing in fields close to Torino, Italy, and showing mosaic and necrotic spots on outer leaves were infected by a potyvirus related to LMoV. The virus was identified by immunoelectron microscopy (IEM) done on experimentally infected Nicotiana benthamiana and Chenopodium quinoa. The virus isolated from escarole (LMoV-E) had an experimental host range similar to that of lily isolates of LMoV, although species within the Liliaceae were not tested. LMoV-E systemically infected all nine escarole cultivars and six of seven endive cultivars (C. endivia L. var. crispum LAM) but did not infect any of six lettuce and two chicory cultivars (C. intybus L. var. foliosum HEGI). Symptoms ranged from mild to severe mosaic and were generally more severe on escarole than on endive. Some of the same escarole, endive, and lettuce cultivars were inoculated with a typical LMoV isolate from lily (Le97/49, from A. F. L. M. Derks, the Netherlands), which induced mild systemic infections in only one escarole and one endive cultivar. Both cultivars were also susceptible to LMoV-E. LMoV-E was purified from N. benthamiana, and an antiserum was prepared. IEM decoration titer experiments were done with LMoV-E and four other LMoV isolates from Liliaceae and their homologous antisera. Heterologous titers ranging from identity to serological differentiation index values of 2 to 4 were obtained, confirming the identity of the escarole isolate as a LMoV strain and indicating considerable serological variability among LMoV isolates. In a field survey of endive and escarole crops in 1998, in the area where LMoV-E was first identified, the virus was again detected by enzyme-linked immunosorbent assay in 4 of 80 escarole plants tested. LMoV-E appears to be a LMoV strain particularly adapted to escarole. To our knowledge, this is the first report of LMoV identified in a naturally infected host outside monocotyledonous plants. Reference: (1) E. L. Dekker et al. J. Gen. Virol. 74:881, 1993.

Sweet potato virus disease (SPVD) is the most damaging disease of sweet potato Ipomoea batatas (L.) Lam. in Africa. It is caused by sweet potato feathery mottle potyvirus (SPFMV) plus either the West African strain of sweet potato chlorotic stunt crinivirus (Closteroviridae) (SPCSV-WA) (2) or the serologically distinct and apparently more severe East African strain (SPCSV-EA) (1). Typical symptoms of SPVD include severe plant stunting, leaf distortion, chlorosis, mosaic, or vein clearing (1). During a survey done in February 1998 of 48 farmers' fields in Lusaka Province and North Western Province of Zambia, sweet potato plants with typical SPVD symptoms were observed. Incidence was generally 1 to 5% but occasionally >20%. To determine which viruses (SPFMV, SPCSV-EA, SPCSV-WA) were present in symptomatic plants, enzyme-linked immunosorbent assays (ELISAs) were done on leaf sap extracts. Twenty-two SPVD-affected plants from Lusaka Province and 15 from North Western Province were tested and SPFMV and SPCSV-EA (but not SPCSV-WA) were detected in all samples. SPCSV-EA by itself may cause purpling or yellowing of lower or middle leaves (1). Eight plants showing these symptoms were collected from North Western Province, and SPCSV-EA only was detected in six of the samples. SPVD was also observed in a 1997 survey of crops near Antsirable, Madagascar; incidence was generally 20%; SPFMV and SPCSV-EA, but not SPCSV-WA, were detected in two SPVD samples tested. Our results are the first report of SPCSV in southern Africa. SPVD in the regions surveyed appears to be due to SPFMV and SPCSV-EA; SPCSV-WA was not detected. References: (1) R. W. Gibson et al. Plant Pathol. 47:95, 1998. (2) G. A. Schaefers and E. R. Terry. Phytopathology 66:642, 1976.

SUMMARY Seasonal periodicity in the incidence of cowpea golden mosaic (CGM) and lima bean golden mosaic (LBGM), two whitefly-spread virus-like diseases, corresponded closely with fluctuations in population density of their vector, Bemisia tabaci, at two contrasting sites in southern Nigeria. Peak catches of the vector followed the onset of rains after very high temperatures during the dry season; populations declined abruptly with continuous, heavy rainfall. At Onne, B. tabaci infested legumes at emergence and remained and reproduced on them but at Ibadan infestation was delayed and there was no evidence of reproduction on legumes. B. tabaci preferred LBGM-susceptible lima beans (Phaseolus lunatus) to resistant ones and more pupae of B. tabaci occurred on CGM-susceptible cowpea (Vigna unguiculata) cultivars than on resistant ones but these observations did not relate to the yellow-sensitivity of whiteflies. Resistance to CGM in cowpea, and to LBGM in lima bean, was identified amongst germplasm exposed to natural infection. Resistance was, in each case, associated with lower disease incidence, slower spread and milder expression of symptoms relative to susceptible cultivars. Vector non-preference for resistant cultivars may have contributed to reduced secondary spread.

Leaf samples of black bryony (Tamus communis L.) from Devon, UK, showing various virus-like symptoms contained potyvirus-like particles (normal length c. 790 nm) and cytoplasmic cylindrical (pinwheel) inclusions. In immunoelectron microscopy, particles of most samples reacted with antiserum to dioscorea greenbanding mosaic virus, a potyvirus isolate from Dioscorea rotundata in Togo which is related to yam mosaic virus from the Ivory Coast. Potyvirus particles were not transmitted by sap or aphids (Myzuspersicae) from infected black bryony to black bryony seedlings or Nicotiana benthamiana. One sample from a symptomless plant of black bryony contained a potexvirus which formed massed virion aggregates in the cytoplasm of cells of black bryony, Nicotiana benthamiana and N. megalosiphon. Virions of the potexvirus (normal length 553 nm) contained a coat protein with an apparent molecular weight of 27.7 kd. The potexvirus differed from an Italian potexvirus isolate from black bryony by a serological differentiation index of 4 and gave only weak or no reactions with 23 other antisera to potexviruses, including dioscorea latent virus. The potexvirus caused systemic symptoms in only a few host plants and could be transmitted back to black bryony in which it caused no symptoms. It is provisionally named tamus latent virus.

In comparative studies on potyviruses from West African yams (Dioscorea spp.) the following isolates were used: Dioscorea greenbanding mosaic virus (DGMV) and a Nigerian yam virus (YV-N), both isolated from Dioscorea rotundata, and a beet mosaic virus isolate from D. alata (BtMV-Y) formerly designated Dioscorea alata ring mottle virus. Naturally infected D. alata containing very few particles of BtMV-Y, contained primarily particles of a second potyvirus (Dioscorea alata virus, DaV) which could not be transmitted but which was included in these studies wherever possible. The normal lengths of DGMV, YV-N, DaV, and BtMV-Y were 754, 772, 805, and 812 nm, respectively. All viruses induced cytplasmic inclusions of the pinwheel type and laminated aggregates. In addition, the nucleoli of BtMV-Y infected cells contained characteristic electron dense inclusions. The buoyant density of purified DGMV and BtMV-Y in CsCl was 1.336 g/cm3 and 1.321 g/cm3, respectively. The sedimention velocities (Srel) of DGMV, YV-N, and BtMV-Y were 156, 158, and 162 Srespectively. In SDS-polyacrylamide gel electrophoresis the coat protein of purified DGMV and YV-N all migrated as a single band with an apparent molecular weight of 36 kd. Coat protein of purified DaV showed up to 5 bands with molecular weights of 36 to, 32 kd. Polypeptides of purified BtMV-Y had an estimated molecular weight of 35 kd but those from infected plant extracts had a molecular weight of 36 kd. DGMV, YV-N, and BtMV-Y particles contained a single nucleic acid with an apparent molecular weightof 3.2, 3.2, and 3.1 Md, respectively. Using λ-DNA digested with Hind III as a marker, the molecular weight of DGMV and BtMV-Y nucleic acid was calculated to be 3.6 Md ± 10%. The nucleic acid was determined to be single-stranded RNA by enzymatic digestion and by staining with acridine orange. In serological studies using immunoelectron microscopy (IEM), electro-blot immunoassay (EBIA), and enzyme-linked immunosorbent assay (ELISA), DGMV and YV-N were closely related. Strong serological reactions were also obtained in IEM and EBIA when DGMV and YV-N were tested with antiserum to yam mosaic virus (YMV). Antisera against DGMV, YV-N, and YMV also reacted strongly with DaV antigen. Serological reactions between these viruses and BtMV-Y were usually not found or were weak. A very close serological relationship could be detected between BtMV-Y and beet mosaic virus isolated from beet (BtMV); both isolates were also very similar in host range, symptomatology, and cytopathology. Zusammenfassung Charakterisierung von Potyvirus-Isolaten aus westafrikanischen Yam-Arten (Dioscorea spp.) Fur vergleichende Untersuchungen von Potyviren aus westafrikanischen Yam-Arten wurden folgende Isolate verwendet: Dioscorea greenbanding mosaic virus (DGMV) und ein nigerianisches Yam-Vims (YV-N), die beide aus Dioscorea rotundata isoliert wurden, sowie ein Rubenmosaikvirus- Isolat aus D. alata (BtMV-Y), das bisher als Dioscorea alata ring mottle virus bezeichnet wurde. Naturlich infizierte D. alata enthielten sehr wenige BtMV-Y-Partikel, aber zusatzlich uberwiegend Partikel eines zweiten Potyvirus (Dioscorea alata virus, DaV), das nicht ubertragen werden konnte. Dieses Virus wurde so weit wie moglich in die Untersuchungen einbezogen. Die Normallangen von DGMV, YV-N, DaV und BtMV-Y betrugen 754, 772, 805 und 812 nm. Alle diese Viren induzierten cytoplasmatische Einschlusse vom „pinwheel”-Typ sowie „laminated aggregates”. Zusatzlich zeigten die Nucleoli BtMV-Y infizierter Zeller charakteristische elektronendichte Einschlusse. Die Schwebedichte des DGMV in CsCl konnte mit 1,336 g/cm3 und die des BtMV-Y mit 1,321 g/cm3 bestimmt werden. Die relative Sedimentationsgeschwindigkeit (Srel) betrug Fur DGMV 156 S, Fur YV-N 158 S und Fur BtMV-Y 162 S. Mit Hilfe der SDS-Gelelektrophorese konnten die Hullproteine von gereinigtem DGMV und YV-N als einzelne Banden mit einem Molekulargewicht von 36 kd ermittelt werden. Das Hullprotein von gereinigtem DaV zeigte bis zu 5 Banden mit einem Molekulargewicht von 36 bis 32 kd. Polypeptide von gereinigtem BtMV-Y hatten ein Molekulargewicht von 35 kd, wogegen solche aus infizierten Pflanzenextrakten ein Molekulargewicht von 36 kd aufwiesen. DGMV- und YV-N-Partikel enthielten eine einzelne Nukleinsaure mit einem Molekulargewicht von 3,2 Md, BtMV-Y eine mit einem Molekulargewicht von 3,1 Md. Bei Verwendung der Hind III gespaltenen λ-DNA als Marker, wurde das Molekulargewicht der Nukleinsaure von DGMV und BtMV-Y mit 3,6 Md ± 10% errechnet. Als Nukleinsauretyp konnte durch enzymatischen Abbau bzw. durch Farbung mit Acridinorange einzelstrangige RNA nachgewiesen werden. In serologischen Untersuchungen wurden unter Anwendung immunelektronenmikfoskopischer Methoden (IEM), „electro-blot immunoassay” (EBIA) und „enzyme-linked immunosorbent assay” (ELISA) eine enge Verwandtschaft zwischen DGMV und YV-N nachgewiesen. Beide Viren zeigten starke serologische Reaktionen mit Antiserum gegen Yammosaikvirus (YMV) in ISEM, Dekoration (IEM) und EBIA. Antiseren gegen DGMV, YV-N und YMV reagierten stark mit DaV-Antigen. Die genannten Viren reagierten nicht oder nur sehr schwach mit Antiserum gegen BtMV-Y. Eine sehr enge serologische Verwandtschaft wurde zwischen BtMV-Y und einem Rubenmosaikvirus-Isolat aus Zuckerrube (BtMV) festgestellt. Beide Viren waren sich auch in bezug auf den Wirtskreis, die Symptomatologie und die Gytopathologie ahnlich.

Two serologically apparently identical tombusviruses were isolated from glasshousegrown tomato plants showing mottle and malformation of the upper leaves and stunting of the shoot tips and, at a low rate, from a pelargonium plant, respectively. Both plant species were received from growers in southern Germany. In agar gel double diffusion tests and immuno-electrophoresis, the two virus isolates could not be distinguished from a tombusvirus (MPV) isolated from pepper in Morocco by Fischer and Lockhart (1977), although there were some minor differences in the reported host responses. In the tomato planting, strong symptoms were produced only temporarily. The majority of the 104 tomato plants of 15 different cultivars which had become infected by MPV following mechanical inoculation of the leaves showed only mild symptoms in contrast to a similar group of plants which developed severe stunting and foliar deformation when infected with the type strain of tomato bushy stunt virus. MPV was translocated only occasionally to the upper parts of tomato seedlings which had been grown in virus-containing soil, although root infections were more frequent. MPV is apparently not a major threat to tomato cultivation in Germany.

Very labile rod-shaped particles measuring 324 and 152 nm × 18 nm were isolated only from lettuce plants affected with lettuce big vein (LBV) but not from healthy ones. An antiserum to these particles was prepared which enabled us to diagnose LBV-affected plants, using immunosorbent electron microscopy (ISEM) and enzyme-linked immunosorbent assay (ELISA). Clearly positive reactions were obtained in ISEM and ELISA even when symptoms of LBV-affected plants raised in soil from various locations were indistinct. Higher ELISA values were obtained with extracts from leaves than with those from roots. In ISEM high numbers of particles were trapped from extracts of LBV-affected plants with antiserum to tobacco stunt virus. Zusammenfassung Elektronenmikroskopischer und serologischer Nachweis von virusahnlichen Partikeln, die mit der Breitadrigkeit des Salats assoziiert sind Bei Verwendung einer japanischen Methode wurden labile, stabchenformige Partikeln von 324 und 152 nm Lange und 18 nm Dicke nur aus Salatpflanzen, die von der Breitadrigkeit (LBV) befallen waren, aber nicht aus gesunden Pflanzen isoliert. Es wurde ein Antiserum gegen diese Panikeln hergestellt, mit dem LBV-befallene Pflanzen im ISEM und ELISA diagnostiziert werden konnten. Mit beiden Verfahren wurden befallene Pflanzen, die in Boden verschiedener Herkunft gewachsen waren, auch dann nachgewiesen, wenn Symptome nicht oder nur undeutlich erkennbar waren. Im ELISA wurden hohere Reaktionen mit Blatt- als mit Wurzelextrakten erhalten. Im ISEM reagierten LBV-assoziierte Partikeln auch mit einem Antiserum gegen tobacco stunt virus.

The effects of natural and artificial break of dormancy on the detection of potato viruses Y (PVY) and A (PVA) in tubers of field-grown potato cultivars with primary and secondary infections were studied by enzyme-linked immunosorbent assay (ELISA). Both viruses were at low concentration and unevenly distributed in dormant -tubers. Four to six weeks after treatment with Rindite, maximum concentrations of PVY and PVA were detected at both tuber ends with generally higher values at the rose end than at the heel end. Slower and smaller virus increase and a retarded and/or limited virus translocation were observed in treated tubers of resistant cultivars. Consequently, detectability of PVY and PVA was higher in tubers of susceptible cultivars than in those of the resistant ones. Detection of both viruses was very difficult and unreliable in tubers after natural break of dormancy. The very low concentration of PVY and PVA in dormant tubers and their drastic multiplication in Rindite- treated tubers appear to be characteristic of potyviruses and are unique among the major potato viruses.