Blackeye Cowpea Mosaic Virus Research Articles

BETTERSNAP: A NEW, EDIBLE PODDED SOUTHERNPEA

Bettersnap southernpea (Vigna unguiculata) was developed as a replacement for the popular cultivar Snapea. The new cultivar is well adapted for production throughout the southern United States where it can be expected to produce excellent yields of edible pods or snaps. Bettersnap is resistant to root knot, a severe root disease incited by several species of the root-knot nematode (Meloidogyne spp.), and blackeye cowpea mosaic virus, the major pathogen of southernpea in the United States. Observations of natural epiphytotics indicate that the cultivar is also resistant to scab (Cladosporium vignae) and cercospora leaf spot (Cercospora cruenta). The new cultivar has the same maturity and high yield potential as Snapea. Bettersnap is recommended for use as a home garden cultivar for spring, mid-season, and fall plantings. It is particularly recommended for trial as a commercial processing cultivar for the production of the immature green pods used for the ``snap” component of the popular mixed packs of fresh peas and green snaps.

Cowpea aphid borne mosaic virus-Morocco and South African Passiflora virus are strains of the same potyvirus.

High performance liquid chromatography (HPLC) profiles of tryptic peptides and partial amino acid sequence analysis have been employed to establish the taxonomic status of the Moroccan isolate of cowpea aphid-borne mosaic virus (CABMV). Some previous reports have suggested CABMV to be very closely related to blackeye cowpea mosaic virus (B1CMV) while other reports have concluded that this relationship is distant. In this report a tryptic digest of the coat protein of CABMV-Morocco was compared with those of the coat proteins of B1CMV-Type, B1CMV-W, the mild mottle strain of peanut stripe virus (PStV-MM) and the NY15 strain of bean common mosaic virus (BCMV-NY15), all of which are now recognised as strains of BCMV. The comparisons also included the NL-3 strain of bean necrosis mosaic virus (BNMV-NL3), which had previously been classified as a strain of BCMV. The HPLC peptide profiles indicated that CABMV-Morocco was distinct from BCMV and BNMV. Amino acid sequence analysis of peptides accounting for more than half of the coat protein confirmed that CABMV-Morocco was not a strain of BNMV or BCMV but was a distinct member of the BCMV subset of viruses that previously has been shown to include BCMV, BNMV, soybean mosaic virus, zucchini yellow mosaic virus, passionfruit woodiness virus and South African Passiflora virus (SAPV). Comparison of the partial sequence data with these and other published sequences revealed that the coat protein of CABMV-Morocco is very similar to that of SAPV suggesting that they are strains of the same virus. Since CABMV was described over 25 years earlier than SAPV, the name CABMV should take precedence and SAPV should be renamed CABMV-SAP, the South African Passiflora strain of CABMV.

Sequence data to settle the taxonomic position of bean common mosaic virus and blackeye cowpea mosaic virus isolates

The nucleotide sequences of the coat protein genes and 3' non-translated regions (3'-NTRs) of three isolates of bean common mosaic virus (NL1, NL3 and NY15) and one isolate of blackeye cowpea mosaic virus (W) were determined. Comparison of these sequences revealed that the coat proteins of NL1, NY15 and W were identical in size (287 amino acids) and exhibited an overall sequence similarity (94 to 97%), and 84 to 98% in their N-terminal regions. Furthermore, their 3'-NTRs were very similar in length [253 to 256 nucleotides (nt)] and sequence (93 to 96% similarity). In contrast, the coat protein of NL3 had only 261 amino acids and showed 87 to 89% similarity with NL1, NY15 and W whereas its N-terminal region revealed only 46 to 61% similarity. The 3'-NTR of NL3 also displayed appreciable differences, both in length (240 nt) and sequence (56 to 63% similarity). These results, in combination with earlier serological findings, justify the conclusion that NL1, NY15 and W should be considered strains of the same virus, i.e. bean common mosaic virus, and that NL3 is a strain of a different potyvirus for which the name 'bean black root virus' is proposed.

Evidence that cowpea aphid-borne mosaic and blackeye cowpea mosaic viruses are two different potyviruses.

The immunoreactivity of a panel of polyclonal antibodies and monoclonal antibodies (MAbs) raised against African isolates of potyviruses from cowpea and African yam bean was examined in ELISAs. A serological study including reference isolates followed by further characterization in differential hosts resulted in separation of the potyviruses into two distinct serogroups, one containing blackeye cowpea mosaic virus (BlCMV) and the other containing cowpea aphid-borne mosaic virus (CAMV). Using biotin-labelled MAbs, the BlCMV isolates were further subdivided into two serotypes and the CAMV isolates into five serotypes. Because both BlCMV and CAMV induce a very similar mosaic disease in cowpea, different ELISA procedures using mixed MAbs were evaluated and a single protocol was developed which allowed reliable diagnosis of both viruses.

Characterization of Peanut Stripe Virus Isolates from Soybean in Taiwan

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.

Serological and biological relationships among viruses in the bean common mosaic virus subgroup.

Bean common mosaic virus (BCMV), blackeye cowpea mosaic virus (B1CMV), cowpea aphid-borne mosaic virus (CABMV), azuki bean mosaic virus (AzMV), and peanut stripe virus (PStV) are five species of the genus Potyvirus, family Potyviridae which are seed-transmitted in beans or cowpeas. Eighteen isolates of BCMV, five isolates of B1CMV, four isolates of CABMV, and one isolate each of AzMV, and PStV were compared serologically using a panel of 13 monoclonal antibodies (MAbs) raised against BCMV, B1CMV, CABMV, or PStV in indirect enzyme-linked immunosorbent assay (ELISA). Four MAbs detected all virus isolates; one detected all isolates except those of CABMV. Three MAbs were specific only for serotype A isolates of BCMV. Four MAbs detected all serotype B isolates of BCMV plus all isolates of B1CMV, AzMV, and PStV. None of the antibodies distinguished among these four viruses. However, in biological tests with 11 bean cultivars selected for differentiating BCMV pathotypes, all isolates of B1CMV, AzMV, and PStV could be differentiated from the BCMV serotype B isolates by their reactions on a few bean cultivars in host group I and the cowpea cultivar California Blackeye #5. Potential problems that can arise from the use of nonauthenticated isolates are also discussed.

A proposal for a bean common mosaic subgroup of potyviruses.

In order to elucidate the taxonomic positions of bean common mosaic virus (BCMV) and blackeye cowpea mosaic virus (B1CMV), several strains of these viruses were compared on the basis of host ranges, antigenic properties established with antisera to virions and to N-terminal peptide domains of their coat proteins, and high performance liquid chromatographic peptide profiles. The comparison includes three strains of BCMV, viz. NL1, NL3 and NY15, four strains of B1CMV, viz. Fla, Ind, NR, and W, and the Moroccan isolate (Mor) of cowpea aphid-borne mosaic virus (CABMV), formerly designated as B1CMV-Mor. Based on these parameters, Fla, NR, and W are strains of one virus, whereas NL3, Ind and CABMV-Mor (and possibly NL1 and NY15) are separate viruses. In view of these characteristics which allow similar viruses to be separated, we propose that these viruses be included in a bean common mosaic subgroup of the genus Potyvirus.

Coat protein properties suggest that azuki bean mosaic virus, blackeye cowpea mosaic virus, peanut stripe virus, and three isolates from soybean are all strains of the same potyvirus.

The interrelationship of a number of potyviruses infecting legumes has been investigated by comparing molecular properties of their coat proteins. Comparison of the coat proteins by the techniques of amino acid analysis and PAGE was inadequate to distinguish strains from distinct potyviruses. However, high-performance liquid chromatographic peptide profiles of tryptic digests of coat proteins of these legume-infecting potyviruses enabled such assignments to be made. These data indicate that amino acid sequences of coat proteins of azuki bean mosaic virus, the Type and W strains of blackeye cowpea mosaic virus, three isolates (74, PM, PN) of a potyvirus obtained from soybean in Taiwan, and the Blotch and Mild Mottle strains of peanut stripe virus (PStV) may be very similar to the known sequence of PStV Stripe coat protein. In contrast, peptide profiles of coat proteins from soybean mosaic virus, clover yellow vein virus, bean yellow mosaic virus, potato virus Y, and tobacco etch virus were dissimilar to each other and to the profile of PStV Stripe, suggesting that their coat protein sequences were also quite different. Based on observations of the coat protein structure of many potyviruses, the results suggest that the potyvirus isolates with similar coat proteins are strains of the same potyvirus.

Isolates of Bean Common Mosaic Virus Comprising Two Distinct Potyviruses

Strains of bean common mosaic virus (BCMV) have been identified largely by their characteristic interactions with a selected number of differential bean cultivars. Recent studies have suggested that BCMV strains could be classified on serological and other grounds as strains of two distinct potyviruses. Using high-performance liquid chromatographic peptide profiles of coat protein digests together with limited peptide analysis, 22 isolates of BCMV, including representatives from seven recognized pathotypes, were compared with each other and with the type strains of blackeye cowpea mosaic virus (BICMV) and peanut stripe virus (PStV) (...)

CAROLINA CROWDER: A NEW, PEST AND DISEASE RESISTANT, ALL-PURPOSE SOUTHERNPEA

The Agricultural Research Service of the United States Department of Agriculture announced the release of Carolina Crowder southernpea on 12 October 1990. The new cultivar is well adapted for production throughout the southern U.S., where it can be expected to produce excellent yields of high quality, crowder-type peas. Carolina Crowder is resistant to the cowpea curculio, the major insect pest of the southernpea in southeastern production areas; blackeye cowpea mosaic virus, an important virus pathogen of southernpea in the United States; and root-knot, a severe root disease incited by several species of the root-knot nematode. Canned samples of fresh Carolina Crowder peas scored well in three years of quality evaluation tests. Pod color is a brilliant red at early green-shell maturity and a brilliant red heavily shaded with cranberry colored pigment at optimum green-shell maturity. The attractive pod color should make Carolina Crowder an excellent candidate for fresh market use. Carolina Crowder plants have a greater tendency to produce a second crop than plants of most southernpea cultivars.

Inheritance of Resistance to Blackeye Cowpea Mosaic Virus in White Acre-BVR' Cowpea

Reciprocal crosses were made between `White Acre-BVR', resistant to blackeye cowpea mosaic virus (BICMV), and the susceptible `California Blackeye No. 5' cowpea [Vigna unguiculata (L.) Walp.]. Seedlings from `California Blackeye No. 5', `White Acre-BVR', F1, F2, and backcrosses were mechanically inoculated with BICMV, and evaluated 4 weeks later for symptom expression in the greenhouse. Plants were assayed by enzyme-linked immunosorbent assay. The resistance observed in the F1 and progeny from the backcross to the resistant parent indicated that resistance to BICMV in `White Acre-BVR' was dominant. Furthermore, a 1 resistant: 1 susceptible segregation of progeny from the backcross to the susceptible parent and a 3 resistant: 1 susceptible segregation of the F2 progenies suggested that the resistance to BICMV in `White Acre-BVR' was conferred by a single dominant gene.

Host Range, Cytology, and Transmission of an Alyce-clover Isolate of Blackeye Cowpea Mosaic Virus

A blackeye cowpea mosaic virus (BlCMV) isolated from alyce-clover, designated as BlCMV-AC, was partially characterized. Cylindrical inclusions containing scrolls induced by BlCMV-AC were detected in infected plants by light, electron, and immunofluorescence microscopy. Isolate BlCMV-AC infected Alysicarpus vaginalis, Crotalaria spectabilis, Indigofera hirsuta, Lupinus albus, Macroptilium lathyroides, Nicotiana benthamiana, Phaseolus vulgaris «Black Turtle 2», Vigna unguiculata subsp. unguiculata «California Blackeye», Chenopodium amaranticolor, and C. quinoa (.)

Purification, Serology, and In Vitro Translation of an Alyce-clover Isolate of Blackeye Cowpea Mosaic Virus

An isolate of blackeye cowpea mosaic virus (BlCMV) from alyce-clover (Alysicarpus vaginalis), designated as BlCMV-AC, and a Florida isolate of BlCMV (BlCMV-FL) were purified from systemically infected leaves of cowpea or white lupine. The A 260/280nm ratios obtained for purified preparations of BlCMV-AC and BlCMV-FL averaged 1.25 and 1.20, respectively. Analysis of purified BlCMV-AC by sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed a major and a minor protein component with relative molecular weights of 34,500 and 31,000, respectively (.)

Distinction of strains of bean common mosaic virus and blackeye cowpea mosaic virus using antibodies to N‐ and C‐ or N‐terminal peptide domains of coat proteins

SummaryEarlier attempts to discriminate serologically strains NL1, NL3 and NY15 of bean common mosaic virus (BCMV) and strain W of blackeye cowpea mosaic virus (B1CMV) had been unsuccessful. Antibodies directed towards N‐ and C‐, or N‐terminal peptide regions of the coat proteins of the above strains enabled the distinction between B1CMV‐W, BCMV‐NY15 and BCMV‐NL3 in electroblot immunoassay and in ELISA. The distinction was better with antibodies directed towards N‐termini than with those to N‐ and C‐termini. Strain NL1 of BCMV cross‐reacted with both B1CMV‐W and BCMV‐NY15, but not with BCMV‐NL3. Taxonomic implications of these findings are discussed.

Relationships among strains of bean common mosaic virus and blackeye cowpea mosaic virus ‐ members of the potyvirus group

SUMMARYIn host‐range studies, bean common mosaic virus strains (BCMV‐NL1, ‐NL3 and ‐NY 15) usually induced distinct systemic symptoms in susceptible bean cultivars and latent infection in several Vigna genotypes (except NY15 which gave mosaic symptoms in the latter), while blackeye cowpea mosaic virus (B1CMV‐W) caused distinct systemic symptoms in several Vigna genotypes and only weak systemic symptoms in a few bean genotypes only. Biologically, B1CMV‐W was closest to BCMV‐NY15 and less close to ‐NL1. When using antisera to the three BCMV strains and five strains of B1CMV (including a strain originally considered cowpea aphid‐borne mosaic virus CAMV‐Mor) in SDS‐immunodiffusion and ELISA, BCMV‐NL1 and ‐NY15 were found to be closely related to each other and to BICMV‐Fla, ‐NR and ‐W, and less closely to BICMV‐Ind and ‐Mor. Serological relationships of BCMV‐NL1 and ‐NY15 to BCMV‐ NL3 were more distant, which is in line with the biological distinction of NL3 in causing temperature‐independent necrosis in bean cultivars with the necrosis gene I. PAGE analysis of coat proteins revealed that the three strains of BCMV and B1 CMV‐W have similar but non‐identical molecular masses. Although molecular hybridisation may further elucidate quantitative relationships between potyvir‐uses, variation within and among the potyviruses may continue to pose problems in their classification and identification.

Inheritance of resistance to potato y viruses in Phaseolus vulgaris L

Resistance to watermelon mosaic virus-2 in Phaseolus vulgaris L. is conferred by two distinct dominant alleles at independent loci. Based on segregation data one locus is designated Wmv, the other, Hsw. The dominant allele Wmv from cv. Great Northern 1140 prevents systemic spread of the virus but viral replication occurs in inoculated tissue. In contrast, Hsw confers both local and systemic resistance to WMV-2 below 30C. At higher temperatures, plants that carry this allele in the absence of modifying or epistatic factors develop systemic veinal necrosis upon inoculation with the virus that results in rapid death. Patho-type specificity has not been demonstrated for either allele; both factors confer resistance to every isolate tested. A temperature-sensitive shift in epistasis is apparent between dominant alleles at these loci. Because Hsw is very tightly linked if not identical to the following genes for hypersensitivity to potyviruses I, (bean common mosaic virus), Bcm, (blackeye cowpea mosaic virus), Cam, (cowpea aphid-borne mosaic virus) and Hss (soybean mosaic virus), parental, reciprocal dihybrid F1 populations, and selected F3 families were inoculated with each of these viruses and held at 35 C. F1 populations developed vascular necrosis completely or primarily limited to inoculated tissue, while F3 families from WMV-2-susceptible segregates were uniformly susceptible to these viruses. The relationship between Hsw, Wmv and other genes for potyvirus resistance suggest patterns in the evolution of resistance and viral pathogenicity. Characterization of the resistance spectrum associated with each factor provides an additional criterion to distinguish genes for plant virus resistance.

Identification of blackeye cowpea mosaic virus from germplasm of yard-long bean and from soybean, and the relationships between blackeye cowpea mosaic virus and cowpea aphid-borne mosaic virus

Two potyvirus isolates, one from germplasm of yard-long bean (Vigna unguiculata ssp. sesquipedalis) irrtroduced into the Netherlands, and another one from soybean plants (Glycine max) in Indonesia, were compared with two virus isolates of blackeye cowpea mosaic virus (BICMV) from the USA and a Moroccan isolate of cowpea aphid-borne mosaic virus (CAMV). It is proposed that all five isolates be now considered B1CMV on the basis of host ranges, symptoms and serology. From our results, and a reassessment of the literature it is suggested to drop the name CAMV in favour of B1CMV. Additional keywords:" bean common mosaic virus, soybean mosaic virus.

Relationships among bean common mosaic virus, blackeye cowpea mosaic virus, azuki bean mosaic virus, and soybean mosaic virus.

The host range, transmission, cross-protection, antigenic relationships, and coat proteins of four distinct potyviruses (bean common mosaic virus (BCMV), blackeye cowpea mosaic virus (BlCMV), azuki bean mosaic virus (AzMV), and soybean mosaic virus (SMV)) were compared. BCMV, BlCMV, AzMV and SMV were easily distinguished by the host range and seed transmission. Two BCMV isolates, two BlCMV isolates and AzMV were serologically identical according to examination by agar gel diffusion plates containing 0.5% lithium 3, 5-diiodosalicylate. Five SMV isolates from Japan were serologically identical and distantly related to a SMV isolate from Thailand. BCMV, BlCMV and AzMV were distantly related to SMV. None of these viruses were serologically related to turnip mosaic virus (TuMV). Positive cross-protection was found between BCMV and BlCMV, between BCMV and AzMV, and between BlCMV and AzMV. The molecular weights of the coat proteins of the virus isolates estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, were 32.8×103(K) for two BCMV isolates, two BlCMV isolates and AzMV, 30.1K for five SMV isolates from Japan, 31.5K for a SMV isolate from Thailand, and 34K for TuMV. The patterns of the peptides of two BCMV isolates, two BlCMV isolates and AzMV after cleavage with Staphylococcus V8 protease appeared nearly identical. Likewise, polypeptide patterns of five SMV isolates from Japan were also very similar. Good correlation was found among serological typing, molecular weights, and peptide mapping data of 12 virus isolate proteins. These findings suggest that SMV is a distinct virus, while BCMV, BlCMV and AzMV are virus strains, not distinct viruses.

Is a helper factor necessary for infection of cowpea protoplasts with blackeye cowpea mosaic virus?

Bij inoculatie van mesofyl protoplasten van ‘cowpea’ met een zeer infectieuze, gezuiverde suspensie van ‘blackeye cowpea mosaic virus’ (BlCMV), een potyvirus, kon een infectie niet worden geconstateerd. Wanneer echter de bovenstaande vloeistof, verkregen na centrifugering bij laag toerental van sap van BlCMV-geinfecteerde planten, als inoculum werd gebruikt, dan kon vermeerdering van het virus in de protoplasten worden vastgesteld door middel van infectiositeitsproeven, immunofluorescentie en elektronenmicroscopie. Werd deze bovenstaande vloeistof, ontdaan van zijn infectiositeit, hetzij door bestraling met UV-licht, hetzij door centrifugering bij hoog toerental, en vervolgens gemengd met gezuiverd virus, dan trad er geen infectie van de protoplasten op.

Characterization of a Blackeye Cowpea Mosaic Virus Strain from South Carolina

Characterization of a Blackeye Cowpea Mosaic Virus Strain from South Carolina