Cowpea Aphid-borne Mosaic Virus Research Articles

Studies on the Detection of Viruses Infecting Capsicum Species in the Northern Zone of Cross River State, Nigeria

The objective of this study was to determine the occurrence, detection, and geographical spread of viruses that infect pepper (Capsicum spp.) in six towns spanning two local government areas (Yala and Ogoja) in the northern zone of Cross River State. A total of 348 leaf samples from symptomatic and asymptomatic pepper plants were randomly collected from farmer's fields during a survey in 2023–2024. The samples were then preliminary tested using an antigen coated plate enzyme-linked immunosorbent assay (ACP-ELISA) with seven antibodies specific for ToLCV, Cowpea aphid borne mosaic virus (CABMV), Cucumber mosaic virus (CMV), Potato virus X (PVX), Tobacco mosaic virus (TMV), and Pepper veinal mottle virus (PVMV). The findings showed that the viruses that infect pepper in Yala had a high cumulative mean incidence, accounting for 56.9% (198 infected samples). Yache in Yala had the highest virus incidence at 90%, while Bansara in Ogoja had the lowest at 40%. At different rates, ToLCV, CMV, PVY, and PVMV were found in the samples; PVX, TMV, and CABMV were not found. The CMV virus was the most commonly discovered of them. Additionally, mixed infections between the viruses—between ToLCV and PVY in Yache and between CMV and PVMV in Bansara—were found. This is the first report on account of viruses found in pepper in the northern part of Cross River State. The findings show that the viruses that cause the infections are common and might potentially be a threat to the production of pepper in that region.

Effects of cowpea aphid-borne mosaic virus infection on the growth and yield parameters of Sesamum indicum plants

The potyvirus cowpea aphid-borne mosaic virus (CABMV) is the main viral agent present in crops of Sesamum indicum in several regions of Paraguay. However, information about the effects of CABMV infection in S. indicum plants is scarce and the critical period for virus infection in S. indicum plants is unknown. This study aimed to evaluate the damage caused by CABMV on the development and yield of S. indicum plants experimentally infected at three phenological stages. Mechanical inoculations of CABMV were performed on S. indicum plants at the early vegetative stage, at the beginning of flowering, and during capsule and seed formation. An enzyme-linked immunosorbent Assay (ELISA) test was used to confirm virus infection on the inoculated plants using specific CABMV antisera. Plants inoculated 30 days after emergence (DAE) had severe systemic symptoms, but they were mild in mid and late-infected plants (60 and 90 DAE). Plant aerial dry weight was significantly affected by CABMV infection, reducing up to 71.6% compared to the control. Mid and late-infected plants experienced a lower level of damage, with an average aerial dry weight reduction of 17 and 14.2%, respectively. Furthermore, plants with early, mid, and late CABMV infections showed an average capsule per plant reduction of 97, 33.3, and 13.3%, compared to healthy plants. Seeds per capsule produced by CABMV-infected plants decreased by 93.5%, 21%, and zero, respectively. Viral infections also affected the 1000-seed weight in early infected plants, with a reduction of up to 93.3%. To prevent economic losses, it is crucial to have effective strategies for managing CABMV, particularly during the early stages of the crop.

Recurrent selection in Passiflora: a new approach for the development of cowpea aphid-borne mosaic virus resistant cultivars with desired agronomic traits

Recurrent selection in Passiflora: a new approach for the development of cowpea aphid-borne mosaic virus resistant cultivars with desired agronomic traits

TaqMan real-time RT-PCR for detection of cowpea aphid-borne mosaic virus and epidemiological aspects of passion fruit woodiness disease

TaqMan real-time RT-PCR for detection of cowpea aphid-borne mosaic virus and epidemiological aspects of passion fruit woodiness disease

Unlocking Cowpea's Defense Responses: Conserved Transcriptional Signatures in the Battle against CABMV and CPSMV Viruses.

Cowpea aphid-borne mosaic virus (CABMV) and Cowpea severe mosaic virus (CPSMV) threaten cowpea commercial production. This study aimed to analyze Conserved Transcriptional Signatures (CTS) in cowpea's genotypes that are resistant to these viruses. CTS covered up- (UR) or down-regulated (DR) cowpea transcripts in response to CABMV and CPSMV mechanical inoculations. The conservation of cowpea's UR defense response was primarily observed with the one hpi treatments, with decreased CTS representatives as time elapsed. This suggests that cowpea utilizes generic mechanisms during its early interaction with the studied viruses, and subsequently employs more specialized strategies for each viral agent. The potential action of the CTS-UR emphasizes the importance of redox balance, ethylene and jasmonic acid pathways. Additionally, the CTS-UR provides evidence for the involvement of R genes, PR proteins, and PRRs receptors-extensively investigated in combating bacterial and fungal pathogens-in the defense against viral inoculation. AP2-ERF, WRKY, and MYB transcription factors, as well as PIP aquaporins and MAPK cascades, also emerged as significant molecular players. The presented work represents the first study investigating conserved mechanisms in the cowpea defense response to viral inoculations, highlighting relevant processes for initial defense responses.

First report of Passion fruit green spot virus in yellow Passion fruit (Passiflora edulis f. flavicarpa) in Casanare, Colombia.

Passiflora edulis, commonly known as passion fruit, is a vine species of passionflower native to South America. In Colombia, yellow passion fruit (P. edulis f. flavicarpa) is the most important species in terms of net production and local consumption. Recently two brevipalpus transmitted cileviruses, (i) passion fruit green spot virus (PfGSV) and (ii) hibiscus strain of citrus leprosis virus C2 (CiLV-C2H) were detected in passion fruit in Brazil and Hawaii, respectively (Ramos-González et al., 2020, Olmedo-Velarde et al., 2022). CiLV-C2H infects both citrus and hibiscus in Colombia (Roy et al., 2015, 2018) but there was no report of PfGSV elsewhere apart from Brazil and Paraguay (Costa-Rodrigues et al., 2022). Apart from emerging begomovirus diseases, five major viruses are known to infect passion fruit in Colombia: soybean mosaic virus (SMV), cowpea aphid-borne mosaic virus, passion fruit yellow mosaic virus, cucumber mosaic virus, and a tentative Gulupa bacilliform badnavirus A (Cardona et al., 2022). Current findings of CiLV-C2H in passion fruit and PfGSV in hibiscus motivated us to investigate the possibilities of cilevirus infection in passion fruit in Colombia. During surveys, along with healthy yellow passion fruit leaves, five symptomatic plant samples from Meta and three from Casanare were collected before sent to the Molecular Plant Pathology Laboratory at Beltsville, MD under APHIS permit. Passion fruit samples from Meta showed leaf mottling, rugose mosaic, and leaf distortion, whereas leaf variegation, chlorotic spots, yellowing, green spots in senescent leaves and green vein banding were observed in the Casanare samples (Supp. Fig. 1). Total RNA was extracted using RNeasy Plant Mini Kit (Qiagen, USA). To know the potential cilevirus infection in these samples, three PfGSV specific (Ramos-González et al. 2020) and a CiLV-C2 generic primer pairs (Olmedo-Velarde et al. 2021) were used in the RT-PCR assays. All five passion fruit samples from Meta failed to produce either CiLV-C2 or CiLV-C2H or PfGSV amplicon whereas all three Casanare samples successfully amplified 321, 244 and 299 nts of PfGSV-RNA1 and -RNA2 amplicons using C13F/C13R, C6F/C6R and C8F/C8R primers, respectively. Bi-directional amplicon sequencing followed by BlastN analysis revealed ≥99% nt identity with the PfGSV-RNA1 (MK804173) and -RNA2 (MK804174) genome sequences. An optimized ribo-depleted library preparation protocol was utilized to prepare two cDNA libraries using the RNA extracts of a PfGSV suspected positive (Casanare) and a negative (Meta) samples (Chellappan et al., 2022). HTS libraries of Casanare and Meta samples resulted in 22.7 to 29.5 million raw reads, respectively. After adapter trimming and filtering, clean reads were mapped to the Arabidopsis thaliana reference genome and unmapped reads were de novo assembled (Chellappan et al., 2022). BlastN analysis from the assembled contigs identified 1-3 contigs corresponding to PfGSV-RNA1 and -RNA2, respectively, from Casanare sample whereas 3 contigs of SMV were identified in Meta passion fruit sample. No other virus sequence was obtained from either of the libraries. Assembled contigs covered 99.33% of the RNA1 and 94.42% of the RNA2 genome, with read depths of 64,474 and 119,549, respectively. Meta sample contigs (OP564897) covered >99% of the SMV genome, which shared >99% nt identity with the Colombian SMV isolates (KY249378, MW655827). Both RNA-1 (OP564895) and -2 (OP564896) segments of the Casanare isolate shared 99% nt identity with PfGSV isolate (MK804173-74). Our discovery identified PfGSV in Colombia, for the first-time outside Brazil and Paraguay. The findings of PfGSV in yellow passion fruit increases the potential threat and possibility of PfGSV movement via Brevipalpus sp. from passion fruit to other hosts.

First confirmed report of cowpea aphid-borne mosaic virus infecting Sesamum indicum in Brazil

First confirmed report of cowpea aphid-borne mosaic virus infecting Sesamum indicum in Brazil

Partial efficacy of early and temporary roguing to manage woodiness disease in pilot crops of passion fruit

AbstractThe potyvirus cowpea aphid‐borne mosaic virus (CABMV) found in Brazil causes passion fruit woodiness, a difficult‐to‐control disease that limits the yield of the fruit crop. The present study assessed the effectiveness of systematic roguing of diseased plants as an alternative disease management strategy in three pilot passion fruit orchards. Passion fruit plants were grown on trellises and visually inspected for symptoms once or twice a week to identify and remove CABMV‐infected plants. Systematic roguing of infected plants was initiated immediately after the detection of the first symptomatic plants after transplantation of seedlings to the fields and continued until approximately 20% of the plants were rogued. This effectively delayed infection in the young plants, as 80% remained healthy from 181 to 285 days after transplanting. At this stage of development, plants are more tolerant to virus infection. However, once roguing was interrupted, 100% of the remaining plants became infected within 64 to 126 days. In fields without roguing, the incidence of infected plants ranged from 65% to 100% at 90 days after transplanting. Although this study confirms the difficulty in managing the disease, the results also substantiate the systematic removal of diseased plants to effectively delay CABMV spread, thereby improving subsequent plant development and yield. To delay the spread of the virus, growers in passion fruit‐producing regions are advised to inspect plants at least once a week after transplanting seedlings to the field and eradicating diseased plants during the first 5 months after transplantation.

Occurrence of bean-associated cytorhabdovirus and cowpea mild mottle virus infecting cultivated and wild Passiflora spp. in Brazil

Bean-associated cytorhabdovirus (BaCV) is a strain of Cytorhabdovirus caricae (genus Cytorhabdovirus, family Rhabdoviridae) identified in Brazil, in bean and soybean plants, in mixed infection with cowpea mild mottle virus (CPMMV, genus Carlavirus, family Betaflexiviridae). Ensuing the report of citrus-associated rhabdovirus (CiaRV — a citrus strain of Cytorhabdovirus caricae) infecting passion fruit in China, we speculated that BaCV, and possibly CPMMV, could be present in passion fruit crops in Brazil. This was tested by screening cultivated and wild Passiflora spp., and hybrid by RT-PCR and amplicon sequencing, which confirmed the presence of BaCV and CPMMV in several Passiflora spp. A total of 114 surveyed plants were collected in multiple locations from 2016 to 2021 and BaCV was identified in 4 of 19 cultivated P. edulis plants from a commercial field in Distrito Federal, Central Brazil. Moreover, while BaCV was detected in 4 of the 55 Passiflora accessions sampled at the Germplasm Bank “Flor da Paixão” (BAG-FP), CPMMV was identified in 14 of these 55 Passiflora spp. and hybrid accessions. This is the first record of BaCV in P. edulis in Brazil, and CPMMV and BaCV in other wild Passiflora species in the world. To investigate the potential mixed infection of BaCV and CPMMV-infected plants and other viruses previously identified infecting Passiflora spp. in Brazil, RT-PCR was conducted with specific primers for lettuce chlorosis virus (LCV, genus Crinivirus, family Closteroviridae) and cowpea aphid-borne mosaic virus (CABMV, genus Potyvirus, family Potyviridae). Most of the inspected plants had a mixed infection with these viruses. Our results warrant further studies to evaluate these viruses’ epidemiology, impacts, and interactions in the passion fruit crop.

Characterization of Cucurbit Aphid-Borne Yellows Virus (CABYV) from Passion Fruit in Brazil: Evidence of a Complex of Species within CABYV Isolates.

High-throughput sequencing (HTS) has been an important tool for the discovery of plant viruses and their surveillance. In 2015, several virus-like symptoms were observed in passion fruit (PF) plants in Bahia state, Brazil. Using HTS technology, bioinformatics tools, RT-PCR, and Sanger sequencing, we identified the cucurbit aphid-borne yellows virus (CABYV, Polerovirus, Solemoviridae) in co-infection with cowpea aphid-borne mosaic virus (CABMV, Potyvirus, Potyviridae) in PF, in green manure, and spontaneous plants in several localities in Bahia. Complete genomes of CABYV-PF isolates were determined and analyzed with other CABYV isolates available in GenBank that have been identified in various countries. Phylogenetic analysis and pairwise identity comparison with CABYV isolates showed that CABYV-PFs are more closely related to French and Spanish isolates. Overall, analyses of all the CABYV genomes revealed that these could represent ten distinct species, and we thus proposed reclassifying these CABYV as isolates into ten species, tentatively named "Polerovirus curcubitaeprimum" to "Polerovirus curcubitaenonum", and "Polerovirus melo". CABYV-PF is a member of "Polerovirus curcubitaeprimum".

Genetic divergence for seed traits in Passiflora full-sib families under recurrent selection for resistance to the cowpea aphid-borne mosaic virus

Genetic divergence for seed traits in Passiflora full-sib families under recurrent selection for resistance to the cowpea aphid-borne mosaic virus

Updates on cowpea viruses in Southwest Nigeria: distribution, prevalence and coinfection.

The online version contains supplementary material available at 10.1007/s42360-022-00576-8.

Varieties’ Response of Vegetable Cowpea to Mechanical Inoculation of Cowpea Aphid-Borne Mosaic Virus in Burkina Faso


 Vegetable cowpea is eaten mainly fresh, in the form of young, immature pods, tender and sweet like the common bean. However, like cowpea with seeds, vegetable cowpea experience yield losses due to the cowpea aphid-borne mosaic virus (CABMV). This study aims to improve yields through the development of vegetable cowpea varieties resistant to CABMV. The study focused on ten varieties of vegetable cowpea, carried out in a greenhouse at the Kamboinsé research station using a randomized complete block design with three replications, all inoculated with CABMV. The data collection concerned resistance parameters. Mechanical inoculation made it possible to observe various symptoms of CABMV, thus highlighting the existence of variability within the varieties tested. Strong correlations were observed between several variables. Thus, the varieties of vegetable cowpea IT85F-2089-5, UG-CP-8, IT85F-2805-5 and Telma were identified as resistant, because belonging to the low severity classes and having a low value of area under the disease progress curve. On the other hand, the varieties RW-CP-5, UG-CP-6, IT83S-911, niébé baguette grimpant possessing a high severity class were judged to be susceptible. These resistant varieties will thus be able to contribute to the improvement of production and the protection of cowpea resources in Burkina.

Survey for Virus Diversity in Common Bean (Phaseolus vulgaris) Fields and the Detection of a Novel Strain of Cowpea polerovirus 1 in Zambia.

The production of common bean (Phaseolus vulgaris L.) is adversely affected by virus-like diseases globally, but little is known about the occurrence, distribution, and diversity of common bean-infecting viruses in Zambia. Consequently, field surveys were conducted during the 2018 season in 128 fields across six provinces of Zambia and 640 common bean leaf tissue samples were collected with (n = 585) or without (n = 55) symptoms. The prevalence of symptomatic fields was 100%, but incidence of symptomatic plants ranged from 32 to 67.5%. Metagenomic analyses of nine composite samples and a single plant sample of interest revealed the occurrence of isolates of Bean common mosaic necrosis virus, Bean common mosaic virus, Cowpea aphid-borne mosaic virus, Peanut mottle virus, Southern bean mosaic virus (SBMV), Cucumber mosaic virus, Phaseolus vulgaris alphaendornavirus 1 (PvEV-1), PvEV-2, Ethiopian tobacco bushy top virus (ETBTV), and a novel strain of Cowpea polerovirus 1 (CPPV1-Pv) of 5,902 nt in length. While CPPV1-Pv was consistently detected in mixed infection with ETBTV and its satellite RNA molecule, based on results of mechanical transmission assays it does not appear to be involved in disease etiology, suggesting that its role may be limited to being a helper virus for the umbravirus. Screening of the survey samples by real-time PCR for the viruses detected by high-throughput sequencing revealed the prevalence of single (65.2% or 417/640) over mixed (1.9% or 12/640) infections in the samples. SBMV was the most frequently detected virus, occurring in ∼29.4% (188/640) of the samples and at a prevalence rate of 58.6% (75/128) across fields. The results showed that diverse virus species are present in Zambian common bean fields and the information will be useful for the management of common bean viral diseases.

Viruses infecting purple passion fruit (Passiflora edulis f. edulis) in southwestern Antioquia, Colombia

Purple passion fruit is one of the most important crops in Colombia, but unfortunately, viral diseases have started to affect its productivity. Five viruses are known to infect this crop in Colombia: Soybean mosaic virus (SMV), Cowpea aphid-borne mosaic virus (CABMV), Passion fruit yellow mosaic virus (PFYMV), Cucumber mosaic virus (CMV), and the tentative species Gulupa bacilliform virus A (GBVA). In addition, emerging diseases caused by begomoviruses were reported on other Passiflora species in Colombia. The incidence of these viruses in adult plants, plantlets, and seeds from southwestern Antioquia was investigated based on molecular approaches. PFYMV and GBVA scored the highest incidence (>90%). Sequence analyses of the partial genomes confirmed the presence of PFYMV, SMV and GBVA variants in purple passion fruit plants grown in commercial fields at Antioquia.

Effects of Neem Aqueous Extract (Azadirachta indica) against Aphids and Aphid-borne Virus in Cowpea (Vigna unguiculata L. Walp)

Pests and diseases are among the major factors limiting plant growth and yields. Pests are known vectors of pathogens including viruses. Proper management of plant pests is an indirect means of controlling viral diseases in plants. This study aimed at comparing the potential of neem extract and a synthetic insecticide (lambda cyhalothrin) for the management of aphids and Cowpea aphid-borne mosaic virus (CABMV) in five different cowpea (Vigna unguiculata) genotypes and to determine the residual effects of the insecticide in the cowpea grains. The experimental field was laid out in randomized complete block design with three replicates. Treatments included; spraying of cowpea plots with aqueous neem extract and lambda cyhalothrin (LC) twice at foliage stage, once at flowering and podding stages. Control plots were left unsprayed. Data were obtained on growth and yields of cowpea genotypes as well as the pest and virus disease traits. Results of the Analysis of Variance (ANOVA) revealed that variations attributable to genotypes were significant (p ≤ 0.01) for cowpea yields and virus disease traits. Treatments applied influenced the occurrence of pests and virus diseases. Neem extract reduced aphid infestations and virus diseases as much as the insecticide. Ife BPC accumulated a very high level of LC (1.14 ppm) in its grain when compared with the maximum residue level (MRL) for lambda cyalothrin in cowpea seeds. The study concludes that the use of eco-friendly bio-pesticide such as neem aqueous extract is effective for the management of aphids and aphid-borne virus in cowpea fields.
 Keywords: Aphids; aqueous extract; cowpea; neem; pesticide; virus

Spatio-temporal distribution and influence of distance of diseased passion fruit plants in the dissemination of the Cowpea aphid-borne mosaic virus in semi-arid tropical region

The Cowpea aphid-borne mosaic virus (CABMV), of the genus Potyvirus (Potyviridae), causes the most prominent passion fruit (Passiflora spp.) disease in Brazil. The virus is transmitted in a non-circulating manner by many species of aphids. Chemical control of the vector insect is inefficient, due to the non-circulating nature of the virus-vector aphid relationship, and commercial species of passion fruit are susceptible to the virus. As such, comprehending the disease’s spatio-temporal dissemination dynamic may assist in outlining cultural control strategies, as chemical and genetic control are not used in this situation. The experiments were carried out in commercial fields in the cities of Petrolina-PE and Juazeiro-BA, where the mapping of diseased and healthy plants was carried out over time. The data regarding the incidence of the disease was submitted for analysis with Gompertz, Logistic, Monomolecular and Exponential growth models, in order to determine the best model and the progress rate for the disease’s growth curve. The spatial patterns of the disease along the planting lines and over time were determined using the doublets test and through logistic regression, applied to determine the influence of distance between diseased and healthy plants closer to the disease’s dissemination pattern. The growth model which best adjusted to the CABMV epidemics in passion fruit plants was the Logistic model, and no difference was observed between the ‘r’ rates of disease progress. The diseased passion fruit plants exhibited, in both fields, an aggregate pattern along the planting line with similar incidence values (4.16% and 6.74%). The fast development of the disease and the tendency toward aggregation between diseased plants were also confirmed with the analysis of distance through logistic regression. Thus, the production of seedlings in environments that are protected from aphids, systematic inspections for eradication of diseased plants (roguing) and the elimination of host weeds around the orchard may be used as management practices do eliminate inoculum sources and reduce the CABMV’s rate of progress

Metabolomic and Histological Response of Passiflora cincinnata Infected with Cowpea aphid-borne mosaic virus (CABMV) Reveals Changes in Asymptomatic and Symptomatic Phases

Passion fruit woodiness disease, caused by the Cowpea aphid-borne mosaic virus (CABMV), is one of the leading phytosanitary challenges of passion fruit production. Passiflora cincinnata has been recognized for its potential in genetic improvement due to its highest resistance to CABMV and other phytopathogens. Metabolomic and histological alterations of P. cincinnata infected with CABMV were evaluated and searched for differential responses during the asymptomatic or symptomatic infection phases to correlate them with the mechanisms of metabolic defense. The metabolites of infected plants were analyzed by liquid chromatography-mass spectrometry. Based on the metabolomic profile, the times of infection were grouped into early or late infection phases. The metabolites related to CABMV infection were classified as alkaloids, saponins, phospholipids and acids. This study can assist agricultural institutions or farms in the early diagnosis and correct management of CABMV infection and contribute to the genetic improvement of the Passiflora genus against this disease.

Avaliação da produção e qualidade de frutos de uma cultivar de maracujazeiro-amarelo infectada com o cowpea aphid-borne mosaic virus

Abstract This work aimed to characterize and evaluate the correlations between fruit and pulp characteristics of a commercial cultivar of yellow passion fruit (FB 200) infected with the cowpea aphid-borne mosaic virus (CABMV). The observation of natural infection occurred after the beginning of flowering. The parameters weight, length, and diameter, peel thickness, pulp yield, soluble solids content, titratable acidity, and the soluble solids content/titratable acidity ratio were evaluated. A completely randomized block design composed of 20 plots with five replications was adopted. The data were subject to descriptive analyses and Pearson’s Correlation at 1 and 5% of significance. CABMV has decreased the quality and physical characteristics of fruits, but they still could be destined for juice processing industries. Many parameters of the fruits presented significant positive correlations.

Effect of vegetable oil on the efficiency of transmission of cowpea aphid-borne mosaic virus by Aphis gossypii Glover in passion fruit plants

Effect of vegetable oil on the efficiency of transmission of cowpea aphid-borne mosaic virus by Aphis gossypii Glover in passion fruit plants