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.