First report of Cucumber mosaic virus infecting Ocimum gratissimum (L.) in Calabar, Cross River State, Nigeria.

Leaf samples of Ocimum gratissimum (L.) exhibiting vein banding, mosaic and chlorotic spots were collected randomly from the field. The symptomatic samples reacted positively to specific CMV antibody in antigen coated plate enzyme linked immunosorbent assay and to confirm the presence of CMV, RT-PCR was performed using CMV-specific primers that amplify a 519 bp region from the viral coat protein gene. The expected amplicon shared homology of 97.06% with a Nigerian isolate MH178110. Phylogenetic tree constructed revealed the isolate in close association with CMV strains belonging to subgroup II. This is the first molecular evidence of CMV in O. gratissimum in Nigeria and adds to the list of natural host for the virus. © Indian Virological Society 2021.