Molecular and biological characterization of a novel botybirnavirus identified from a Pakistani isolate of Alternaria alternate.

•A new botybirnavirus (AaBbV1) isolated from a Pakistani isolate of A. alternata was characterized.•DsRNA1 encodes a polyprotein precursor for one of the two major structural proteins and RdRp.•DsRNA2 encodes a polyprotein precursor for the other major structural protein.•Two structural protein-coding regions on dsRNA1 and 2 are presumed to have duplicated during evolution.•Protoplast fusion assay showed asymptomatic infection of A. alternata by AaBbV1.