Abstract:
One sweetpotato breeding line resistant to sweetpotato feathery mottle virus (SPFMV) was infected by graft-inoculation with SPFMV and developed severe symptoms of sweetpotato virus disease, following co-inoculation with sweetpotato chlorotic stunt virus. Coat protein (CP) gene sequences from eight East African isolates of SPFMV and two West Africa isolates from Nigeria and Niger were determined. Phylogenetic analysis of sequences of these isolates and those of non-East African origin previously reported, showed that the East African SPFMV isolates form a separate cluster. The monoclonal antibody MAb 7H8 divided Uganda SPFMV isolates into serogroups, which differed in prevalence in different districts of Uganda and in two common sweetpotato cultivars.