Occurrence and molecular characterization of Pepper veinal mottle virus from solanaceous crops

Abstract

ABSTRACT Potyviruses affect yield quantity and quality of solanaceous crops and a better understanding of their molecular properties is important for adequate disease management. Occurrence and molecular characterization of potyviruses associated with three solanaceous crops were studied. Thirty-four naturally infected leaves of pepper (Capsicum annuum L.), tomato (Solanum lycopersicum L.) and African eggplant (S. aethiopicum L.) were obtained and presence of potyviruses determined using degenerate primers targeted at the virus coat protein (CP) gene. Products were sequenced, and identities determined using the nucleotide option of the Basic Local Alignment Search Tool. Relationships between isolates were derived from phylogenetic trees using neighbor-joining algorithms. Positive amplifications were obtained only from pepper and tomato samples while sequence verification of amplicons identified only Pepper veinal mottle virus (PVMV) from eight isolates. Nucleotide and amino acid identities of PVMV CP gene ranged from 91% to 98% and 98% to 100%, respectively, confirming low genetic diversity within virus populations. Phylogenetic analyses clustered isolates into two sub-clades, indicating the presence of distinct PVMV strains. New CP-associated polymorphisms were identified in PVMV and the virus was established as the most prevalent naturally occurring potyvirus with low genetic diversity in the infected solanaceous crops. This information can be used toward the development of adequate management strategies for potyvirus infections in solanaceous crops.