Phylogenetic studies of selected isolates of Potato virus Y (PVY) infecting vegetable crops in KwaZulu-Natal, Republic of South Africa

Abstract

Phylogenetic relationships of Potato virus Y (PVY) isolates infecting vegetable crops in KwaZulu-Natal, Republic of South Africa, were investigated. A 1 067 bp amplicon covering part of the coat protein gene and the 3′ non-translated region (NTR) of three PVY^O isolates infecting tomato (Solanum lycopersicum L.), one PVY^O isolate infecting pepper (Capsicum annuum L.) and one PVY^N Wilga isolate infecting potato (Solanum tuberosum L.) were amplified, cloned and sequenced. The 5′ NTR, P1, HC-Pro and part of the P3 regions (2 559 bp) of a PVY^N isolate infecting potato were amplified, cloned and sequenced. Sequence data were compared with sequences of PVY isolates from different geographical locations and subjected to phylogenetic analyses. The PVY^N isolate clustered with the European sublineage N and has five unique amino acid residues. The PVY^N Wilga isolate branched with the American PVY^O isolate in the O lineage. All PVY^O isolates infecting tomato and pepper were grouped in a new sublineage within the O lineage.