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 PVYO isolates infecting tomato (Solanum lycopersicum L.), one PVYO isolate infecting pepper (Capsicum annuum L.) and one PVYN 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 PVYN 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 PVYN isolate clustered with the European sublineage N and has five unique amino acid residues. The PVYN Wilga isolate branched with the American PVYO isolate in the O lineage. All PVYO isolates infecting tomato and pepper were grouped in a new sublineage within the O lineage.