The genetic structure ofPotato virus Y(PVY) andTobacco etch virus(TEV) (Potyvirus) populations was investigated in pepper fields in two regions in Turkey. The diversity of PVY and TEV populations according to coat protein (CP) and VPg coding regions showed some similarity. All the isolates built a monophyletic group due to a single introduction event or multiple introductions of genetically similar isolates. All the isolates of both viruses showed evidence to the diversification for a long time. Based on VPg and CP sequences, all PVY isolates corresponded to clade C1. Turkish potyvirus isolates were only able to break thepvr21resistance allele and therefore belonged to pathotype (0, 1). ThePvr4dominant gene was found to be efficient and durable against PVY but not at all efficient against TEV. Consequently, thepvr22resistance allele, efficient resistance against PVY and TEV pathotype (0, 1) isolates, would be the most suitable strategy to control potyviruses. [ABSTRACT FROM AUTHOR]