Phylogenetic analysis of PKoV VP1 protein sequences detected in Sichuan province. The phelogenetic tree was constructed using the neighbor-joining method, Kimura 2-parameter model by MEGA version 5.0. Bootstrap values (based on 1,000 replicates) >75% are shown. Filled quadrate (■) indicates PKoV VP1 protein sequences obtained in this study. Filled triangle (▲) represents a Sichuan strain PKoV VP1 protein sequence has been reported in our previous study. Kobuvirus pig/JY-2010a/CHN isolate group contained 10 sequences from China forming a tight cluster. The Genbank accession numbers are: GU292548-GU292553, GU292556-GU292559; PKoV Thailand/Japan isolate group including 10 sequences clustered in a monophyletic branch. Their accession numbers in Genbak are as follows: AB624490, AB624492-AB624497, AB624499, AB624501, AB624503.