Genetic and phylogenetic analysis
The 91 complete S gene sequences of PEDV obtained in this study have been uploaded to GenBank with accession numbers from MZ160999 to MZ161089. Twenty-four reference sequences retrieved from the NCBI nucleotide database and the 91 identified sequences were used for a phylogenetic analysis. Multiple nucleotide sequence alignments were performed with Clustal W algorithm using MEGA 6.0 software. A phylogenetic tree based on S gene sequence was constructed by the neighbor-joining method using MEGA 6.0 software, with bootstrap values calculated for each node from 1,000 replicates (Hu et al., 2015; Kumar, Stecher, Li, Knyaz, & Tamura, 2018). The evolutionary tree was further visualized by iTOL v4 software (Letunic & Bork, 2019).