2.5 Phylogenetic analysis and sequence comparison
The σC genes of both newly identified NDRV isolates were subjected to the online BLAST program (https://blast.ncbi.nlm.nih.gov/Blast.cgi). And sequences sharing more than 95% nucleotide identity were downloaded for further genetic analysis with Clustal Omega. Furthermore, the phylogenetic tree was conducted by MEGA 6.0 software with the neighbor-joining method using 1,000 bootstrap replicates.