Attenuation of a Highly Pathogenic Porcine Deltacoronavirus Strain CZ2020 by a Serial Passage In Vitro

Figure 3

Phylogenetic analysis of PDCoV strains CZ2020 along with other 67 reference PDCoV strains. The trees were constructed using the distance-based neighbor-joining method of the software MEGA 7.0 with 1000 bootstrap replicates, and the GenBank numbers for the reference PDCoVs are shown in the figure. (a, b) The trees were constructed based on the complete genome sequences (a) and the complete spike genes (b). The strains determined in this study were marked with solid black triangles. Scale bars indicate nucleotide substitutions per site.

(a)

(b)