Figure 2.
Phylogenetic trees for genomic segments of IDVs. (A–G) Nucleotide sequences of each segment are aligned and analysed in MEGA-X, with 1000 bootstrap replicates. Bootstrap scores of at least 50 are shown to the left of the nodes. Scale bar represents the number of substitutions per site. In the phylogenetic tree for the HEF segment (A), each branch of the five IDV major lineages (D/OK, D/660, D/CA2019, D/Yama2016, and D/Yama2019 lineages) is noted by red, yellow, green, light blue and dark blue colour, respectively, and the five lineage-representative IDVs are bolded. IDV strains identified previously in China are highlighted with colour background. IDV strains discovered in this study are marked with red stars. In phylogenetic trees for non-HEF segments (B-G), the five lineage-representative IDVs are bolded with red, yellow, green, light blue, and dark blue colour, respectively. IDV strains identified previously in China are highlighted with black background. IDV strains discovered in this study are marked with red stars.

