Fig. 1.

Phylogenetic analysis of the nucleotide sequences of hvVP2 of IBDV. The evolutionary history was inferred using the neighbor-joining method with 1000 bootstrap replicates. The optimal tree with the sum of branch length = 1.97063052 is shown. The tree is drawn to scale, with branch lengths in the same units as those of the evolutionary distances used to infer the phylogenetic tree. The evolutionary distances were computed using the maximum composite likelihood method and are in the units of the number of base substitutions per site. The analysis involved 105 nucleotide sequences. All positions containing gaps and missing data were eliminated. There were a total of 366 positions in the final dataset. Reference strains are identified by name and GenBank accession number. The phylogeographic genogroups are identified