Fig. 3.

Phylogenetic analysis of putative recombinant breakpoint located at position 586 of Italy 02 and Genotype IV isolates. All twenty-six Spanish IBV field isolates were included in the comparison. Trees were generated by the Maximum Parsimony method with 1000 bootstraps in the Mega 3 package. 3a. Phylogenetic tree obtained when the S1 region from nt 1 to 586 in the alignment was used. Italy 02 and Genotype IV (in bold letters) isolates were clustered together in the same phylogenetic group. 3b. Phylogenetic tree obtained when the S1 region from nt 586 to 1623 in the alignment was used. Genotype IV isolates (in bold letters) were grouped with Spanish 4/91 cluster 1 isolates, whereas Spanish Italy 02 isolates formed an own phylogenetic cluster.