Several taxa changed genotype affiliations in different gene trees and all discordant taxa were affiliated with vaccine-related genotype II in some gene trees ( Figure 1C ). For example, isolate AY562985 (Cockatoo/14698/Indonesia/1990) was affiliated with genotype II in the NP gene tree but with genotype VII in all other gene trees. This isolate occupied a long branch in the genotype VII sequences in the P gene tree. Isolate AY562989 (Dove/2736/ Italy/2000) was affiliated with genotype II in the M gene tree but with genotype VI in all remaining trees except the P gene, in which it was an outlier to all other genotypes. Isolate AY225110 (HB92 isolate V4 vaccine/China) affiliated with genotype I in M and L gene trees but with genotype II in other gene trees. Isolate EU167540 (Layer/SRZ03/China/2003) affiliated with genotype VII in all gene trees but it occupied a long branch in genotype II in F gene tree. A Shimodaira-Hasegawa test (SH-test) provided statistical support of taxon incongruence (p,0.005) among the gene trees (data not shown). Phylogenetic incongruence among genes suggests that recombination might play a role in class II aPMV-1 diversity.