Figure 3

Maximum likelihood phylogenetic tree of HA sequences of HPAI H5N1 viruses and the subtree of clade 2.3.2.1. The virus isolated at Hekou Reservoir in Yulin of Shaanxi is indicated by a symbol (◆) and colored red. Viruses previously isolated at Sanmenxia Reservoir area were colored green. The virus isolated from a black-necked grebe in Inner Mongolia is colored purple.