Figure 1From: Surveillance of avirulent Newcastle disease viruses at live bird markets in Eastern China during 2008–2012 reveals a new sub-genotype of class I virusPhylogenetic tree of class I NDV isolatess based on the older classification methods by the variable region (nt 47–420) of the F gene. The reference class I NDV isolates characterized in this study were shown in bold.Back to article page