Figure 3
An unweighted pair group method with arithmetic mean (UPGMA) dendrogram of all members of RFLP type 1-3-4 and those members of the spatial cluster detected in RFLP type 1-3-4. Solid grey rectangles indicate those viruses that are members RFLP type 1-3-4. Members of the spatial cluster are labeled with grey stars. A single vaccine-type virus was a member of the spatial cluster and is labeled at the bottom of the dendrogram with a solid grey circle and a grey star. The scale is in fraction of nucleotide dissimilarity over the ORF5 gene of PRRSV.