Schematic representation of the two major clonal complexes: RT-104-complex (BCC6 population) and RT-4-complex ( B. cenocepacia IIIB population). Each number represents a restriction type (RT). Data are presented as burst diagrams obtained using the eBURST algorithm v3: the primary founder or ancestral genotype (blue) is defined as the RT that differs from the largest number of other RTs within the complex at only one locus, i.e. the RT that has the greatest number of single-locus variants (SLVs); linked single-locus variants (SLVs) (purple) are the RTs differing from the ancestral genotype at one locus; linked double-locus variants (DLVs) (cyan) are the RTs differing from the ancestral genotype at two loci; the subgroup founder (yellow) is the RT that appears to have diversified to produce its own SLVs, i.e. a RT with at least two assigned descendent SLVs.