Figure 1. Relationships among clonal lineages and distribution of recombination events in Verticillium dahliae.

The neighbor-joining tree was constructed in MEGA 5.10 [58] from 26,748 SNPs in 141 isolates of V. dahliae. Each clade or lineage had >99% bootstrap support out of the 1000 replicates. Clonal lineages (from top to bottom) 1A/1B, 2B³³⁴, 2A, 4B, 4A, 6 and 2B⁸²⁴ were named after their respective vegetative compatibility groups (VCGs) described previously. Lineage 2B^R1 was not previously described. Recombinant lineages 2B^R1 and 6 are indicated by arrows with an asterisk. Recombinant haplotypes are indicated by arrows, from isolates VEM481 (clade I), 395, V496 and V498 (clade II-1) and 320 (clade II-2). The number of unique recombination events associated with each hierarchy in the tree is shown on the right hand side (see also Table 3).