Figure 2

Unrooted phylogenetic tree of Ty3/gypsy -like rt sequences (520 bp) isolated from Helianthus annuus (blue terminal branches) and Helianthus petiolaris (yellow terminal branches). Capital letters indicate major lineages (A = Surge1, B = Surge2, C = Surge3, D = Surge4, and E = Surge5). Bootstrap values (>50%) are shown for branches defining major lineages as well as for deeper internal branches and are based on 1,000 replications. Phylogenetic analysis was conducted using neighbor joining [75].