Figure 2

Unrooted maximum likelihood tree of Populus (Pt), Prunus (Pp) and Arabidopsis isopentenyl transferase ( IPT ) genes, which encode cytokinin biosynthetic enzymes. The tree is based on a deduced amino acid (282 aa) sequence alignment (Additional file 5: Figure S2). Support for each clade is given as ≥50% of bootstrap pseudoreplicates.