RAPD maps of the regions flanking the major gene for resistance to white pine blister rust in sugar pine. “R” designates the position of the resistance gene.  The RAPD primers used to produce marker bands are indicated at the right of each map. Blue numbers identify the four trees for which maps were constructed. Map distances  at the left of each tree are in centiMorgans. (Devey et al, 1995; Harkins et al, 1998)