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)