Potato leafroll virus (PLRV) is a major pathogen of
potato with worldwide impact on seed and commercial production
of potato. In North America, the primary potato cultivars
grown by industry are not resistant to PLRV and require
the application of insecticides to control the aphid vector of
PLRV, so as to prevent PLRV infection of the crop. The
Solanum etuberosum- derived dominant gene Rlretb confers
resistance to PLRV and has been mapped to chromosome 4.
The previous closest marker to Rlretb, C2_At1g42990, was
mapped 13.6 cM from the gene in a BC3 population.
Cleaved amplified polymorphic sequence markers were developed
in the region surrounding C2_At1g42990 and
mapped along with Rlretb in 102 BC4 progeny. Sixteen
markers were identified surrounding Rlretb, with flanking
markers at 2.1 and 9.3 cM. Two markers, 1367-8a and
DMB32-11, both 2.1 cM from Rlretb, are shown to be well
suited for marker assisted selection. The development of additional
molecular markers more closely linked to Rlretb will
greatly facilitate its use in potato breeding and its continued
introgression into cultivated potato for the development of
PLRV-resistant cultivars