issue remains for all potato cultivars in the United States. One approach for increasing the resistance of cultivated potato to C^IS is to introgress CIS resistant germplasm from wild species relatives into S. ttéerosum. Several wild Solanum species show excellent resistance to CIS (Hamernik, 1998; McCann et al., 2010) and CIS resistant stocks have been developed from several Soliiimm species. For example, Solammi berthaultii Hawkes was used to produce the breeding clone S440, which has been used as a parental line by most potato breeding programs in the United States. Many new potato cultivars or breeding lines, including White Pearl (Groza et al, 2006), have been developed from S440. Progeny of S440 often have small tuber size and relatively low yields (Groza et al., 2006), however, and this tlecreascs their appeal to commercial growers. Thus, a more precise, targeted breeding approach based on molecular markers associated with CIS resistance is likely to be required for more effective introgression of CIS resistance from wild species germplasm (Bhaskar et al., 2010).