| Potato breeding is a time intensive process, lasting up to 15 years for the release of a marketable cultivar. Breeding starts with selection of germplasm that is equipped with the traits and characteristics the breeder is interested in releasing. Using tools and information at every selection step, breeders can identify superior genotypes for release.;A review of literature surrounding potato breeding, genomics, and molecular markers is presented, followed by three research projects pertaining to potato breeding for disease resistance. The release of three germplasm clones containing combined early blight and late blight resistance are discussed in chapter 2. These clones were identified from a cross of tetraploid material with know resistance to each disease, respectively.;First sequenced in 2011, the potato genome is still in its infancy. Recent release of the SolCAP SNP chip has contributed to our understanding of the potato's genomic structure, and has allowed breeders and scientists to begin to unravel the connection between genotype and phenotype. In this study, C287, a heterozygous diploid hybrid with resistance to Verticillium wilt, was sequenced using Illumina's hi-seq, paired ends platform. Using the resulting reads, and a genetic modeling tool, Pindel, we showed the absence of a previously unannotated putative resistance gene when compared to sequenced DM1-3 potato genome. Predicted genetic variation was confirmed using PCR primers designed to amplify designated regions shown to be absent in C287. This presence/absence variation may play a role in the resistance of potato species to Verticillium wilt. The use of molecular markers is complicated by wide genetic variation in wild potato species and other less adapted germplasm. In order to assess this variation, we evaluated the usefulness of two CAPS markers that have previously been shown to predict Verticillium wilt resistance. We found that specificity of these markers was further complicated by the existence of homologous gene clusters. Thus, continued efforts are needed to develop strategies to deal with structural and sequence variation within wild potato germplasm. |
