Comparative structural genomics of disease resistant wild potato species comprising the tertiary genepool of cultivated potato

Liangliang Gao¹, Massimo Iorrizo^1,2, Harpartap Mann¹, Domenico Carputo², James M. Bradeen¹

¹University of Minnesota, Department of Plant Pathology, 495 Borlaug Hall, 1991 Upper Buford Circle, St. Paul, MN 55108 USA

²University of Naples “Federico II”, Department of Soil, Plant, Environmental, and Animal Production Sciences, Via Università 100, 80055 Portici (NA) Italy

The potato tertiary genepool consists of wild species that are sexually incompatible with cultivated potato. These species are rich sources of resistance genes to biotic and abiotic stresses, yet remain largely untapped. Here we report the development of genome-wide linkage maps for two potato tertiary genepool species, Solanum bulbocastanum and S. commersonii using Diversity Array Technology (DArT). These species represent phylogenetically distinct series within the potato tertiary genepool. We used mapping populations consisting of 92 F₁ progeny. The DArT array built for this study has 16,500 features, of which 9,500 are from tertiary genepool genomes. Preliminary data on polymorphism between the mapping parents suggest resulting linkage maps will be comprised of 750 and 1,000 markers for S. bulbocastanum and S. commersonii, respectively. Resulting maps can be further augmented with other marker sources and will be the first medium density genome-wide linkage maps for these species. The DArT platform will be tested for other tertiary genepool species, enabling cross-species comparisons. With ongoing genome sequencing projects in tomato and cultivated potato, sequencing of DArT markers mapped in wild potato will allow comparison of genome-wide structure throughout the genus Solanum.