Comparative structural genomics of 1EBN potato: DArT markers for improved access to resistance genes

Bradeen, JM¹, M Iorizzo^1,2, H Mann¹, L Gao¹, EA Quirin¹, R Aversano², and D Carputo². ¹University of Minnesota, Department of Plant Pathology, St. Paul, MN 55108; ²University of Naples “Federico II”, Portici, Italy.

The potato tertiary genepool consists of 1EBN diploid species. Rich sources of resistance to biotic and abiotic stress, 1EBN species are sexually isolated from potato. Gene cloning and transformation of successful cultivars is an attractive possibility. But a lack of efficient marker resources and knowledge of genome structure impedes mapping and cloning in 1EBN potato. We developed high throughput, cost-effective, communal resources for mapping 1EBN species. Diversity Array Technology (DArT) is a microarray platform for marker analyses. Because they are detected via DNA hybridization, mapped DArT markers are comparable across populations, species, and laboratories. With DArT Pty. Ltd., we developed a potato DArT array of 16000 features; 9500 originate from 1EBN genomes. We are constructing DArT maps in S. bulbocastanum, S. commersonii, and S. pinnatisectum, disease and cold tolerant species from unique series within the tertiary genepool. Linkage maps of 750 to 1000 markers are anticipated. Mapped DArT markers will be sequenced, facilitating in silico comparison with tomato and potato genome sequences. Establishment of synteny amongst species will enable comparative genomics applications. Additionally, we are mapping more than 120 candidate disease resistance (R) genes in S. bulbocastanum using a BAC pooling strategy and DArT markers. These efforts will facilitate comparison of genome-wide organization of R genes within Solanum, will allow researchers to target genome regions harboring R genes in future mapping projects, and provide immediate, cloned candidates for resistance phenotypes mapping to these regions. (oral, Potato Genetics, PAA membership #311)