Use of a Self-Compatible Diploid Potato Genome Assembly and a Mutant Collection for Forward Genetic Studies

We have sequenced the genome of an inbred genotype of the self-compatible tuber-bearing wild Mexican diploid potato species Solanum verrucosum (VER54). The assembly is based on the latest sequencing and physical mapping technologies, such as Illumina short reads, PacBio long reads, BioNano Genomics optical maps and Dovetail artificial Hi-C data with scaffold N50 values within the multi-megabase range. The assembled genome was evaluated for completeness checking the presence of CEGMA core eukaryotic genes and validated locally by the alignment of the 96 BAC end sequences. Furthermore, Genotyping-by-Sequencing (GBS) of a F₂ backcross verrucosum population (VER54xVER3939) has been done to anchor the assembly into pseudomolecules.

The sequenced genotype is also being used as a model for forward genetic studies in potato. Mutant collections are being produced using ethyl methanesulfonate (EMS). The objective is to combine the two elements of the project (i.e de novo assembly and a mutant population) together to study mutants carrying interesting traits that can be physically located by mapping them on the genome. The generation of a genome sequence for S. verrucosum and a mutant collection are highly valuable genetic resources. The VER54 inbred genotype can serve as a genetic model for further studies about comparative genome structure and functionality of important traits within the Solanaceae family. One of these traits is the resistance to Phytophthora infestans which is encoded by several R genes that have been shown to be present in Mexican allopolyploid potatoes in which S.verrucosum is likely to be the A genome donor.