Genetic Consequences of Clonal Versus Seed Sampling in Model Populations of Two Wild Potato Species Indigenous to the USA

Wild potatoes reproduce in the wild clonally by tubers or sexually by seeds. This case study examined the genetic consequences of sampling in situ clones or in situ seeds for model populations of two indigenous potato species of the USA, Solanum stoloniferum (formerly S. fendleri) PI 564039 and Solanum jamesii PI 605371. Solanum stoloniferum is a selfing disomic tetraploid while S. jamesii is a diploid that reproduces by outcrossing. Genetic diversity of in situ clonal collections and in situ seed collections of these species were compared with RAPDs. More diversity (i.e., RAPD polymorphism) was found within the tuber collection than seed collection for S. stoloniferum but for S. jamesii, the opposite was true, with seed collection capturing significantly more diversity than tubers. It has generally been assumed that collecting in situ seeds will result in capture of more genetic diversity. However, this work indicates that clonal collections may capture more genetic diversity, perhaps depending on the breeding behavior of the species.