Phylogeny of Solanum series Piurana and related species in Solanum section Petota based on five conserved ortholog sequences

Taxonomic complexity in wild potatoes (Solanum L. sect. Petota Dumort.) has led to widely conflicting treatments. Solanum ser. Piurana Hawkes is one of 21 series recognized in S. sect. Petota in the latest comprehensive taxonomic treatment by Hawkes in 1990. They are distributed from southern Colombia south through Ecuador to central Peru. The taxonomic limits of the series and validity of its constituent species were not resolved with previous studies. In the present study, a set of five conserved orthologous DNA markers (cos II) with 5342 bp of aligned length were used to infer the phylogeny of putative members of Solanum ser. Piurana and outgroups. The results agreed with a three-clade topology shown by previous studies within S. sect. Petota. Solomon ser. Piurana is expanded to include some species formerly included in S. sers. Conicibaccata, Cuneoalata, Ingaefolia, Olmosiana, Simplicissima, Tuberosa and Yungasensa. This expanded group is supported morphologically by the presence of moniliform tubers and coriaceous leaves in most species.