Collapse of species boundaries in the wild potato Solanum brevicaule complex (Solanaceae, S. sect. Petota): molecular data

The Solanum brevicaule complex is a group of morphologically very similar w ild and cultivated potato taxa (Solanum sect. Petota). This study uses sing le to low-copy nuclear RFLPs and RAPDs to investigate their species boundar ies and relationships. Cladistic analyses of both data sets are largely con cordant with each other and with a recently published phenetic analyses of the same accessions using morphology. All three data sets separate members of the complex into populations from Peru and immediately adjacent northwes tern Bolivia, including most cultivated species accessions, and populations from northwestern Bolivia to Argentina. The molecular results suggest that the complex is paraphyletic as currently circumscribed. Many species of th e S. brevicaule complex should be relegated to synonymy.