Inferred origin of several Native American potatoes from the Pacific Northwest and Southeast Alaska using SSR markers

Certain Native Americans from the Pacific Northwest and Alaska of the USA have grown potatoes in their gardens for many generations. In this study, the origin of several potatoes collected from Native gardens was investigated. Fourteen SSR markers covering the 12 potato homologs yielding a total of 199 alleles were amplified and scored in Solanum tuberosum Group Andigena (52 accessions), S. tuberosum Group. Tuberosum (39 accessions) and wild species (6 accessions). "Ozette" from the Makah Nation on the Olympic Peninsula in Washington State was closely related to "Maria's" and "Kasaan" potatoes collected from Native Alaskan gardens in Southeast Alaska. These three potatoes were more closely related to either two Mexican and one Peruvian andigena accessions or three Chilean Group Tuberosum accessions, while being relatively less related to the old European or modern varieties and most distantly related to Group Andigenum. "To-Le-Ak" was closely related to two Chilean tuberosum accessions and one old European variety. All Native potatoes harbored T-type chloroplast genome indicating that their maternal lineage is shared with Chilean Group Tuberosum. Using genetic relationship as a guide to origin it appears plausible that the Native American/Alaskan cultivars are either directly or indirectly from Mexico and Chile. These Native potato cultivars present a possible second route of diffusion distinct from the South America to Europe transfer which has been assumed to the sole means by which potato was spread out of South America.