The taxonomy of wild and cultivated potatoes is in constant flux, with differing opinions amongst specialists on the delimitation of species and on the interpretation of now largely molecular data gathered to illuminate the relationships between species. Such specialists often contradict themselves over a period of a few years. Even molecular data does not always settle arguments on species boundaries and in some cases it appears that morphological concepts of species may be more reliable as recent speciation events may carry similar ranges of molecular variation into two or more daughter species. Apparent overlap in molecular diversity between these species can occur when assessed with only molecular data, and limited sampling provide confusing evidence.
In common with other potato genebanks we have, for the sake of stability and to provide clarity for our users, adopted a conservative approach to the incorporation of name changes and fusions or splits of taxa. The taxonomy used here is based on that of Hawkes (1990), with the following changes:
The last point has vexed potato researchers for many decades, but molecular research has revealed that the cultivated types of potato, with the exclusion of those arising directly from inter-species hybridisation, form a single genepool with different variants having arisen under domestication. Retaining species names for these variants is no longer tenable, and so we agree that all of these types should fall under the name Solanum tuberosum. Several infraspecific classifications have been proposed. The scheme of Dodds (1962) puts the diploid and tetraploid potatoes into four groups, Stenotomum, Phureja, Andigena and Tuberosum, with the last group broadly equivalent between Chilean potato and Western potato. Since then, Huaman and Spooner (2002) have erected a similar classification but with Chilotanum as the name given for Chilean potato and no comment on Western potato, and Spooner et al. (2007) fused all Andean diploid and tetraploid potatoes into one group Andigenum in conflict with the molecular data presented in their paper. We consider Stenotomum, Phureja, Andigena and Tuberosum as sufficiently distinct and well-recognised categories to continue their use to classify cultivated potato, and encourage the adoption of the scheme of Dodds (1962).
Dodds, K.S. (1962). Classification of cultivated potatoes. In “The Potato and its Wild Relatives” (D.S. Correll, Ed.), pp. 517-539. Texas Research Foundation, Renner, Texas.
Hawkes, J.G. (1990). The Potato: Evolution, Biodiversity and Genetic Resources. Belhaven Press, London.
