Twenty-Five Years of Collecting and Taxonomy of Wild Potatoes.

Wild and cultivated potatoes (Solanum section Petota) are a difficult group taxonomically, complicated by interspecific hybridization, introgression, allopolyploidy, a mixture of sexual and asexual reproduction, and possible recent species divergence. Various workers have interpreted the variation that results from these complications in different ways, and have provided quite different estimates of the number of species and their interrelationships. Investigations by various workers over the last 25 years have used a variety of integrated morphological, molecular, and biogeographical approaches to provide a more rational classification of the number of species, and have reduced their number from 232 in 1990 to about 100 today. In addition, there are redefined ingroup and outgroup relationships. These new classifications have been translated in very practical ways by modern taxonomic monographs. These new classifications putatively impact genebank management by simplifying and clarifying relationships in was that guide breeders to all others using the germplasm for basic scientific investigations; put another way, there is a degree of predictivity to taxonomy. Recent investigations question this assumption however, and by extension question predictivity in other fields like core collection strategies.