ARS | Publication request: Hybrid origins of cultivated potatoes

Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 30, 2010
Publication Date: October 5, 2010
Citation: Rodriquez, F., Ghislain, M., Clausen, A., Jansky, S.H., Spooner, D.M. 2010. Hybrid origins of cultivated potatoes. Journal of Theoretical and Applied Genetics. 121:1187-1198.

Interpretive Summary: Wild and cultivated potatoes, technically grouped in the genus Solanum, section Petota, are very similar. Their formal classification into species is difficult, and there are many conflicting publications (taxonomies) that recognize different numbers of species. This study uses DNA to study the variation and origin of the four species of cultivated potatoes recognized in the latest taxonomy: Solanum ajanhuiri, S. curtilobum, S. juzepczukii and S. tuberosum. The data support prior ideas of the origins of the first three of these species through crossing (hybridization) between cultivated and wild species. The data are useful for breeders in order to understand the genes involved in these species of use to their potato breeding programs.

Technical Abstract: Wild and cultivated potatoes, Solanum section Petota, is taxonomically difficult, partly because of interspecific hybridization at both the diploid and polyploid levels. The taxonomy of cultivated potatoes is particularly controversial. With DNA sequence data of the GBSSI (waxy) gene we here infer relationships among the four species of cultivated potatoes accepted in the latest taxonomic treatment (S. ajanhuiri, S. curtilobum, S. juzepczukii and S. tuberosum, the latter divided into Cultivar Groups Andigenum and Chilotanum). The data support prior ideas of allopolyploid origins of S. ajanhuiri from S. tuberosum Andigenum Group (2x = S. stenotomum) × S. megistacrolobum; S. juzepczukii from S. tuberosum Andigenum Group (2x = S. stenotomum) × S. acaule; and S. curtilobum from S. tuberosum Andigenum Group (4x = S. tuberosum subsp. tuberosum) × S. juzepczukii. For the tetraploid cultivar Groups of S. tuberosum, hybrid origins are suggested entirely within much more closely related species, except for two of three examined accessions of the Chilotanum Group that appear to have hybridized with the wild Chilean species S. maglia. Hybrid origins of the crop/weed species S. sucrense are more difficult to support and S. vernei is not supported as a wild species progenitor of S. tuberosum Andigenum Group.