ARS | Publication request: The Use and Limits of AFLP Data in the Taxonomy of Polyploid Wild Potato Species in Solanum Series Conicibaccata

Submitted to: Conservation Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 21, 2007
Publication Date: April 1, 2008
Citation: Jimenez, J., Brenes, A., Fajardo, D., Salas, A., Spooner, D.M. 2008. The Use and Limits of AFLP Data in the Taxonomy of Polyploid Wild Potato Species in Solanum Series Conicibaccata. Conservation Genetics. 9(2):381-387.

Interpretive Summary: There are about 190 species of wild potatoes widely distributed throughout the Americas from the southwestern United States south to Argentina, Chile, and Uruguay. Many of these species are very similar to each other and they may not all be worthy of recognition as valid species. This study uses characters of the DNA of four species from Central America to examine whether these species are good species. The molecular data are unable to distinguish some species long thought to be distinct. The data suggest either that these species are hybridizing among each other or that they truly are not good species. Because species names are used to make inferences on their use, as in potato breeding programs, this study helps us to make better inferences about the useful traits of this species.

Technical Abstract: Solanum sect. Petota (tuber-bearing wild and cultivated potatoes) are a group of approximately 190 wild species distributed throughout the Americas from the southwestern United States south to Argentina, Chile, and Uruguay. Solanum series Conicibaccata are a group of approximately 40 species within sect. Petota, distributed from central Mexico to central Bolivia, composed of diploids (2n = 2x = 24), tetraploids (2n = 4x = 48) and hexaploids (2n = 6x = 64); the polyploids are thought to be polysomic polyploids. This study initially was designed to address species boundaries of the four Mexican and Central American species of series Conicibaccata with AFLP data with the addition of first germplasm collections of one of these four species S. woodsonii, as a follow-up to prior morphological, chloroplast DNA, and RAPD studies; and additional species of series Conicibaccata from South America. AFLP data from 12 primer combinations (1722 polymorphic bands) are unable to distinguish polyploid species long thought to be distinct. The data suggest a complex reticulate history of the tetraploids or the need for a broad downward reevaluation of the number of species in series Conicibaccata, a trend seen in other series of sect. Petota. Separately, we report the first chromosome count of S. woodsonii, as 2n = 48.