Submitted to: American Journal of Botany
Publication Type: Abstract Only
Publication Acceptance Date: 5/12/2000
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: The potato and its wild relatives, contains over 200 wild species distributed from the southwestern United States to south-central Chile. Most of these species grow in the Andes, but the United States, Mexico, and Central America contain about 30 taxa of diploids, tetraploids, and hexaploids. Chloroplast DNA restriction site data show 13 of these 30 taxa to form a clade containing only diploid species, but there is low resolution within this clade. We are analyzing members of this clade with phenetic analysis of morphological data, and two nuclear markers with the potential to show better resolution than chloroplast DNA restriction site data. Morphological data show extensive overlap of putative "species- specific" characters, but most species can be supported by multivariate techniques. We here also report on one nuclear marker, mapped microsatellites developed din Solanum tuberosum chosen because of their hypervariable nature. Preliminary data, using ten microsatellite markers distributed over seven chromosomes, strongly cluster some species but other morphologically different species cluster together, despite analyses of data as alleles or as each microsatellite variant as unrelated characters. There is considerable controversy regarding mutation processes of microsatellites and the best analytical method for phylogenetic studies. Our results suggest that microsatellites have reduced utility to analyze the United States, Mexican, and Central American diploid species.