| Species of Solanum sect. Lycopersicon and sect. Petota have become important models for research in genome structure and function. They belong to the Solanaceae family, which is particularly important economically because it contains many fruits and vegetables. Section Lycopersicon is exclusively diploid, and about 70% of the species of section Petota are diploid, with additional polyploids at the triploid to hexaploid level. A clear understanding of the evolutionary relationships within subgenus Potatoe will greatly enhance conventional breeding strategies and management of wild and cultivated genetic resources.;Section Petota contains about 190 species, distributed from the southwestern United States, south to Chile, Argentina, and Uruguay; sect. Lycopersicon contains 13 species and occurs in a subset of this distribution from southern Ecuador, Peru, and northern Chile. The phylogenetic relationships of these sections have been the subject of study by many researchers, but these relationships remain unresolved because of low taxon sampling and the use of a limited number of molecular markers. This study uses many more molecular markers and a better representation of species than prior studies. It does not attempt to provide a definitive study of the evolutionary relationships within the sections, but rather to identify appropriate markers for future studies that should incorporate a thorough species sampling. My approach consists of examining (1) diverse markers on all 12 linkage groups, (2) amplification of a single band (in diploids) of representative taxa, (3) markers with length between 600-1200 bp that amplify with single pass sequencing, and (4) marker with over 60% of intron content appropriate for this taxonomic level of closely related species.;I here test the monophyly of sections Petota, Lycopersicon and their outgroups in sect. Etuberosum, Juglandifolium, and Lycopersicoides, using a multi-locus molecular phylogenetic approach. I also investigate the genomic contributors of potato polyploids, the patterns of evolution within these species, and identify the minimal number of genes required to obtain the same phylogeny relative to a larger data set. |
