XVI International Botanical Congess

All molecular phylogenetic evidence suggests that maize was originally domesticated from the teosintes in Central Mexico. However, this does not preclude South American Indians from playing an important role in later stages of maize domestication. For this study, isozyme, mitochondrial, chloroplast, ribosomal, and knob phylogenetic data sets were analyzed in a biogeographical context. Importantly North and South American isozyme data sets were combined for this analysis. Principal components analysis was used to separate the various maize race dispersals throughout the Americas. These analyses support a model that one of the most important dispersals of maize came from South America. Another Mexico centered dispersal has also played an important role in the distribution of maize germplasm. Contrasts between nuclear with chloroplast data suggest that hybridization between maize races has played a critical role in maize domestication.