Understanding the origins of the diversity of species on earth remains a difficult question. In plants, it is apparent that much of this diversity is due to both doubling of the chromosomes of species (polyploidy) as well as hybridization among species. However, it remains unclear how these two processes interact in the evolution of new species. This project will test the hypothesis that polyploidy increases rates of hybridization among species relative to nonpolyploids using a group of closely related native plant species (Houstonia) as the study system. Chromosome numbers of natural populations of these species will be determined using cytological techniques. Molecular markers will then be used to assess the historical rate of hybridization among species with varying chromosome numbers.
The results of this research will enhance our understanding of polyploidy and hybridization, two of the most important modes of speciation in plants. Many of our most important crop species are either polyploids or hybrids, or both, including corn, cotton, and wheat, so understanding the interaction between hybridization and polyploidy could enhance agricultural breeding programs as well. This research will train both undergraduate and graduate students in biological research methods by giving them an opportunity to participate in data collection, management, and analysis, and conducting independent research.
