Dissertation Research: Polyploid in Tragopogon: Multiple Origins and Mating System Diversification

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9624643 Soltis The appearance of new species in nature is an important event. New species may arise in the plant kingdom in a number of ways, one of which is through the combined processes of hybridization (cross-breeding) of two different species, and polyploidization (chromosome doubling). The result is a new, genetically distinct "polyploid" species that has twice the number of chromosomes as its progenitors. Research funded by this award addresses two main questions about this process: (1) Have the mating systems of the relatively young polyploid species diverged from mating systems of the parental species? (2) Has this combination of hybridization and polyploidization events occurred more than once in each species, and if so, how often? The research utilizes a model system for the study of plant evolution, the genus Tragopogon (Asteraceae). In Tragopogon, this type of species formation has occurred twice in the Palouse Region of the Pacific Northwest within the last 60 years. Understanding this process can provide new insights into how species can arise and what happens shortly after a species' origin. Because the same events of hybridization and polyploidization characterize the histories of some of our most important crops (e.g., wheat), information on this evolutionary pathway has implications for crop improvement through breeding and genetic engineering.