This project will test the hypothesis that sub-population structure in rice is predictive of transgressive variation and begin to characterize the underlying genetic basis of this phenomenon. To do this, we will:

1. Document the genome-wide differences in allelic variation within and between the different subpopulations of O. sativa and O. rufipogon using a highresolution SNP assay.
2. Undertake association mapping in rice using phenotypic evaluations for 26 core agronomic and grain quality traits.
3. Systematically develop genetic materials that will allow us to explore the relationship between diversity and transgressive variation that occurs when subpopulations are crossed.
4. Establish a dataset for rice that allows us to compare our results with those of the maize diversity project and augment the collection of genetic resources for the research community.

A better understanding of the genetic basis of transgressive variation in inbred crop species will have an immediate impact on the global research agenda for crop improvement. Presently, there is a great deal of interest in breeding hybrid rice as a mechanism for delivering superior varieties to farmers. The new genetic resources that will be constructed in this project will provide a systematic set of tools for exploring the genetic basis of transgressive variation in this inbreeding species.