The wheat tribe, Triticeae, comprises about 350 grass species, including wheat, barley, and rye. Genetic exchange among species has played a major role in the group?s complicated evolutionary history, so a clear understanding of the relationships among species remains elusive. In species that exchange genetic material, the genomes can be mosaics derived from multiple sources, and as a result, evolutionary relationships inferred from genetic data can differ depending on which portion of the genome is used for the inference. Gene exchange has been convincingly implicated in the Triticeae, but the extent is still unknown. This research addresses the question by applying a genome-wide approach, sampling large numbers of short DNA sequences from throughout the entire genome from a broad sample of Triticeae species. The density of genome sampling, combined with the ability to determine the genomic location of the sampled sequences, will lead to a better assessment of the extent of genetic exchange, including which species are involved, and which regions of the genome are most affected.
The results of this work will be informative to Triticeae breeders who rely on the processes of hybridization and gene exchange as tools for crop improvement. The methods of data analysis developed in this project will be useful for studies of other groups of organisms that undergo gene exchange. The funding will support training for one graduate student, along with discussion groups and training for a selected group of undergraduates from Olive-Harvey College, a minority-serving two-year college in Chicago.
