Genomic regions differentiating hybridising oaks

Quercus robur and Q. petraea are two closely related species that actively hybridise. As such, the two species have been suggested by some as being merely ecotypes of the same species (Kleinschmit et al., 1995). Recent work, however, indicates that despite intensive gene flow, these species remain separate genetic entities and that characters distinguishing the two, retain an association in natural populations (Muir et al., 2000). Building on recent discoveries, this proposal aims to systematically screen for genomic regions that differentiate between the two species. Using a sampling strategy that allows for a test of species integrity, microsatellite loci will be screened in these populations to detect informative loci. Single nucleotide polymorphisms will be developed in the flanking regions of informative loci for a reliable species assignment of individuals. Informative markers will be incorporated into existing genetic maps. These results will identify genomic regions important to the identity and integrity of these oak species and should shed new light on the mechanisms involved in the maintenance of such taxa that have troubled taxonomists for decades. The results will also allow a test to be developed for the execution of an EC directive on the purity of seed material.