Gene flow between crops species and their wild relatives is a subject of growing interest since transgenic crops have been introduced in agriculture. The major concern is that the transgene might escape from genetically modified plants into wild populations of relatives, and could modify the fitness of the introgressed species and for instance increase its invasiveness. No genetically modified wheat is commercialized yet, allowing for risk assessment of introgression from wheat to wild before the release of transgenic wheat.

Here we assess gene flow between conventional hexaploid and tetraploid wheats, respectively Triticum aestivum (genome BBAADD) and Triticum turgidum (genome BBAA), and one of the most common tetraploid wild relative, Aegilops triuncialis (genome CCUU). For this purpose, we validated a set of chromosome specific EST-SSR markers from hexaploid wheat that display different alleles in reference wheat versus pure Aegilops triuncialis accessions. In populations from Aegilops triuncialis collected close or distant to wheat fields in the Mediterranean area and in North America, individuals showing evidence of introgression were genotyped to assess chromosome and genome-specific patterns of gene flow. These results will contribute to develop containment strategies.