Gene Flow from Wheat (Triticum Aestivum L.) to Aegilops L. Species

Hybridisation and introgression from crops to wild§relatives is a key issue in risk assessment. These§dynamics between wheat and tetraploid Aegilops L.§species were investigated by experiments in natural§conditions or in the greenhouse, and by genetic§analyses. DNA fragments from different wheat genome§areas were tracked along introgression lines with§Aegilops cylindrica Host, demonstrating that§transgene flow might occur significantly in a§scenario of wide cultivation of GM wheat. Insertion§of transgenes in unshared genomes between the species§would not necessarily prevent functional gene escape§into wild grasses. In order to describe crop-weed§dynamics in agroecosystems and to quantify§inheritance of transgenes, we assessed fertility of§the hybrid progeny, pollination distances, molecular§and chromosome constitution, and transgene§expression. The study then assesses population§genetic structure of wild Ae. cylindrica over two§continents, revealing a low genetic diversity within§the species. The last chapter describes early§generation introgression between wheat and Aegilops§geniculata Roth, the most widespread and frequent§Aegilops species in the Mediterranean area