Analysis of gene flow in the lettuce crop-weed complex

Cultivated lettuce, Lactuca sativa, and wild prickly lettuce, L. serriola, have been shown to be closely related, if not conspecific. Even though both species are regarded as basically self-pollinating, outcrossing does occur, however to an unknown extent. In the context of an EU-funded project (acronym 'ANGEL'), an attempt is made to assess the level of gene flow between cultivated and wild forms by comparing the two, using the molecular marker systems of amplified fragment length polymorphism (AFLP) and the retrotransposon-based sequence-specific amplified polymorphism (SSAP). In addition, a marker system targeting disease resistance genes and gene analogues, called NBS (nucleotide-binding site)-directed profiling, is implemented in order to screen variation in genomic regions expected to be relevant for plant fitness and to play an important role in plant breeding