GENETICALLY-MODIFIED CROPS AND HYBRIDIZATION WITH WILD RELATIVES - A UK PERSPECTIVE

1. It has been suggested that genetic modification could lead to crops with enhanced invasiveness and persistence. These new genotypes could invade natural ecosystems and cause undesirable change, either throug h spread of the crops themselves or through hybridization with wild re latives. 2. We review the progress made in the genetic modification of the major UK crops, and identify those crops and traits in which gene tic modification is most advanced. 3. Data on the potential for the sp read of transgenes through pollen movement and the relative performanc e of modified and unmodified crops are examined. It is concluded that the spread of modified crops and their hybrids with wild relatives can be modelled in the same manner as for unmodified crops. 4. Evidence f or hybridization between crop and wild species in the UK is reviewed. We identify three categories of crop according to the likelihood of fo rmation of hybrids with wild relatives. 5. The categorization of crops is used to suggest some simplifications to the procedures for permiss ion to release genetically modified crops into the environment. 6. We suggest research priorities for ecologists based on the traits that ar e of most interest to plant breeders using genetic modification and th e most likely route of escape of transgenes from a particular crop.