Genetically modified crops and hybridization with wild relatives: a UK perspective.
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 through spread of the crops themselves or through hybridization with wild relatives. Progress made in the genetic modification of the major UK crops is reviewed and those crops and traits in which genetic modification is most advanced are identified. Data on the potential for the spread of transgenes through pollen movement and the relative performance 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. Evidence for hybridization between crop and wild species in the UK is reviewed. Three categories of crop are identified on the basis of likelihood to form hybrids with wild relatives. The categorization of crops is used to suggest some simplifications to the procedures for permission to release genetically modified crops into the environment. Research priorities for ecologists are suggested on the basis of those traits that are of most interest to plant breeders using genetic modification, and the most likely route of escape of transgenes from a particular crop.