A transgene‐centred approach to the biosafety of transgenic plants: overview of selection and reporter genes

Recombinant DNA techniques have given plant breeding a new dimension. No longer hampered by crossing barriers, it is now possible to isolate genetic information from any organism and transfer it to virtually any plant of interest. Plants in which new pieces of DNA are introduced by procedures other than sexual crossing are generally referred to as genetically modified, or transgenic, plants. From the first possibilities to create such transgenic plants, however, discussions began. There is general concern with respect to the relative safety and admissibility of the transgenic plants involved. The novelty of the transgenic approach as well as the apparent concern ask for careful evaluation of the acquired characteristics of any transgenic plant (Dale et al. 1993). Research has been and is devoted to the consequences of the introduction of transgenic plants in the environment. Studies of pollen dispersal and gene transfer from transgenic crops to related species (Kerlan et al. 1992; Scheffler et al. 1993; Dale 1994; Eijlander & Stiekema 1994; Mikkelsen et al. 199; Timmons et al. 1996; Metz et al. 1997, this issue) can be considered `transgene independent', yielding information irrespective.