STUDYING AND MANAGING THE RISK OF CROSS-FERTILIZATION BETWEEN TRANSGENIC CROPS AND WILD RELATIVES

Drawing on field studies of pollen dispersal, we identify features of the hybridization process that need quantification. Our emphasis is on standardized measures, as opposed to the idiosyncratic and often anec dotal methods with which gene now or out-crossing data are currently r eported. In addition to proposing specific maximum likelihood approach es, we summarize some results to date from small-scale field trials th at bear on the risks anticipated for large-scale commercialization. We conclude that absolute containment of recombinant pollen or genes is unlikely if physical isolation is the only containment strategy. Becau se we conclude that the escape of transgenic pollen is inevitable, we argue that the focus of risk analysis should be shifted towards the 'i nvasiveness' of transgenic plants and 'mitigation' of their impact on natural, as well as agricultural systems.