Using Gene Flow Information in an Environmental Risk Assessment - Case Study of an Insect Protected Soybean.

During the development of a genetically modified (GM) crop product, extensive phenotypic, agronomic, and ecological data are collected to characterize the plant in comparison to a conventional control with a similar genetic background. The data are evaluated for potential differences resulting from the genetic modification process or the GM trait, and the differences—if any—are subsequently considered in the context of contributing to the pest (weed) potential or adverse ecological impact (ecological risk) of the crop or any sexually compatible wild relatives that can receive the trait through outcrossing and introgression. Outcrossing, introgression and gene flow information is useful for understanding certain aspects of the exposure component of the risk assessment.  An insect protected soybean has been developed to protect soybean from certain lepidopteran pests for soybean regions in South America.  In South America there are no sexually compatible wild relatives of soybean and therefore no measurable risk associated with outcrossing to wild relatives.  In some countries where Glycine soja (a sexually compatible wild relative of soybean) does occur soybean is imported for food, feed and processing.  As part of the risk assessment for import, potential gene flow to G. soja and potential consequences of gene flow was assessed.  In these cases environmental exposure was extremely low since grain is handled in confined systems designed to minimize grain loss during transport.  If grain is spilled, it would need to germinate, grow in an area where G. soja is present, cross and backcross with the G. soja for introgression to occur.  Each of these were determined to be low frequency events and thus exposure was extremely low to negligible.  Potential hazards were also assessed based on the insect protection trait and the soybean characteristics and were determined to be negligible.  Therefore, since exposure and hazard were negligible, the potential risk of insect protected soybean was also considered negligible.