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During the development of a genetically modified (GM) crop product, extensive phenotypic and agronomic 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 potential of the GM crop. Ultimately, these study results and those of other studies are used in an ecological risk assessment of the GM crop. In the studies reported here, seed germination, vegetative and reproductive growth, and pollen morphology of Roundup Ready 2 Yield(®) soybean, MON 89788, were compared to those of A3244, a conventional control soybean variety with the same genetic background. Any statistically significant differences were considered in the context of the genetic variation known to occur in soybean and were evaluated as indicators of an effect of the genetic modification process and assessed for impact on plant pest (weed) characteristics and adverse ecological impact (ecological risk). The results of these studies revealed no effects attributable to the genetic modification process or to the GM trait in the plant that would result in increased pest potential or adverse ecological impact of MON 89788 compared with A3244. These results and the associated risk assessments obtained from diverse geographic and environmental conditions in the United States and Argentina can be used by regulators in other countries to inform various assessments of ecological risk.

One source of potential harm from the cultivation of transgenic crops is their dispersal, persistence and spread in non-agricultural land. Ecological damage may result from such spread if the abundance of valued species is reduced. The ability of a plant to spread in non-agricultural habitats is called its invasiveness potential. The risks posed by the invasiveness potential of transgenic crops are assessed by comparing in agronomic field trials the phenotypes of the crops with the phenotypes of genetically similar non-transgenic crops known to have low invasiveness potential. If the transgenic and non-transgenic crops are similar in traits believed to control invasiveness potential, it may be concluded that the transgenic crop has low invasiveness potential and poses negligible ecological risk via persistence and spread in non-agricultural habitats. If the phenotype of the transgenic crop is outside the range of the non-transgenic comparators for the traits controlling invasiveness potential, or if the comparative approach is regarded as inadequate for reasons of risk perception or risk communication, experiments that simulate the dispersal of the crop into non-agricultural habitats may be necessary. We describe such an experiment for several commercial insect-resistant transgenic maize events in conditions similar to those found in maize-growing regions of Mexico. As expected from comparative risk assessments, the transgenic maize was found to behave similarly to non-transgenic maize and to be non-invasive. The value of this experiment in assessing and communicating the negligible ecological risk posed by the low invasiveness potential of insect-resistant transgenic maize in Mexico is discussed.

Insect-protected soybean (Glycine max (L.) Merr.) was developed to protect against foliage feeding by certain Lepidopteran insects. The assessment of potential consequences of transgene introgression from soybean to wild soybean (Glycine soja Seib. et Zucc.) is required as one aspect of the environmental risk assessment (ERA) in Japan. A potential hazard of insect-protected soybean may be hypothesized as transfer of a trait by gene flow to wild soybean and subsequent reduction in foliage feeding by Lepidopteran insects that result in increased weediness of wild soybean in Japan. To assess this potential hazard two studies were conducted. A three-year survey of wild soybean populations in Japan was conducted to establish basic information on foliage damage caused by different herbivores. When assessed across all populations and years within each prefecture, the total foliage from different herbivores was ≤ 30%, with the lowest levels of defoliation (< 2%) caused by Lepidopteran insects. A separate experiment using five levels of simulated defoliation (0%, 10%, 25%, 50% and 100%) was conducted to assess the impact on pod and seed production and time to maturity of wild soybean. The results indicated that there was no decrease in wild soybean plants pod or seed number or time to maturity at defoliation rates up to 50%. The results from these experiments indicate that wild soybean is not limited by lepidopteran feeding and has an ability to compensate for defoliation levels observed in nature. Therefore, the potential hazard to wild soybean from the importation of insect-protected soybean for food and feed into Japan is negligible. [ABSTRACT FROM AUTHOR]