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ABSTRACT
MON 87460 is a maize (Zea mays L.) product that expresses cold shock protein B to impart drought tolerance. Here we describe our evaluation of MON 87460 for agronomic and phenotypic parameters, ecological interactions, reactions to abiotic stressors, ability to persist in uncultivated areas, root growth, and across-season water use compared with those of a conventional control hybrid with a similar genetic background. These data were used for the environmental risk assessment of MON 87460, a process required for commercialization of any new genetically modified crop. Any statistically significant differences were considered in the context of the genetic variation known to occur in maize and were assessed for their potential impact on plant pest (weed) potential and their potential environmental impact. The environmental risk assessment included several product-specific studies to assess the trait for unintended effects such as tolerance to stresses other than drought. The results of these studies revealed no effects of the genetic modification that would result in increased pest potential or adverse environmental impact of MON 87460 compared with a conventional control and no evidence for pleiotropic effects. The results of the plant characterization studies and the subsequent environmental risk assessment support the conclusion that the environmental risks associated with cultivation or import of MON 87460 are no different from the risks associated with conventional maize.
Abbreviations: CSPB, cold shock protein B; DAT, days after treatment; GM, genetically modified; NPTII, Neomycin phosphotransferase II.
Drought stress is a major cause of yield reduction in maize (Zea mays L.), and its effects have far-reaching global socio- economic implications. In both temperate and tropical regions suitable for commercial maize production globally, the average annual maize yield loss attributable to moderate water deficits is approximately 15% (Barker et al., 2005). During periods of severe drought, these losses can be much higher and can potentially result in complete crop failure. Climate change is expected to increase the frequency of adverse growing conditions. In a 2008 report, the U.S. Climate Change Science Program concluded that a combination of increased temperature variability, altered rainfall patterns, and the resulting increases in drought frequency will magnify yield variabilit y (CCSP, 2008; Hatfield et al., 2008). Consequently, improving drought tolerance in maize is a major goal of plant-breeding efforts....