Cultivation of insect resistant maize MIR604

Advisory reports | 05.04.2011 | CGM/110404-01

This application concerns the cultivation of the genetically modified maize MIR604. MIR604 expresses the mCry3A gene conferring resistance to certain coleopteran insects and the pmi selectable marker allowing the plant to use mannose as a sole carbon source. Previously, COGEM advised positively on the import of MIR604 as well as import of several stacked maize lines containing MIR604.

During its long domestication process, maize has lost its ability to survive in the wild. In the Netherlands, the appearance of maize volunteers is rare and establishment of volunteers in the wild has never been reported. There are no reasons to assume that the introduced traits will increase the potential of maize to establish feral populations. The introduced genes cannot spread to closely related species since wild relatives of maize are not present in Europe.

COGEM is of the opinion that the molecular characterization of MIR604 is adequate.
The applicant conducted several laboratory and field studies to assess whether maize MIR604 affects non-target organisms (NTOs) adversely. Instead of using purified recombinant protein in laboratory experiments, the applicant used the entire E. coli suspension, containing a mixture of 40% expressed mCry3A protein and 60% of a larger mCry3A protein version. The laboratory experiments also exhibit other shortcomings: a predatory spider was not tested, the statistical power of the experiments and the obtained P value is not always given, the choice for the statistical test is not always explained and the applicant did not provide an explanation for the high mortality (over 15%) in certain control groups. In addition, in most NTO experiments, population growth, the method of choice for measuring both sublethal effects and mortality, was not studied. The applicant presents two studies on NTOs in the field, carried out with stacked maize line Bt11xMIR604xGA21. COGEM is of the opinion that a field test with the stacked line cannot replace a field test using the single event for risk analysis. Also, the field trials started quite late in the season, hampering the analysis of relevant life cycle stages of NTOs present in the field.

COGEM is of the opinion that the provided data are insufficient to allow a conclusion that cultivation of MON89034xNK603 exerts negligible effects on NTOs. Therefore, COGEM cannot advise positively on cultivation of maize line MIR604. COGEM points out that a food/feed safety assessment is carried out by other organizations. Therefore, COGEM abstains from advice on the potential risks of incidental consumption.

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