Genetically modified wheat: No influence on insect larvae and aphids

Genetically modified wheat: No influence on insect larvae and aphids

Two projects of the Swiss National Research Program “Benefits and Risks of the deliberate release of Genetically Modified Plants” (NFP 59) have investigated the possible effects of fungus-resistant genetically modified wheat on fly larvae and aphids. The results have now been published in two scientific journals: The GM wheat had no influence on the development of the animals, or on mortality or reproduction.

Test field with different wheat varieties. The trials were carried out at two locations (Reckenholz/Zürich, Puilly).

Analysis. In the GM wheat lines various genes were tested for resistance against mildew, a fungal disease that is widespread in Switzerland and Middle Europe, which can lead to considerable problems.

Ruined. In June 2008 some of the trial plants were cut down by opponents of gene technology.

The researchers were interested in the effect of GM-wheat on fly larvae that decompose plant residues in the soil and so are involved in maintaining the soil fertility. Aphids were also chosen for study as they feed almost exclusively on plant sap and so are sensitive indicators for the food quality of the fodder plant.

Studies on fly larvae have been carried out by scientists at the Institute of Ecology and Evolution of the University of Bern. They fed larvae of two species of flies occurring in Switzerland with leaves from six different genetically modified wheat varieties. For comparison, larvae were also fed exclusively on six conventional strains of wheat. The researchers observed the development and the reproduction of the flies emerging from these larvae over four generations to see if there were any long-term effects. The different food sources had no effect on the fitness of any of the animals in any case.

A similar approach was chosen by the researchers at the Institute of Evolutionary Biology and Environmental Sciences at the University of Zurich in collaboration with the Research Station ART (Agroscope Reckenholz-Tänikon) for their project on aphids. In environmental chambers, 30 different aphid colonies were fed with eight different wheat species, four of which were genetically modified lines. The mortality, weight and fertility of the animals were recorded. All the measured parameters for all the differently fed aphids were comparable. No effects due to the genetic modifications were seen.

A moratorium for the commercial cultivation of genetically modified plants has been in force in Switzerland since 2005. In a referendum, the majority of the Swiss voted to ban the utilisation of genetically modified animals and plants initially to 2010. Until this time, research in the framework of the national research programme NFP 59 was meant to compile more knowledge on the use and risks of genetically modified plants. The moratorium was extended in February 2010 for another 3 years, to wait for the final results of the national research programme, which are expected to be available in mid-2012.

The Scientific Commission of the Swiss National Assembly was of the opinion that an extension would not lead to “any serious scientific disadvantage”. The research remains restricted, but “sowing under strict conditions” was still permitted for research purposes.

Documentation

Peter, M., Lindfeld, A. and Nentwig, W. (2010), Does GM wheat affect saprophagous Diptera species (Drosophilidae, Phoridae)?, Pedobiologia

(PDF avialiable by SNF; E-Mail: [email protected]) von Burg, S., Müller, C. B. and Romeis, J. (2010): Transgenic disease-resistant wheat does not affect the clonal performance of the aphid Metolophium dirhodum Walker. Basic and Applied Ecology, (PDF available by SNF; E-Mail: [email protected])