Unintended effects of a Phytophtora-resistant cisgenic potato clone on the potato aphid Macrosiphum euphorbiae and its parasitoid Aphidius ervi

Genetically modified (GM) plants may show unintended differences compared to the original varieties, due to the modification process. Such differences might in some cases affect non-target organisms linked to the crop into an agro-ecosystem. In this paper, we aimed to study interactions of two blight-resistant GM potato clones with the aphid species Macrosiphum euphorbiae Thomas, a non-target arthropod frequently feeding on potato plants and one of the major pests of that crop. One of the potato events used in our experiments caused an increased fertility of the aphids in the first generation, and consequently, a positive effect on the growth of the aphid population was estimated. When a second generation of the aphid was reared on potato leaves of the same GM event, differences in aphid fertility were no longer observed. Behavioural studies conducted in a wind tunnel using the aphid parasitoid Aphidius ervi Haliday indicated that neither of the two tested GM varieties had a significant effect on the attractiveness of potato plants towards the parasitoid. In planta tests proved to be sensitive protocols to detect unintended effects on a non-target arthropod; experimental results, however, indicate that these effects are not expected to be biologically relevant in this tritrophic system, if these GM events become available for commercial use in the future.