Genetically Modified Potato with Increased Resistance to P. infestans -Selecting Testing Species for Environmental Impact Assessment on Non-Target Organisms

Frøydis Gillund, Angelika Hilbeck, Odd-Gunnar Wikmark, Lise Nordgård and Thomas Bøhn

Infections of potatoes with Phytophthora infestans result in the most devastating potato disease worldwide, known as ‘potato late blight’. Its occurrence causes huge economic losses for potato producers. Current control measures – involving extensive use of fungicides – come with environmental costs.  Efforts have been made to develop commercial potato varieties with increased resistance to P. infestans, using a variety of approaches. Due to the remarkable ability of P. infestans to overcome resistance, conventional potato breeders have not succeeded in developing commercial potato varieties with resistance that is lasting. One approach, where genetic engineering is used to ‘stack’ (i.e. insert in tandem) genes with broad-spectrum resistance to P. infestans in commercial potato varieties, has recently been employed as a means to create genetically modified (GM) potato varieties which are expected to have more durable resistance. Several European companies and research institutes are involved in this research and field trials have taken place in several localities in Europe since 2006.

The mandate for the project reported here was to apply a procedure developed to select ecologically relevant testing species for assessing potential impacts on non-target organisms of GM-potato plants with increased resistance to P. infestans. This was done during an expert workshop involving 11 Scandinavian researchers with an expertise on terrestrial invertebrates, soil fungi and ecology in Scandinavian agro-ecosystems.  The workshop was a follow-up of a pilot workshop conducted in August 2011, where the initial steps of this selection procedure were applied (reported in the Biosafety Report 2011/05 (Gillund et al., 2011)). This report is an updated and extended version of that report. The report presents the findings from the workshop. The report also concludes that the Nordic populations of P. infestans have particularly high genetic diversity, which may strengthen the adaptive potential and virulence of the pathogen. As a consequence this control strategy may not effective in a Scandinavian context and it is  particularly important to develop a resistance management program prior to a potential commercialisation of this type of GM potato in Norway.

You can read the entire report here