Field Trial with Cisgenic Potatoes: Sustainable Disease Resistance Sought
Zurich-Reckenholz, 05.05.2026 — Agroscope is testing the use of new breeding technologies by cultivating a late blight-resistant potato cultivar in the field. Authorised by the Federal Office for the Environment (FOEN), the field study serves as a basis for researching potato varieties containing no foreign DNA. These so called ‘cisgenic’ varieties reduce the need for plant-protection products and can better withstand extreme weather conditions.
In the last ten years, around 1000 Swiss farms have given up growing potatoes. The main reasons for this are the more frequent occurrence of diseases and pest infestation, greater restrictions on plant-protection product use, and the increasingly common occurrence of extreme weather conditions such as heatwaves or prolonged wet conditions. These factors make it difficult to cultivate potatoes successfully and lead to yield losses.
Enter a new Agroscope research project launched as part of the National Research Programme (NRP) 84. Agroscope is field-testing the potato line P49 27, developed at the University of Wageningen, on the Protected Site in Zurich-Reckenholz. Thanks to modern breeding technologies, this cultivar is resistant to potato late blight – the world’s highest-profile potato disease.
Wild potato confers natural defence
The line used in the trial contains the Rpi-chc1 resistance gene originating in the wild potato Solanum chacoense and thus benefits from a natural defence against potato late blight fungus. Since only a same-species potato gene was used, the line is considered ‘cisgenic’. The field trial lays the foundation for further research into potato cultivars with greater disease resistance and higher drought- and heat-tolerance.
Testing the potential of new breeding methods
This trial is anchored in a series of field trials conducted by the international CRISPS project which primarily studies genome-edited potato cultivars in addition to cisgenic varieties. Together with research partners from The Netherlands and Sweden, Agroscope is working on two varieties of especial importance for Switzerland – ‘Innovator’ and ‘Erika’ – and on the old ‘Désirée’ variety as the research standard. Over the next few years, the aim is to repair available resistance genes or deliberately switch off susceptibility genes in these varieties and then to field-test the plants.
Conventional breeding methods are increasingly reaching their limits in this context. They take a long time, often more than 20 years, and are unable to keep pace with new pathogens or rapid environmental changes. New breeding methods such as the CRISPR-Cas gene scissors offer a promising approach, enabling the precise breeding of natural traits in just a few years, without the inclusion of foreign DNA.
Links
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