Researchers breed new varieties of potato for organic farming

Aim of the project: Better disease resistance and greater tolerance to heat and drought

Organic farmers do not rely so heavily on fertilizer and use fewer chemicals to fight weeds, harmful insects and fungi. The crops they grow have to be able to thrive under these conditions. In a project involving Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), stakeholders from across Germany are aiming to breed new varieties of potato for organic farming. They should be less susceptible to disease and have a higher tolerance for heat and drought. In addition, the potatoes should utilize nutrients efficiently and be easy to process. The Federal Ministry of Agriculture and Food is providing approximately 2.8 million euros in funding for the project until the end of 2028.

One tiny pest probably had a decisive impact on the course of history: between 1845 and 1849, the pathogen that causes late blight destroyed virtually the whole potato harvest in Ireland, not just once, but several times. The great famine which ensued led to the deaths of approximately one million people. In the following decades, this led to Ireland increasing their efforts to gain independence from Great Britain after the British government exacerbated the crisis with its liberal economic policy. Countless people also emigrated to the United States of America as a result of the failed harvests. This included the ancestors of the later US Presidents John F. Kennedy and Joe Biden.

Even today, farmers still fear late blight. Even the modern varieties of potato are highly susceptible to the pest that triggers the disease, the microscopic oomecyte Phytophthora infestans. “The pathogen is capable of repeatedly overcoming resistance,” explains Privatdozentin Dr. Sophia Sonnewald from the Chair of Biochemistry at FAU. “While there are effective fungicides that kill the microorganism, their use is strictly regulated in organic farming.”

Patience is called for when cultivating stable breeding lines

The project KarOLa (whose name is taken from the German name for the project, an acronym standing for cultivating potatoes for organic farming that are tolerant against stress and suitable for processing) is taking a different approach. The involved institutions hope to breed new varieties of potato that are largely immune to late blight. One problem is that resistances obtained by cross-breeding are often not stable and are lost again if further down the line varieties are selected for characteristics such as a high yield,” says Sonnewald. “However, we would like to obtain varieties that are impervious towards disease and pests, process nutrients well, can be processed easily, are tolerant of drought and also have a high yield. That takes a lot of patience.”

Sophia Sonnewald is therefore pleased that funding for the research is planned for the relatively long duration of five years. She expects that their efforts will need to be continued after that as well. Indeed, it is quite possible that it may take several decades until all their breeding objectives are met. “However, this approach is still extremely important, not only for more environmentally friendly farming but also in view of climate change that requires varieties adjusted to suit the changing conditions,” she says.

Interdisciplinary consortium

The Bavarian State Research Center for Agriculture (Bayerische Landesanstalt für Landwirtschaft (LfL)), the Julius-Kühn-Institut (JKI) in Groß Lüsewitz near Rostock, the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) that is also based there and FAU are working together on the project with approximately one dozen partners from Mecklenburg-Vorpommern, Baden-Württemberg and Bavaria. The partners include seed producers, organic farmers and companies from the food industry. “Our consortium comprises the entire value added chain, starting from breeding to cultivation to processing the potatoes,” explains Adolf Kellermann from the LfL, who is coordinating the project. “This allows us to take into consideration not only the special quality requirements of organic farmers, but also those of the companies who process the potatoes further down the line.”

Those involved in the project hope to not only cultivate new varieties with as favorable properties as possible. “We are also interested in what causes these properties at the biological level,” underlines Sophia Sonnewald. “For example, if we notice that one of our varieties is particularly resistant to late blight, we would like to understand the mechanism behind it: which genes are responsible, and what exactly do they do? It is similar if we succeed in increasing the plant’s tolerance to heat or drought, or in improving how the plant processes nutrients.” The project may help to identify biological processes that may also be suitable for transferring to other crop plants.

Further information:

PD Dr. Sophia Sonnewald
Chair of Biochemistry
Phone: +49 9131 85 25239
sophia.sonnewald@fau.de