Researchers from Germany have completely decoded the complex genome of the potato. This will make it easier and faster to breed new and more robust varieties, the Max Planck Society announced on Thursday in Munich. This is an important step for global food security.
Scientists from the Ludwig Maximilian University (LMU) in Munich and the Max Planck Institute for Plant Breeding Research (MPIPZ) in Cologne were involved in the project.
The study analyzed the genomes of individual pollen grains, which are normally collected by bumblebees for pollination. While traditional potato varieties that existed more than a hundred years ago are popular, this highlights a lack of diversity among the dominant varieties.
“Potatoes are increasingly becoming part of basic nutrition around the world,” explained geneticist Korbinian Schneeberger from the MPIPZ. The tuber is also gaining more and more influence in Asian countries. Potato varieties that are more productive and resilient to climate change could have a “huge impact on global food security in the coming decades.”
The low diversity makes potato plants susceptible to diseases. This was particularly evident during the Irish famine of the 1840s. Almost the entire potato crop was still spoiled in the soil for years because only a single variety was grown. This was not resistant to the newly emerged blight.
In the 1950s and 1960s, plant breeders succeeded in significantly stabilizing the yields of staple foods such as rice and wheat. However, there was no comparable development with the potato.
According to the researchers, the reason for this is the complex genetics of the potato. Instead of inheriting one copy of each chromosome from both father and mother, as in humans, the potato inherits two copies of each chromosome from each parent, resulting in four copies of each chromosome.
This also means four copies of each gene, making it very difficult and time consuming to create new varieties with a desired combination of individual traits. The reconstruction of the potato genome was therefore significantly more challenging than in humans.
For this reason, the researchers led by Schneeberger analyzed the genomes of individual pollen cells. In contrast to leaf tissue, these contain only two copies of each chromosome, which made reconstruction easier.
With knowledge of the complete DNA sequence of the potato, it is now easier to identify gene variants responsible for desired or undesired traits in order to include them in or exclude them from breeding.