At a Glance
- Researchers discovered the potato lineage originated from a natural hybridization event between tomato-like and potato-like species that occurred approximately 9 million years ago in South America.
- Comprehensive analysis of 128 potato genomes revealed that all modern species contain a stable, balanced mix of genetic material from these two distinct ancestral lineages.
- The evolution of the potato’s tuber was a direct result of this hybridization, combining a key “on switch” gene from the tomato ancestor with a growth gene from the other.
- This new trait provided a significant evolutionary advantage, allowing early potatoes to store nutrients and survive the harsh, changing environments created by the rising Andes mountains.
- The ability to form tubers, combined with asexual reproduction, triggered a rapid diversification of potato species, allowing them to spread and occupy a wide range of ecological niches.
An international team of researchers has solved the long-standing mystery of the potato’s origin, revealing that the staple crop arose from an ancient hybridization event. In a study published in the journal Cell, scientists demonstrate that approximately 9 million years ago, a tomato-like plant and a wild, tuberless potato relative interbred. This natural cross-pollination gave rise to the entire potato lineage, known as Petota, and triggered the evolution of its most defining feature: the underground tuber.
To uncover this evolutionary history, scientists conducted the most comprehensive genomic analysis of wild potatoes to date, sequencing 128 genomes from cultivated and wild species. Their findings showed that every potato species carries a stable mix of DNA from two distinct ancestral groups: the tomato lineage and a non-tuber-bearing wild potato group called Etuberosum. This mixed ancestry, a result of a process called interspecific hybridization, was the crucial first step. “Our findings show how a hybridization event between species can spark the evolution of new traits, allowing even more species to emerge,” said corresponding author Sanwen Huang of the Chinese Academy of Agricultural Sciences, in a journal press release.
The formation of the tuber itself was a direct result of combining genetic material from both parents. Researchers identified key genes responsible for tuberization, the process by which a plant forms a tuber. The “master switch” gene, which tells the plant when to start storing nutrients, is called SP6A and originated from the tomato ancestor. Meanwhile, another critical gene, IT1, which controls the growth of the underground stems that become tubers, was inherited from the Etuberosum parent. Without this precise combination of genes, the potato would be unable to form its signature tuber.
This evolutionary innovation gave the ancient potato a decisive advantage. The development of the tuber coincided with the rapid uplift of the Andes mountains, which created new and harsh ecological environments. With its underground nutrient storage, the early potato could survive cold weather and poor conditions. This trait, along with the tuber’s ability to sprout new plants asexually, fueled an explosive diversification, allowing the potato to rapidly spread and adapt into the more than 100 wild species found today across Central and South America.
References
- Cell Press. (2025, July 31). Modern-day potato originated from hybridization event with tomatoes 9 million years ago, study reveals. Phys.Org; Cell. https://phys.org/news/2025-07-modern-day-potato-hybridization-event.html
- Zhang, Z., Zhang, P., Ding, Y., Wang, Z., Ma, Z., Gagnon, E., Jia, Y., Cheng, L., Bao, Z., Liu, Z., Wu, Y., Hu, Y., Lian, Q., Lin, W., Wang, N., Ye, K., Wang, H., Zhang, J., Zhou, Y., … Huang, S. (2025). Ancient hybridization underlies tuberization and radiation of the potato lineage. Cell, S0092867425007366. https://doi.org/10.1016/j.cell.2025.06.034
