Gene Discovery Explains How Tomatoes Shaped Today’s Potatoes

Potatoes are a global staple, enjoyed fried, mashed, baked, and beyond. But few people realize that this humble tuber owes its very existence to an ancient partnership with tomatoes.

Scientists now reveal that key potato genes originated through a nine-million-year-old hybridization, offering new insights into crop evolution.

A Surprising Hybrid: Tomato Meets Etuberosum

Deep in South America, about nine million years ago, a rare union occurred between a wild tomato and a potato-like plant called Etuberosum. This event created the ancestor to every potato we eat today, reshaping plant evolution and, eventually, human diets.

Modern potatoes look similar to Etuberosum, but only potatoes form tubers, the underground food storage organs we rely on. Scientists were puzzled: why could potatoes grow tubers when their close wild relatives could not?

Did you know?
The potato, the world’s third most important staple food, is a direct genetic descendant of an ancient tomato hybridization event nine million years ago.

Decoding the Potato Genome

To solve this mystery, an international team analyzed DNA from over five hundred potato and wild relative specimens. Their research found every potato species contained a significant genetic mix from both wild tomatoes and Etuberosum plants.

This hybridization brought together genes never previously combined, enabling the evolution of the unique features of the modern potato. It’s the biggest genetic study ever conducted on potato origins.

Two Genes, One Breakthrough

The breakthrough came down to two crucial genes. The first, called SP6A, comes from the tomato background. It acts as a master switch, telling the plant when to form tubers. The second gene, IT1, originated in Etuberosum and guides the development and swelling of underground stems into actual tubers.

Without both genes, potatoes wouldn’t have their trademark tubers. This genetic combination was possible only because of the ancient hybridization. Modern potatoes carry both, enabling crops across the world to feed billions.

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The Andes and a Burst of Evolution

Timing was everything. The potato-tomato hybridization happened during the rapid geological uplift of the Andes mountains, which created many new environments and ecological niches. With their nutrient-storing tubers, potatoes gained a survival edge, enduring harsh mountain climates and spreading faster than other plants.

Tubers gave potatoes a reproductive superpower, too. Instead of relying solely on seeds or pollination, potatoes could sprout new plants directly from tuber buds, helping populations expand rapidly.

Adaptive Radiation and Global Domination

Equipped with their novel genes, potato ancestors quickly adapted to the wide range of climates across Central and South America. Over time, this led to the emergence of more than a hundred distinct wild potato species, all part of the Petota group, and paved the way for worldwide cultivation.

Scientists call this process adaptive radiation. A single genetic innovation like tuber formation enabled potatoes to colonize new habitats, diversify rapidly, and ultimately become an agricultural mainstay.

Why Gene Discovery Matters Now

Potatoes rank as the world’s third most important staple crop, nourishing billions. Understanding their genetic past isn’t just academic; it’s practical. This new knowledge can help develop disease-resistant, more nutritious, and higher-yield potato varieties critical for future food security.

Researchers say this story also underscores the power of hybridization in the natural world. Combining forces among species unlocks entirely new traits, transforming not only individual crops but also entire ecosystems and human societies.

Language and Legacy

The connection between potatoes and tomatoes extends beyond the realm of science. The words themselves share roots: “tomato” evolved from the Nahuatl “tomatl,” entering Spanish as “tomate,” and then English, mirroring how “potato” journeyed through Spanish (“patata”) and into English. Language itself holds clues to this ancient relationship.

This discovery marks a major leap in our understanding of crop origins. Next time you enjoy potatoes, remember: each bite reflects a genetic story nine million years in the making, all set in motion by a chance encounter between two wild plants.