Potato evolved from tomato: Scientists solve 9-million-year mystery of its origin

Potato Evolved from Tomato (Image: Canva)

Have you ever wondered where the humble potato came from? A team of international scientists believes they’ve finally cracked the mystery. Their findings suggest potatoes were born from a natural plant mix-up nearly 9 million years ago.

Tomato Hybrid May Have Created First Potatoes

According to a new study in the journal Cell, potatoes likely emerged after a wild hybridisation between ancient tomato plants and Etuberosum species in South America. This genetic blending may have triggered the evolution of tubers—the underground storage units that define potatoes.

Researchers believe the crossbreeding happened even after the two parent plants had split apart millions of years earlier. Though Etuberosum plants look like potatoes, they don’t grow tubers. Instead, scientists found the key potato genes came from both sides of the family tree.

Tuber-forming and non-tuber-forming species of the potato plant. (Image: Yuxin Jia and Pei Wang)

What Genes Helped Potatoes Grow Tubers?

The research team, led by China’s Agricultural Genomics Institute, studied 450 genomes from cultivated potatoes and 56 wild species. They discovered a stable mix of genes from both Etuberosum and tomato plants in every potato sample.

One critical gene, SP6A, came from the tomato lineage. It tells the plant when to form tubers. Another gene, IT1, which helps tubers grow underground, came from the Etuberosum side. Without both, the modern potato would not exist.

When and Where Did It All Happen?

This hybridisation event is believed to have occurred around the time the Andes Mountains began rising rapidly. As the environment shifted, so did the vegetation. The tuber gave potatoes an edge in this new landscape, allowing them to endure harsh weather and thin atmosphere.

Potatoes do not have seeds to propagate like most other plants. They can produce new potatoes directly from their tubers. This quality allowed them to rapidly colonise varied landscapes in Central and South America.

Why Is This Discovery Important Now?

The potato is today one of the globe's most significant food crops. But until now, its origin was unclear. In appearance, modern potatoes resembled Etuberosum species, but genetically they were closer to tomatoes. This research has finally bridged that gap.

“Evolving a tuber changed everything for the potato,” said Sanwen Huang, one of the lead authors. “It helped them thrive in tough environments and led to a variety of species we depend on today.”