[SciTech+] "Potatoes evolved from tomatoes in South America 9 million years ago"

(Seoul=Yonhap News) Reporter Lee Ju-young = A study has revealed that potatoes, a globally important food crop, evolved from a natural hybridization between a wild tomato plant and a potato-like plant in South America about 9 million years ago.

An international research team led by Dr. Sanyuan Huang of the Chinese Academy of Agricultural Sciences (CAAS) announced on the 1st in the scientific journal Cell that they analyzed the genomes of 450 cultivated potatoes and 56 wild potatoes, and discovered that a natural hybridization between the tuber-less potato-like plant Etuberosum and a tomato occurred in South America about 9 million years ago, leading to the emergence of the potato plant.

Dr. Huang said, "We have finally solved the mystery of where the potato came from," and added, "This research result shows how hybridization between different species can trigger the evolution of new traits and lead to the emergence of more species."

Although the potato is one of the most important crops in the world, its origin has not been clearly identified. The appearance of modern potato plants is almost identical to that of potato-like species called Etuberosum found in Chile, but Etuberosum species do not have underground tubers and are more closely related to tomatoes phylogenetically than to potatoes.

To uncover the evolutionary secrets between modern potatoes, Etuberosum, and tomatoes, the research team analyzed and compared the genomes of 450 cultivated potatoes and 56 wild potatoes.

The results showed that both cultivated and wild potatoes contain a stable mixture of genetic material derived from both Etuberosum and tomatoes within their genomes, suggesting that potatoes originated from an ancient hybridization between the two species.

Using a molecular clock model to estimate the evolutionary timing of each plant, the results showed that Etuberosum and tomatoes, although different species, had a common ancestor about 14 million years ago.

The research team found that Etuberosum and tomatoes were able to interbreed for about 5 million years even after they evolved separately, and during this breeding process, potatoes with underground tubers emerged about 9 million years ago.