Love a potato? Thank a tomato

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CC-0. https://pixabay.com/illustrations/fries-potato-frits-food-9730607/
CC-0. https://pixabay.com/illustrations/fries-potato-frits-food-9730607/

The origin of potatoes has been a long running mystery, but now international scientists say DNA suggests spuds evolved from tomatoes around nine million years ago in South America. The team says natural interbreeding between tomato-like plants and potato-like plants triggered the formation of the tuber - the starchy potatoes we know and love today. Potatoes had proved puzzling because, in appearance, modern potato plants are almost identical to three potato-like species from Chile called Etuberosum, but these plants don't have any tubers. So, the team analysed the genetic code of 450 cultivated potatoes and 56 wild potatoes, finding that they all contained a mix of genetic material from Etuberosum and tomatoes.  That suggests they resulted from the two plant species hybridising long ago, the scientists say.  Developing tubers allowed potatoes to flourish, because they allow reproduction without seeds or pollination and act as food storage for the plants, helping them survive in harsh environmental conditions. This allowed potatoes to rapidly spread across Central and South America, the team says.

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From: Cell Press

Potato evolved from tomato 9 million years ago

An international research team has uncovered that natural interbreeding in the wild between tomato plants and potato-like species from South America about 9 million years ago gave rise to the modern-day potato.

In a study publishing in the Cell Press journal Cell, researchers suggest this ancient evolutionary event triggered the formation of the tuber, the enlarged underground structure that stores nutrients found in plants like potatoes, yams, and taros.

“Our findings show how a hybridization event between species can spark the evolution of new traits, allowing even more species to emerge,” says corresponding author Sanwen Huang of the Chinese Academy of Agricultural Sciences, China. “We’ve finally solved the mystery of where potatoes came from.”

As one of the world’s most important crops, the potato’s origin had long puzzled scientists. In appearance, modern potato plants are almost identical to three potato-like species from Chile called Etuberosum. But these plants do not carry tubers. Based on phylogenetic analysis, potato plants are more closely related to tomatoes.

To solve this contradiction, the research team analyzed 450 genomes from cultivated potatoes and 56 of the wild potato species.

“Wild potatoes are very difficult to sample, so this dataset represents the most comprehensive collection of wild potato genomic data ever analyzed,” says the paper’s first author Zhiyang Zhang of the Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences.

They found that every potato species contained a stable, balanced mix of genetic material from both Etuberosum and tomato plants, suggesting that potatoes originated from an ancient hybridization between the two.

While Etuberosum and tomatoes are distinct species, they shared a common ancestor about 14 million years ago. Even after diverging for about 5 million years, they were able to interbreed and gave rise to the earliest potato plants with tubers around 9 million years ago.

The team also traced the origins of the potato’s key tuber-forming genes, which are a combination of genetic material from each parent. They found the SP6A gene, which acts like a master switch that tells the plant when to start making tubers, came from the tomato side of the family. Another important gene called IT1, which helps control growth of the underground stems that form tubers, came from the Etuberosum side. Without either piece, the hybrid offspring would be incapable of producing tubers.

This evolutionary innovation coincided with the rapid uplift of the Andes mountains, a period when new ecological environments were emerging. With a tuber to store nutrients underground, early potatoes were able to quickly adapt to the changing environment, surviving harsh weather in the mountains.

Tubers also allow potato plants to reproduce without seeds or pollination. They grow new plants by simply sprouting from buds on the tuber. This trait allowed them to rapidly expand and fill diverse ecological niches from mild grasslands to high and cold alpine meadows in Central and South America.

“Evolving a tuber gave potatoes a huge advantage in harsh environments, fueling an explosion of new species and contributing to the rich diversity of potatoes we see and rely on today,” Huang said.

Multimedia

Non tuberous and tuberous potato species
Non tuberous and tuberous potato species

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conference:
Cell
Research:Paper
Organisation/s: Chinese Academy of Agricultural Sciences, China
Funder: This work was supported by Guangdong Major Project of Basic and Applied Basic Research (2021B0301030004), the National Natural Science Foundation of China (32488302), the Science and Technology Major Project of Xizang (XZ202402ZD0005), the National Natural Science Foundation of China (32422053 and 31590821), the National Natural Science Foundation of China (32301896 and 32422079), Occurrence data collection for the lineages used in this study was funded by the US National Science Foundation Planetary Biodiversity Inventory project ‘‘PBI Solanum: a worldwide treatment’’ (DEB- 0316614), Basic Research Center for Agricultural Frontiers and Interdisciplinary Sciences (BRC-AFIS), Innovation Program of Chinese Academy of Agricultural Sciences (CAAS-BRC-AFIS-2025-02), Agricultural Science and Technology Innovation Program (CAAS-ZDRW202404), and Shenzhen Outstanding Talents Training Fund.
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