The humble potatoes we know today are not a “pure race”: they were born of the accidental crossing 9 million years ago, between an ancestor of tomatoes and a kind of now extinct wild flowers.
An international research team found that potatoes are the result of a accidental hybridization that occurred between an ancestor of the modern tomato and an extinct member of a group of wild flowers known as Trance.
NO PUBLISHED IN THE MAGAZINE Cellinvestigators suggest that this ancient evolutionary event triggered the formation of tuberthe increased underground structure that stores nutrients. found in plants such as potatoes and yams.
“Our findings show how a species hybridization event can trigger the evolution of new characteristicsallowing even more species to emerge, ”says Sanwen Huangresearcher at the Chinese Academy of Agricultural Sciences and corresponding author of the study.
“Finally we solved the mystery from which the potatoes came from“, Underlines Huang, in a statement published in.
Being one of the most important cultures in the world, the Origin of potatoes long Intrigated the scientists. In appearance, modern potato plants are almost identical to three species similar to chilecalls Trance. But these plants They have no tubers.
In fact, based on phylogenetic analysispotato plants are more intimatelyelapsed with the tomatoes.
To resolve this contradiction, the investigators team analyzed 450 cultivated potato genomes and 56 of wild potato species.
“Wild potatoes are very difficult to collectthat’s why this data set represents the most comprehensive collection of wild potato genomic data ever analyzed, ”says the first author of the article, Zhiyang ZhangResearcher at the Institute of Agricultural Genomics at the Chinese Academy of Agricultural Sciences.
The study authors found that all potato species contained a stable and balanced mixture of genetic material Both plants Trance as in tomatoes, which suggests that the potatoes originated in a hybridization old between the two species.
Although Trance and tomatoes are distinct speciesshared a common ancestor about 14 million years ago. Even after diverging for about 5 million years, managed to cross – and gave rise to the first potato plants with tubers about 9 million years ago.
The team too tracked the origins of key genes of potato tubers formation, which are a combination of genetic material of each parent.
Found that the gene SP6Awhich acts as a main switch that tells the plant when starting to do tubers, Came on the side of the family tomato.
Other Important gene, called it1which helps control the growth of underground stems that form tubers, came from Trance. Without either party, hybrid descent would be unable to produce tubers.
This evolutionary innovation coincided with the rapid emergence of the Andes mountains, a period when New ecological environments They were emerging.
Common Tuber to store nutrients in the undergroundthe first potatoes got adapt quickly to the change environmentsurviving the harsh climate in the mountains.
Tubers also allow potato plants to be able to reproduce without seeds or pollination: They grow new plants that simply spring from buds in the tuber.
This characteristic allowed them to expand quickly and fill in various ecological niches from temperate prairies to high and cold alpine in Central and South America.
“Winning a tuber gave the potatoes a huge advantage In strict environments, feeding an explosion of new species and contributing to the rich diversity of potatoes we see and on which we depend on today, ”concludes Huang.
