This is how corn was born

The subject has been debated for a long time. We now know that the key event took place 5,000 years ago, on the American continent: a teosinte (a grass already cultivated there) hybridized with another, to produce an even more vigorous and nourishing plant. , from which all current corn plants descend.

It is the story of an improbable encounter that changed the face of the world – knowing that hybrid vigor remains today at the heart of approaches to creating new varieties of corn. Hervé Poirier, editor-in-chief of the scientific magazine Epsiloon, explain to us today we finally understood how corn was born.

franceinfo: The key moment would have taken place around 5,000 years ago, in the plains of Mexico?

Hervé Poirier: It is the first cereal cultivated in the world, ahead of rice and wheat. It has long been the staple food of Native Americans. But’origin of corn seemed a bit magical. What is this plant that is unlike any other, made up of a long stem, with heavy ears, filled with immense grains?

Where does this botanical monster come from?

After numerous hypotheses, and numerous controversies, a consensus gradually emerged around a plant which is normally shaped like a bushthere teosinte.

This was demonstrated in 2011: iAbout 10,000 years ago, on a plain in Mexico, a teosinte plant underwent a mutation in a gene, which transformed it into a long stem, with grains stacked into pods. And this primitive form of corn began to be domesticated in Central America. But that wasn’t the end of the story.

By analyzing more than 1000 different corn and teosinte genomes, a team of around thirty geneticists, mainly Chinese, has just demonstrated that the key moment in fact took place afterwards, during a hybridization undergone by this mutant teosinte, 4 to 6,000 years ago.

A hybridization? That is to say a cross with another species?

Yes, with another form of teosinte, adapted to the altitudes, which had kept its bush shape. And this random encounter was magical: LThe hybrid that was born from it formed a stem-shaped plant, even more vigorous and nourishing, with larger ears, and enriched nutritional content. Better: this hybrid flowers earlier, which makes it adapted to cooler and more varied climates than the plains of Mexico. In short: a monster was born.

And he prospered…

Nothing could stop the monster. It is this hybridization that allowed corn to disperse beyond Central America, to invade the entire northern and southern continent. Then Christopher Collomb imported it in 1493 to Europe.

Over the course of hybridizations, this time artificial, farmers and seed companies have continued to produce new varieties of corn. But yes: all corn plants grown today descend from this original hybrid. All come from this improbable meeting between two teosintes, 4 to 6,000 years ago, in the heights of Mexico. A meeting that changed the face of the world.