Mystery of the origins of the potato resolved by genetics

It turns out that the humble potato, it turns out that the product of an appointment between an old tomato plant and a less known South American line named Trance.

Trance Plants are often described as resembling a potato plant, with the exception of a crucial difference – they do not produce the starch -rich tubers that have made cultivated potatoes one of the most important foods in the world.

Sandra Knapp at the Natural History Museum in London and her colleagues studied genetics of three groups of plants in the genre Solanum:: PetotaWith 107 species, including cultivated potatoes (Potato)); the tomato group, with 17 species; And Trancewith three species. The three lines shared a common ancestor about 14 million years ago.

The team examined 450 genomes of cultivated potatoes and 56 species of wild potatoes and found that there was, in each of them, a regular mixture of tomatoes and Trance Genoa.

The results suggest that the potato line comes from a hybridization event between the ancestors of the tomato and Trance groups, probably about 8 million years ago in what is now Chile.

Knapp says that the hybridization event has allowed new combinations of genes to occur, creating innovations such as the growth of tubers. “This event has led to a reshuffle of genes so that the new line has produced tubers, allowing these plants to develop in cold and dry habitats newly created in the rising Andes,” she said.

This shows that hybridization is a “powerful force in the evolution of diversity”, explains Knapp.

“In fact, the parts of the tomato and the potato that we eat are different, but the plants themselves are quite similar,” she said. “If you lucky you get a potato plant that produces fruit, it’s a green bay similar to tomatoes – but don’t eat it, it has a terrible taste.”

Brett Sumserell in the botanical gardens of Sydney, Australia, which has not been involved in the study, affirms that new works provide complete evidence of the hybridization and radiation of subsequent species – something that has been lacking for this group of plant parents.

“The study also highlights the importance of protecting the relative species of wild cultures in order to better understand how cultures have evolved and are likely to adapt to challenges in the future,” explains Summell.

“Many parents of species such as potatoes are threatened with destruction of habitat and the impact of climate change.”