Potatoes and tomatoes share a surprising history

Today’s potatoes arose retired of an improbable mashup — with a tomato.

Until now, the potato’s root and evolution had agelong been a technological mystery. It present appears that the starchy spud emerged 9 cardinal years agone arsenic the Andes Mountains were forming. It came astir from earthy breeding events betwixt an aboriginal herb works and a potato-like species.

This ancient transverse gave emergence to the plant’s swollen stem parts, known arsenic tubers. Tubers yet dispersed done immoderate 180 chaotic taxon of potatoes and thousands of cultivated varieties. Scientists from astir the satellite shared the caller findings successful the September 18 contented of Cell.

Digging into potatoes

The cultivated murphy — Solanum tuberosum — is 1 of the world’s astir important staple foods. Scientists knew it was related to Solanum etuberosum, a South American plant. That taxon looks a batch similar our murphy plant. It conscionable can’t signifier tubers, those parts that we crook into fries, baked potatoes and chips.

Genetics had shown that potatoes are related to tomatoes. But scientists thought the 2 plants were similar distant cousins. Instead, probe present shows, species from these 2 lines interbred.

The squad peeled backmost the potato’s root by analyzing dozens of chaotic and cultivated varieties of potato. About fractional of the genes successful each murphy taxon traced to the tomato, the remainder to S. etuberosum.

This suggests potatoes came from a azygous hybrid transverse of these 2 groups, says Sandra Knapp. She’s a botanist astatine the Natural History Museum successful London, England.

“In creating that hybrid offspring, assorted cistron families came unneurotic and interacted to alteration the instauration of tubers,” she says.

One cistron — SP6A — came from the herb side. Previous studies had shown it works arsenic a maestro power for tuber initiation. Another cistron — IT1 — is cardinal to the maturation of underground stems that signifier tubers. It came from S. etuberosum.

Experiments successful murphy plants present confirmed that without the IT1 gene, tubers are tiny. Without SP6A, tubers don’t adjacent form.

How combining these genes successful 1 works “led to potatoes making potatoes isn’t afloat explained successful this paper,” says Salomé Prat. She’s a works biologist who did not instrumentality portion successful the caller study. She works astatine the Centre for Research successful Agricultural Genomics. That’s successful Barcelona, Spain. Showing that these genes came unneurotic from a earthy transverse does not mean tubers formed close away, she adds. “The communicative is overmuch much complicated.”

A much resilient spud

How interbreeding led to tubers shows that hybrid crosses tin beryllium a almighty operator of evolution. Some caller hybrids tin beryllium sterile (unable to reproduce). But tubers store h2o and nutrients. And if near buried, they tin sprout caller plants. No pollination oregon seeds are needed.

This apt gave the caller murphy lines clip to regain an quality to reproduce sexually. And the caller tuber structures whitethorn person fixed aboriginal murphy plants an borderline arsenic the Andes began to signifier millions of years ago.

Tomatoes similar dry, lukewarm conditions. S. etuberosum thrives successful cold, bedewed places. Potatoes inherited a premix of traits that allowed them to flourish adjacent successful cold, adust sites. They got “the champion of some worlds,” Knapp says. And changing habitats successful the Andes mightiness person fixed these caller taxon opportunities to thrive.

Most of today’s 180 chaotic murphy taxon are bitter oregon toxic. But galore thousands of years ago, Indigenous radical successful the Andes recovered a tasty chaotic potato. Over time, they developed galore varieties from it. Spanish explorers aboriginal brought respective of them to Europe. This led to the potato’s planetary dispersed arsenic a nutrient staple.

More recently, scientists and farmers person crossed murphy taxon to get traits specified arsenic precocious output oregon pathogen resistance. Many of these mislaid immoderate of the potato’s archetypal familial variability. That makes today’s potatoes little adaptable — and much susceptible — to utmost heat, flooding and different features...