The mystery of potato evolution has been solved—and it involved a tomato.
The potato is a global
food staple. It was first cultivated thousands of years ago in the Andes of
South America before it spread worldwide starting in the 16th
century. But its evolution has long been a puzzle, until a recent analysis
finally unraveled its origins.
Scientists say that the
potato lineage emerged approximately nine million years ago in South America,
through a natural interbreeding event between a wild tomato plant and a
potato-like species. This discovery is based on the genomic analysis of 450
cultivated types of potatoes and 56 wild species.
This ancient
hybridization event led to the appearance of the potato plant’s distinctive
tuber—the enlarged structure housing nutrients underground. While the edible
part of a tomato plant is its fruit, the potato’s value lies in this
subterranean growth. Researchers also identified two crucial genes involved in
tuber formation, which deepens our understanding of this crop.
Potatoes are one of the
most remarkable food staples, combining versatility, nutritional value, and
cultural ubiquity. Around the world, people eat potatoes using virtually every
cooking method. Although stereotyped as carbohydrates, potatoes offer vitamin
C, potassium, fiber, and resistant starch. They are gluten-free, low-fat, and
satiating. They are a nutrient-dense calorie source.
Resistant starch is a
type of carbohydrate that resists digestion in the small intestine and ferments
in the large intestine. This means it feeds beneficial bacteria in the gut.
The scientific name for
modern a potato plant is Solanum tuberosum. Its two parents were
ancestors of a potato-like species now found in Peru named Etuberosum
(which closely resembles the potato plant but lacks a tuber) and the tomato
plant. These two plants shared a common ancestor that lived about 14 million
years ago, so they were able to interbreed when the hybridization event
occurred five million years after they had diverged.
The hybridization led
to genes being reshuffled so that the lineage produced tubers, which allowed
these plants to expand into the cold, dry habitats of the rising Andes mountain
chain. During the rapid uplift of the Andes, the potato plant could adapt to
the changing environment and thrive in the harsh conditions of the mountains.
The tubers stored nutrients for cold adaptation and enabled asexual
reproduction to counter the reduced fertility in cold conditions. Therefore,
the plant could survive and rapidly expand.
The study’s findings
may improve cultivated potato breeding to address environmental challenges that
crops presently face. There currently are roughly 5,000 potato varieties.
Potatoes are the world’s third most important food crop for humans, after rice and
wheat. China is the world’s leading potato producer.
It is hard to remove
all harmful mutations in potato genomes when breeding, but this study may show
how to make a potato free of harmful mutations using the tomato as the chassis
of synthetic biology. It may also lead to a new crop species that would produce
tomato fruit above ground and potato tubers below ground.
The potato and tomato
belong to the nightshade family of flowering plants, which also includes
tobacco and peppers, among others. The study did not investigate the evolution
of other tuberous root crops that originated in South America such as the sweet
potato and yuca, which belong to different families of flowering plants.
Although the parts of
the tomato and potato plants that people eat are quite different, the plants
are very similar. If you look at the flowers or leaves of these plants, they
are very similar. And if you let your potato plant produce fruits, those fruits
look like little green tomatoes. But don’t try to eat them; they are pretty
yucky.
https://www.msn.com/en-us/news/technology/the-mystery-of-the-first-potatoes-has-finally-been-solved-and-a-tomato-was-involved/ar-AA1JJN5G?ocid=hpmsn&cvid=a1e7bc6999b149a6a70e4275bd5155de&ei=68