The tomato’s path from wild plant to household staple is much more complex than researchers have long thought. For many years, scientists believed that humans domesticated the tomato in two major phases. First, native people in South America cultivated blueberry-sized wild tomatoes about 7,000 years ago to breed a plant with a cherry-sized fruit. Later, people in Mesoamerica bred this intermediate group further to form the large cultivated tomatoes that we eat today.
But in a recent study, researchers show that the cherry-sized tomato likely originated in Ecuador around 80,000 years ago. No human groups were domesticating plants that long ago, so this implies that it started as a wild species, although people in Peru and Ecuador probably cultivated it later.
They also found that two subgroups from this intermediate group spread northward to Central America and Mexico, possibly as weedy companions to other crops. As this happened, their fruit traits changed radically. They came to look more like wild plants, with smaller fruits than their South American counterparts and higher levels of citric acid and beta carotene.
The researchers were surprised to find that modern cultivated tomatoes seem most closely related to this wild-like tomato group, which is still found in Mexico, although farmers don’t deliberately cultivate it.
Read more at The Conversation (Hamid Razifard and Ana Caicedo)