Scientists trace the evolution of cocoa to breed better chocolate
It's kind of hard to imagine life today without chocolate, and now we have a better idea of who we can thank for that. A team of researchers has traced back the origins of the cocoa tree to a single domestication event thousands of years ago, and uncovered other clues hiding in its genome that could help make future chocolate even better.
After the full genome of the Theobroma cacao plant was sequenced in 2010, researchers were able to use that as a starting point to study its evolution. The team on the new study sequenced 200 individual plants, and compared those to the archetype genome to paint a more complete picture of the history of cocoa.
Specifically, the team looked at Criollo, the first variation of cocoa to be domesticated. The analysis traced it back to a single domestication event in Central America around 3,600 years ago. That said, the bracket of possibility is quite wide – it could have been as recent as 2,480 years, or even earlier than 10,900 years.
The team says the Criollo cocoa originated in the Amazon Basin but was likely traded north to Central America, where the domestication process began. The original population was probably about 738 trees – although, again, a wide margin means it could have been as few as 437 and as many as 2,674.
The plant was selected and bred with a focus on improving its flavor, disease resistance and the amount of theobromine, which is a stimulant. Unfortunately, it wasn't all positive traits though, and genes that reduced crop yields also slipped through into modern Criollo cocoa.
That might partly explain why Criollo isn't commonly consumed nowadays – the variant accounts for only five percent of the world's cocoa production. It is, however, considered to be tastier than Forastero, the variant most common in commercial chocolate. A better understanding of the genetics of these plants can help growers create better breeds that ideally combine the best traits from different variations.
"What we would like to have is a way to combine plants from populations with high productivity – like Iquitos – with plants of Criollo origin, while retaining all these desirable traits that make Criollo cacao the best in the world," says Omar Cornejo, lead author of the study.
And really, nobody is going to complain about more innovation in the chocolate industry. In recent years, we've seen new additives and production techniques that can produce healthier and better-tasting chocolate, and even entirely new types like the strikingly-pink ruby chocolate.
The research was published in the journal Communications Biology.
Source: Washington State University