DNA sequencing has confirmed that a lot of the coffee you drink is from one of the least genetically diverse crops in the world, making it particularly vulnerable to extinction.
Arabica beans (Coffea arabica) make up about 60 per cent of the world鈥檚 coffee production. 鈥淎rabica is the most valuable and highest quality coffee, but it is severely endangered by climate change,鈥� says Simone Scalabrin at IGA Technology Services in Italy.
Scalabrin and his colleagues used whole genome sequencing to look at 736 samples of Arabica plants from Ethiopia and Yemen which had been stored in a coffee conservation centre in Costa Rica.
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We already knew that the Arabica genome is the result of the fusion of two species, C. canephora and C. eugenioides, but we didn鈥檛 know if the Arabica we consume today is from this event occurring several times, or just once.
The researchers found that the genetics of the various samples of Arabica they looked at were more than 99.9 per cent similar. This low genetic diversity suggests these plants are the result of a single random hybridisation event.
While the event may have occurred more than once, this analysis suggests only one of these lineages survived, which means that every Arabica plant today has a common ancestor 鈥� probably around 10,000 to 20,000 years old.
鈥淚t is one of the least genetically diverse plants in the world,鈥� says Scalabrin, and this makes it particularly vulnerable to climate change, pests and disease. 鈥淣ow is the time for breeding, breeding, breeding,鈥� says Scalabrin.
Aaron Davis at the Royal Botanic Gardens in London says that this study strengthens the argument for developing a new generation of coffee crops. 鈥淏ut the difficulty with cross-breeding is ensuring that the coffee retains its taste,鈥� he says.
Nature Scientific Reports
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