New genetic map could make your morning coffee more climate resilient

A new genetic map of the Arabica coffee plant, Coffea arabica, could help breeders develop more climate-resistant brews.

Coffee is the second most consumed beverage on Earth, with more than 2 billion cups enjoyed every day. It’s also a valuable commodity: in 2023, the global market was worth more than US$93 billion (£74 billion).

With their superior mild taste and many fine varieties, Arabica coffee beans account for approximately 60-70% of global coffee production. Coffee farming also directly supports the livelihoods of 25 million family farmers and an additional 100 million people involved in coffee processing and retailing.

But coffee crops are also threatened by climate change in many parts of the world and we need to use breeding to help crops adapt to new conditions and grow them in areas less sensitive to factors such as Drought.

Published in Natural communications, this study could help produce coffee varieties with higher yields and greater resilience to climate change. This new knowledge could not have come at a more important time for coffee culture.

Secrets of Coffee Genetics

The landmark study by an international group of scientists has revealed the surprising genetic factors underlying the diversity of the hundreds of Arabica coffee varieties grown around the world. The new work, led by a team from the University of Udine, Italy, also reveals surprising similarities between the genetics of coffee and other important crops, including potatoes, brassicas and wheat.

These crops are known as tetraploids because they have four copies of each gene, instead of the two copies (one from each parent) found in humans and almost all other animals. As shown below, the Arabica genome contains eleven groups of chromosomes each containing two copies of each of its respective parents, Coffea canephora in blue and Coffea eugenioides in green. In some cases, parts of the blue and green chromosome segments have mixed together.

Unlike edible crops such as wheat or potatoes, which have undergone extensive breeding over decades, even centuries, to create drought-tolerant or pest-resistant varieties, coffee is lags behind in the application of modern breeding methods.

This includes the use of more precise DNA-based techniques, such as genome editing which involves making changes to the DNA. These methods, also used in medicine, make it possible to precisely identify and manipulate parts of a crop’s genome or genetic code to improve many aspects of its performance.

With more detailed information about the genetic makeup of coffee, researchers can begin to use these methods to improve coffee varieties. One of the problems with Arabica coffee is that our current varieties are not very diverse.

However, there are many very diverse wild coffee species and one goal will be to generate more resilient hybrids between wild and cultivated species. This will allow breeders to produce a wider range of coffee varieties that could thrive in many parts of the world.

Climate-resistant coffee?

In 2022, a Swiss study showed that Arabica coffee crops face unprecedented threats from climate change that could seriously affect major producing regions like Brazil and Ethiopia. Parts of these regions may become unsuitable for coffee cultivation due to increased incidence of drought and threats from new pests or diseases.

Breeders are already applying advanced methods to develop other drought-tolerant crops. In the future, these technologies could be applied to coffee. Indeed, previous work in Portugal and Latin America has already shown that new hybrid varieties from East Timor exhibit useful disease resistance and a form of increased vigor called heterosis.

This new knowledge will expand the ability to produce new coffee hybrids that are suitable for regions such as India and New Caledonia, where they could be a new crop for farmers.

As coffee crops face significant threats from climate change, it is encouraging that we are now able to understand the marvelous genetic complexity of coffee plants in unprecedented detail. New genetic knowledge could also lead to the development of new flavors that would further diversify the appeal of coffees in different regions of the world.

With the development of more precise breeding tools to produce more resistant varieties, coffee could be at the dawn of a new era for both farmers and consumers.

This article is republished from The Conversation under a Creative Commons license. Read the original article.