Defense of Coffee in Central America: searching for Super genes to Save Wild Coffee

In March, about 20 people, including the world's top coffee researchers, gathered at the Centre for Tropical Agricultural Research and higher Education (CATIE) in Turialva, Costa Rica, to discuss the uncertain future of coffee, the world's most popular beverage crop, in Central America.

The theme of the seminar was a very harmful agricultural disease: coffee rust, which is called Roya in local Spanish. Fungus infects coffee leaves and causes rust, preventing it from getting the sunlight necessary to grow. In the past few years, about half of the 1 million acres of coffee grown in Central America have been ravaged by rust and reduced coffee production in the region by about 20 per cent in 2012.

Unfortunately, this is just one of many crises facing coffee crops in the context of global warming. Benoit Bertrand, a geneticist and coffee breeding expert at the French Centre for Agricultural Development (CIRAD) in the Turialva Cafe, said: "most of the coffee varieties we now grow are not resistant to diseases and insect pests, nor to rising temperatures and other environmental threats caused by climate change."

Indeed, because of the lack of genetic diversity, which is a key factor determining the survival of species, coffee can neither adapt to extremely hot climates nor resist diseases. In fact, 70% of the world's coffee belongs to the same variety-small fruit coffee. Different species, producing areas and roasting methods determine the variety of coffee tastes, but it also confuses people's correct understanding of the genetic history of coffee. Almost all the coffee we drink now has been introduced from Ethiopia in recent centuries, and there are very few kinds of wild coffee.

Now, with regard to the urgent threat to the coffee growing industry, researchers have begun to use scientific means to fix it and save coffee.

The savior of the coffee world

Scientists worry that climate change and rust will have a huge impact on the coffee industry. Although spraying fungicides can inhibit rust, the price of this chemical agent is very high and can not eliminate those emerging strains.

Tim Schilling, a geneticist jokingly known as Indiana Jones of the coffee industry, oversees the World Coffee Research Organization. In his view, the use of genetics is the only feasible and long-term solution. First, he plans to start with adaptive mutations that already exist in the coffee gene pool, including small fruit coffee and other coffee varieties grown. Medium fruit coffee and small fruit coffee are the only two species of coffee crops at present, but due to different planting areas, they also derived a number of varieties, and brought certain regional genetic differences.

In Schilling's big plan, a relatively simple study has begun, that is, the introduction of coffee plants from different places, and then to see if the introduced coffee trees are growing better than in their place of origin. At present, scientists have found 30 coffee plants with the highest yield from 10 countries in the study.

But overall, using genetic mutations in existing coffee crops is not enough to save coffee crops. Because coffee crops grown for commercial purposes have little genetic difference with small and medium fruit coffee. By contrast, the genetic differences between wild coffee are amazing. Researchers have made the latest progress in sequencing the coffee genome, which, in Bertrand's words, is a vast collection of coffee genes in wild coffee. Therefore, Bertrand hopes to use this genetic encyclopedia to make coffee crops more adaptive, more productive and more delicious at the same time.

The United Nations Food and Agriculture Organization (FAO) Ethiopia Coffee Exhibition Park in CATIE is where these genetic differences converge. Nearly 10000 small fruit coffee trees are neatly planted on about 21 acres of land, not only from Ethiopia, but also from other parts of Africa such as Madagascar and Yemen in Asia.

Researchers are looking for genes that make coffee crops "stronger" to prevent rust infection and improve their drought and high temperature tolerance. To this end, Bertrand and Schilling are screening in order to find as many good characters as possible from as few plants as possible. "the next thing is to use these plants to hybridize the coffee varieties that we expect to be delicious, high-yielding and resistant to all the diseases we know so far," Schilling said. "

Search for supergenes

Schilling and his companions have a bigger ambition: to create an unprecedented "artificial small fruit coffee" that combines the delicious taste of small fruit coffee and the high yield of medium fruit coffee. Schilling's plan is to go back to where it all started-re-hybrid small fruit coffee. Small fruit coffee was originally made from a cross between medium fruit coffee and Okinioides coffee. Now, the focus of the work is to find patrilineal varieties whose genetic diversity is much higher than that of traditional small fruit coffee. In order to achieve this goal, their vision can not be limited to the existing gene pool, they must return to nature, in the vast expanse of wild coffee to find those key unknown genes.

There are about 125 kinds of coffee on the planet, each of which produces genetic mutations far beyond the small number of samples in the gene pool, let alone those that have not yet been discovered. It is only hoped that researchers will be able to find these undiscovered species as soon as possible before they become extinct.

Aaron Davis has been studying wild coffee since 1997. His series of findings show that wild coffee is widely distributed in the tropics, from Africa to Asia and even as far away as Australia. In Ethiopia, where small fruit coffee is currently the main producing area, small fruit coffee trees are densely grown in some forests. Davis believes that many of these wild coffee trees can be planted artificially.

However, like coffee crops, wild coffee faces many crises. 70% of wild coffee is at risk of extinction, 10% of which could disappear completely within 10 years. Land development is the biggest threat to wild coffee.

Davis is concerned that researchers spend too much energy on coffee varieties that have been preserved, while other wild varieties that may contain more important genes are dying out or are becoming extinct because of human damage to the environment.

The relevant policies implemented by the Government of Ethiopia are also worrying. As the origin of coffee, the country contains a large number of unique wild coffee populations, but the Ethiopian government has banned foreign researchers from collecting them. The researchers urgently hope that the country can relax its policy and lift the ban on these precious resources. At the same time, scientists will also make use of existing resources to actively carry out research work.

Race against time

Shortly after the establishment of the World Coffee Research Organization, coffee rust swept through Central America. In response to the disaster, Schilling decided to hold a small meeting in Guatemala to discuss possible countermeasures. As soon as the meeting plan was announced, a large number of applications were received.

Schilling's meeting also attracted the attention of the United States Agency for International Development. Because the collapse of the coffee industry in Central America could lead to an influx of immigrants into the United States, which is the concern of the United States government behind the United States Agency for International Development. The World Coffee Research Organization estimates that rust outbreaks in Central America in 2012 cost coffee growers as much as $548 million. If governments and research institutions continue to do nothing, the coffee industry in Central America could be completely destroyed by 2050.

Schilling believes that in the face of a series of threats such as rust, it is very necessary to establish a long-term coordination mechanism. Schilling's project, eventually funded by the United States Agency for International Development (USAID), will provide growers with new coffee provenances that are more adaptable to climate and more resistant to diseases and pests through a high-tech breeding program.

The epidemic of rust is just a rehearsal of the threats facing the global coffee industry, where already fragile coffee crops will be vulnerable to emerging diseases under the influence of rising temperatures and extreme weather. To survive the crisis, coffee crops must be more adaptable. As Brett Smith, president of the North Carolina counter-Culture Coffee Company, puts it, choosing the genes for coffee crops is like "a portfolio of securities with only a few stocks to choose from". Smith is full of confidence in Schilling and his research partners, even though the "battle for coffee" has only just begun.

Finally, the only doubt is whether the relevant research can be completed in time. "if these studies had been done 10 years ago, we would not have to face these thorny problems today." Rick Reinhart, executive director of the American Fine Coffee Association, one of Schilling's chief partners, said, "now, if we don't get to work, time will be even more tight, and coffee may not wait for tomorrow."