Decoding the Flavour Diversity, Disease Resistance, and Climate Adaptation of the World's Most Beloved Coffee Species
A study released in the journal Nature Communications has provided the most complete sequencing yet of the genome of Coffea arabica, which currently represents around 60% of global coffee production. Its results are remarkable, shedding light on the variations in C. arabica that impact flavour profiles and disease resistance. But what can these findings tell us about cultivating this exceptional plant?
C. arabica, or Arabica coffee, is enjoyed around the world for its sweet, soft flavour and caffeine content. With an estimated 13.5 to 19.5 billion individual wild plants, you’d be forgiven for thinking that this crop is thriving. However, despite its huge wild population, it is classed as an endangered plant on the IUCN Red List because of its vulnerability, particularly to events like deforestation and climate change. As a crop with immense economic and social value, C. arabica holds global importance, and the ramifications of widespread yield decrease would be disastrous.
Thankfully, the research by Scalabrin, S., Magris, G., Liva, M., et al. has revealed a number of elements that cause diversity in this species. This diversity is most obvious in differences in flavour profiles, but there are also mutations that cause disease resistance; in particular, some variations may provide insights into resistance against coffee leaf rust (CLR), which can stunt photosynthesis in plants, leading to low foliage and yield sizes. Eventually, the disease can deplete the plant’s resources to the point where it can no longer survive. In 2012, CLR swept Latin American and Caribbean countries, leading to an epidemic of crop losses that the USAID estimated to be worth $1 billion. Although lessons were learned from this rust epidemic, the vulnerability of C. arabica to the disease means that a similar situation could lead to disastrous results for farmers in the future. If this new research can provide insights into the genetic variations that provide resistance to CLR, the implications for genetically-modified coffee could potentially be huge.
Another big vulnerability for C. arabica is climate change. This crop is sensitive to changes in heat, so an increase in global temperature and extreme weather events could see its population dwindle. In fact, some studies estimate as much a half the land used to cultivate coffee could become unproductive by 2050, with species like Coffea stenophylla potentially becoming the dominant coffee due to its heat-tolerant nature. The recent study into C. arabica’s genome could help to inform coffee breeding programmes to select favourable characteristics that will make the plant more resistant to the changing climate, with the potential to create genetically-modified crops that can thrive at higher temperatures.
Ultimately, this study has provided some clear insights into the structure and evolution of C. arabica, but more work is now needed to provide clear, practical results for coffee breeders. Kassahun Tesfaye, a plant geneticist at the Institute of Biotechnology at Addis Ababa University, told nature.com that “we need to equip breeders, mostly in the developing countries, with the toolkits to breed for low caffeine, to breed for specific disease [resistance], to breed for high productivity.” The outcomes are closer now than ever, and with time, research and hard work, the future may be a little brighter for C. arabica.
Megan Diehl is a dedicated writer who loves to explore the world of food and agriculture, sharing insights that connect people to the roots of their sustenance. When she isn't writing, Megan can usually be found cooking for her family, creating textile art and gardening.
