By Emma Sage, SCAA
In late January of this year, World Coffee Research (WCR) gathered a group of coffee breeders and other interested parties to discuss the future of coffee cultivars in Central America. Representatives from WCR, SCAA, Anacafé, Promecafé, AGRITECH NST, CATIE, USAID, and CIRAD discussed the results of the WCR genetic diversity study, and decided a way forward for WCR’s pre-breeding and variety improvement projects. These projects aim to breed new coffees for a changing world, and will result in new coffee ‘varieties’ that WCR and partners will distribute all over Central America within the next decade.
Growing and enhancing the supply of Coffea arabica is core to the WCR’s mission. As an institution, it takes a multi-faceted approach to this ambitious goal. An important part of its strategy is the development of new coffees that can live and thrive in the future. This means coffees that are highly productive, resistant to various challenges, and have favorable cup quality. The WCR variety improvement and pre-breeding projects emphasize the need to increase genetic diversity within cultivated coffees globally, and to develop new coffees that will meet the needs of producers and the entire specialty market in the future.
The history of coffee breeding in Central America and around the world has been a story limited by genetic resources, and focused on increasing plant yield. Since the early 1900s, coffee has been bred in the Americas to meet the ever-increasing demand for coffee. Pest and pathogen resistances, drought tolerance, and quality have also been considered with varying success. In more recent history, breeders have created new “F1” populations, which are often crosses of American cultivars with wild-type Ethiopian landraces. These F1-generation plants are robust, but not genetically stable to plant from seed.
The future of coffee, particularly specialty coffee, depends on the ability of coffee plants to thrive faced with the challenges of the future. These may include more rust or other pathogen outbreaks, warming temperatures, shifts in rainfall distribution, or something else not yet expected. The current genetic situation of C. arabica is very precarious in Central America, where coffee does not have wide genetic variation with which to combat those challenges. That means C. arabica will need more genetic diversity and lots of it! You can learn more about the importance of genetic diversity and the general genetic situation of C. arabica here. The WCR pre-breeding project was designed to identify wider genetic diversity from existing C. arabica collections, and create elite coffees that will be able to acclimate to harsh conditions and withstand many future adversaries.
To implement this, WCR has brought on Dr. Benoît Bertrand to lead the breeding programs through a special partnership with CIRAD. Dr. Bertrand led the breeders’ meeting in Guatemala this January. This specialized project group reviewed the current coffees available in the region, discussed their merits and disadvantages, and assessed their genetic pedigree and potential for breeding new coffee. The group then went on to discuss two diverse “ideotypes” of future coffees that would be bred by WCR and partners. The group also reviewed the results from the WCR genetic diversity study and used this to discuss specific breeding strategies with which to move forward.
For the genetic diversity study, WCR partnered with CATIE in Costa Rica to assess the genetic diversity of its famed collection of FAO (Food and Agriculture Organization of the United Nations) and other germplasm. WCR also recently partnered with Sana’a University in Yemen to include samples from Yemeni coffee collections. The Yemeni collection is a valuable addition to this project because Yemen was likely the first place to grow coffee outside of Ethiopia, perhaps some 1,500 years ago. This means that the coffee in Yemen potentially possesses unique or favorable genes. From these Yemeni coffees and the CATIE collection, WCR sought to find a large diversity of genes that could be utilized to breed new coffees and therefore diversify the now restricted genetics of C. arabica.
This work was completed in 2014 by NSG (Nature Source Genetics, a private company contracted to do this work). Samples were obtained from CATIE and other sources. In total, 781 accessions of C. arabica and other coffee species, largely from CATIE and Yemen, were analyzed. All genetic diversity analyses were run. Preliminary results indicate that all of the C. arabica coffees were remarkably similar, with 98.8% average genetic similarity. However, the “wild” genotypes had a much larger diversity than the cultivated coffees that were measured. In fact, the cultivars only represented 45% of the total genetic diversity found in C. arabica. This means that C. arabica is likely less diverse than other coffees, as well as other plant species. This also means that within this study, the wild Ethiopian portions of the CATIE FAO collection and the Yemeni collection were significant contributors to diversity. In fact, the Yemeni coffees were found to contribute unique genetic diversity not present in any of the FAO Ethiopian coffee collections.
To complete this work, a genotype database of the results was developed by NSG. This database, recently completed, provides WCR with detailed diversity indexes and defines the accessions that hold the most diversity. These diverse individuals, as defined by NSG, make up a “core collection” of genetic material that can be used by WCR and others for breeding. The recommended “core collection” of 100 of these coffees represents 90% of the entire genetic diversity of the larger collection. Over 50% of the diversity in this core collection is made up of the wild type Ethiopian FAO accessions and the Yemeni collections. In the future, WCR plans to plant this core collection in multiple locations to preserve these valuable genetic resources. It has already done just that by distributing this core collection to the Starbucks Alsacia Farm in Costa Rica, among other locations, where it can be grown and assessed for important breeding characteristics.
In the January meeting, it was agreed that WCR will have two new coffees come out of its breeding program. One is a dwarf, highly resistant C. arabica coffee, and the other is a tall, high-altitude-specific C. arabica plant with good productivity and partial rust resistance. Aiming for two different phenotypes specific to different environments is a way to make sure that a larger segment of coffee producers can benefit from the project. The potential parents for these two coffees were discussed in the January breeders’ meeting based on the WCR diversity study. They will be bred utilizing a combination of identified known cultivars and specific selections from the CATIE and Yemeni collections, which will serve to improve genetic diversity.
Once the breeding of these new coffees begins, green coffee will be collected as soon as the trees produce, in order to be tested for their beverage quality. The best individual hybrids will be selected on the basis of their yield, fertility, vigor, resistance, and quality. They will be cloned and then sent to participating countries in Central America for propagation and distribution. These new coffees will also be included in other WCR projects such as the international multi-location variety trial. This work will go on until about 2018-2020, when the first new coffees are expected to become available.
Emma Sage is SCAA’s coffee science manager. Before moving into the coffee industry, she completed degrees in ecology and botany, and dabbled in the wine industry. She enjoys learning all there is to know about the science of coffee (and more importantly, sharing it with you).