Breeding program milestones for 2015
Update to Breeding for the Future
The coffee industry cannot
single-handedly reverse climate change. Our best hope for sustaining the supply
of high quality coffee in the 21st century is to focus on making the coffee
plant more resilient. The creation of new, highly adaptable coffees, supported
by a vibrant new seed sector, will result in major global productivity and
quality gains in the next 10-20 years. In 2015, WCR achieved a number of milestones toward this goal.
WCR Core Collection
Through an analysis of 847 arabica strains from the CATIE genebank, WCR located the 100 most genetically diverse individuals. These plants, which we call the WCR Core Collection, will be used by us and others to develop new hybrids that combine maximum genetic diversity with high performance. The collection has been grown into seedlings, which will be planted on three research farms in Central America in 2016. It will form an essential new reservoir of genetic diversity for coffee breeders for decades to come.
Arabica genetic distance matrix
The data analysis used to create the Core Collection also allowed us to determine how genetically different the plants are from one another. This “genetic distance matrix” is an essential tool for creating more productive coffees. Generally in plant breeding, the greater the genetic distance between two parents of hybrid offspring, the more “vigorous” the offspring will be, a property known as heterosis. In coffee, heterosis frequently translates to productivity, uniformity, and better vegetative growth (prior work has shown productivity increases of 30-40%). Using the genetic distance matrix, WCR’s breeders can take existing high-performing coffees known for desired traits like quality (e.g., Geisha) or disease resistance (e.g., Obata), and locate mates that are genetically distant to maximize heterosis in the offspring. In prior
Regional, collaborative breeding programs around the world
Both the Core Collection and the genetic distance matrix were put into use for the first time in 2015 to create the next generation of F1 hybrids for Central America. WCR’s breeding team held a workshop in January with partners to determine what qualities are preferred for two new varieties—one compact, with high productivity (30-40% more than Caturra), resistance to coffee leaf rust, and high cup quality (as good as or better than Caturra), for elevations between 800 and 1200 meters; the other tall, with very high quality, productivity higher than Bourbon, and better tolerance of rust, for elevations above 1200 meters. In fall 2015, 50 crosses were made using established types including Geisha La Luisa, Obata, and Marsellesa. In 2016, the offspring will be germinated, transplanted, and observed for performance, including rust resistance and drought tolerance. Successful varieties may be released in as few as five years.
In 2015, WCR and CENICAFE entered discussions about building a collaborative coffee-breeding program for the region. WCR and CENICAFE want to develop a common agenda to do the following:
- Sequence the genomes of part of CENICAFE’s germplasm collection
- Evaluate the WCR Core Collection for coffee leaf rust resistance
- Develop new F1 hybrids well-adapted to Colombian growing conditions and highly resistant to coffee leaf rust and CBD
- Develop interspecific plants to be used in an international pre-breeding program
- Evaluate the quality of Geisha coffee in different Colombian locations
In October, WCR and the African Fine Coffees Association convened a meeting of coffee breeders and researchers from across the continent to jumpstart a collaborative coffee breeding program for the region. The researchers endorsed a plan to bring the WCR Core Collection to the Coffee Research Institute in Ruiru, Kenya, which volunteered to serve as a regional breeding hub. In 2016, WCR’s coffee breeders will meet with breeders from participating African countries to create a list of ideal characteristics for new cultivars, and then work with us to use the WCR Core Collection to create new crosses.
WCR is working to create a comprehensive database of genes and markers for important arabica coffee traits using the latest DNA technologies. Doing so will allow us to rapidly accelerate the development of new cultivars of coffee that can meet the challenges ahead. In December 2015, we initiated an important precursor of this work in Nicaragua, observing an F2 population of 350 coffee plants developed from a cross between MS1 and IAPAR59 to record how certain physical traits were or were not passed on from parent to child (phenotyping), and then sequencing the DNA from the same samples to associate the observed traits with genetic markers in the plants (genotyping). As we accumulate more of this kind of data, breeders will become able to select parent plants based on their genetic makeup (which is easy and cheap to screen for using leaf samples) instead of waiting three to four years for the plant to mature. This can cut in half the time it takes to develop new cultivars.
Adaptation to climate change
More crops worldwide are lost to drought and heat than any other stressors; drought is especially harmful to crops like coffee that require water for essential stages of their growth and development. Droughts have become more frequent in coffee regions in recent years, and are expected to increase in number and severity this century. Scientists expect global arabica production to decline significantly in the next 20 years. The development of cultivars that are tolerant to drought and associated heat stress is essential to holding off these declines. To that end, a postdoctoral fellow with WCR is working to identify how coffee responds to drought and heat stress in both field and lab conditions in Minas Gerais, Brazil. Another fellow is also working to identify key genes involved in drought and heat tolerance. Results so far show that approximately 1500 genes are involved in coffee’s response to heat stress. Some of these genes are good candidates for future studies in coffee breeding, especially those aiming at the production of drought- and heat-tolerant plants.