Numerous trials were conducted to characterize coffee varieties under different types of stress (high temperatures, drought, shade, etc.) with studies under controlled conditions (greenhouses and climate chambers) and field settings in 6 countries. The database aggregated almost 750 000 records from all trials. In order to visualise the biochemical related records, updates have been made for the MapMan visualisation tool, especially concerning the metabolic reactions involved in the production of the main compounds responsible for the quality of coffee. On-farm assessments were realized in more than 100 farms. The promotion of Business Driven Agroforestry Clusters (Clusters) was evaluated with respect to social, environmental and economic dimensions. The need for a global governance of coffee genetic improvement and collaboration practices was highlighted by broad surveys of the main actors of the sector. Some major specific results are worth highlighting:
In contrast to many other species, under elevated CO2 and combined heat/drought interaction, Coffea cultivars reinforced their photochemical capability, capacity for repair of enzymes and dynamics of chloroplast lipid profiles. However, the enzyme involved in CO2 fixation, RuBisCO, appear to be the most stress sensitive component and may become limiting factors in a context of CC. These traits will demand a special attention by breeders. Flowering was proved to be the physiologic factor most affected by shade, which explains why plants under shade produce less. There is a genetic variability in that allows the selection of genotypes well adapted to shade. Some hybrids showed a strong capacity to adapt to shade and full sun. A genomic selection model for phenotype prediction was built for coffee taking into account shade adaptation.
We found that the mechanisms underlying the differences in aroma quality between genotypes are strongly dependent on the elevation. An enzyme (terpene synthase) responsible for some quality aspects is strongly over-expressed in some genotypes, but only in high altitude.
Using both genetic and biochemical data, we could built up models which were efficiently predicting the performance of the hybrids and we expect it will allow to speed-up the breeding of Arabica varieties adapted to shade.
In assessments conducted on-farm, F1 hybrids gave 29-61% higher yield than traditional coffee varieties. However, farmers considered that accessibility of varieties had to be improved, both in terms of purchase costs, better hybrid accessibility and in terms of knowledge on how to manage the new hybrids.
BREEDCAFS identified central actors act as brokers across actors in the global research collaboration on coffee genetic. BREEDCAFS recommends to further strengthen a multi-resource approach to create a label named Uni.C.Tree to promote the Clusters.
