Improving resilience of Arabica coffee plantations by cultivating F1 hybrid varieties: challenges to future seed production and enhancing farmers' access to modern varieties.

The production of F1 hybrid Arabica varieties is a key strategy to improve the resilience, competitivity and sustainability of coffee cultivation. Indeed, under both full sun and agroforestry systems, these varieties have performed better than traditional varieties in terms of higher yields, cup quality, and enhanced tolerance to biotic and abiotic stresses, including remarkable adaptation to the shady conditions of agroforestry. Until recently, somatic embryogenesis was a key cloning methodology that made it possible to start propagating the first selected F1 hybrid. However, this in vitro method of multiplication is complex and costly, technically demanding and hence limited to a few high-tech micropropagation laboratories. Horticultural vegetative propagation techniques such as rooted mini-cuttings have been developed to reduce the cost. They provided a scalable solution for larger-scale dissemination by spreading it across numerous regional nurseries at less cost but still too high, thereby contributing to the popularization and adoption of F1 hybrids. More recently, a major innovation for the global coffee sector was the arrival of new Arabica F1 hybrids with similar agronomic performances but produced by seed and using male sterility. The cost of seed propagation is low, similar to the production of seedlings of conventional pure lines plus seeds are easy to disseminate, while clonal methods ensure total genetic uniformity so, depending on the production goals, local constraints and the target market, the two approaches may be complementary. This methodological paper focuses specifically on F1 hybrid Arabica coffee seed production. Changes to breeding strategies and the different propagation techniques used to develop and disseminate F1 hybrid varieties are described, together with the advantages and limitations, with emphasis on biotechnological approaches, horticultural clonal propagation methods and recent advances in male sterility systems. Technical aspects aimed at improving the use of seed gardens and optimizing hybrid seed production in coffee are reviewed. F1 hybrid seed technology represents a promising development for coffee breeding and propagation, allowing access to high-performing and more resilient cultivars, hence supporting farmer's transition toward climate-smart and sustainable coffee production systems.