Somatic-embryogenesis derived leaf-rust-tolerant clones of arabica coffee to deal with climate change

Abstract

The high-altitude coffee growing, Arabica, is likely subject to the global warming effect as they are prone to leaf-rust attacks at a higher temperature. It supplied 70% of world coffee production for its popularity concerning its delicacy and aromatic flavor. Utilization of, genetically, superior planting materials, i.e. leaf-rust-tolerant Arabica, has become an essential point, as may provide the potential solution to prevent the lost production due to leaf-rust attack. Andungsari 2K (AS 2K), S795, AS1, and Sigararutang are some of the potential leaf-rust-tolerant Arabica clones in Indonesia. Vegetative propagation by somatic embryogenesis may support the availability of superior plant materials quickly. The major aim of this experiment was to study the effect of different clones on germination step after the preliminary stage of direct-embryogenesis from leaf explants with combinations of medium between auxin (2,4-D) and cytokinin (2-ip). Embryo germination stage where embryoid was transferred to the germination medium consisting of MS medium without hormones. The results revealed that the growth location and texture of callus, as well as growth patterns and colour of embryogenic callus, were significantly influenced through the different combinations of medium and clones. The clone of S795 exhibits the highest embryo germination percentage of up to 100% within 8 weeks experiment period.