Induction of embryonic callus from several Arabica coffee varieties using a combination of plant growth regulator formulations

This study aimed to investigate embryonic callus formation in four Arabica coffee varieties (Andungsari 1, Orange Bourbon, Gayo, and Lini S-795), conducted at Politeknik Negeri Jember in two stages. The first stage is the induction of primary callus from leaf explants of four Arabica varieties in four combination concentratrion of 2,4-D and Kinetin using 1/2 MS+Vitamin B5 (Gamborg) as the base medium. The observed variables included: time of primary callus formation; fresh weight; texture and callus color. The next experiment was to test four Arabica varieties for their regeneration capacity for embryonic callus formation. This study used a non-factorial completely randomized design, with four treatments and five replications. For this test, the primary callus were cultured using medium supplemented with 2,4D and BAP. Observation variables included the time of embryonic callus formation; callus texture; percentage of embryonic callus formation; percentage of proembryo formation. The conclusion of the study was that each variety showed a different response to the added PGRs formulation, in addition, the use of 2,4-D 2 ppm + 1 ppm kinetin was able to stimulate primary callus formation from leaf explants. Gayo and Orange Burbon varieties showed the development of embryonic callus towards the proembryo phase.