Brassinosteroid in combination with cytokinin increases the efficiency to induce somatic embryogenesis

Brassinosteroid increases the cytokinin efficiency to induce direct somatic embryogenesis in leaf explants of Coffea arabica L. (Rubiaceae)

     The combination of different plant growth regulators can result in beneficial effects in the induction of in vitro morphogenetic pathways. Explants cultured on MS medium supplemented with 1.0 µM 24-epiBR (brassinosteroid) in association with 2-iP (cytokinin) produced 6.8 times more somatic embryos than the explants cultured with only 2-iP. Histological analyses also provided evidence that the supplementation of brassinosteroids in the culture medium could have influenced somatic embryogenesis differentiation.  Somatic embryos obtained in the presence of brassinosteroid and cytokinin were better structured morpho-histologically as compared to those obtained in the medium with just cytokinin. This study opens new perspectives for the use of brassinosteroids in the somatic embryogenesis of C. arabica, so as to optimize the in vitro regeneration systems used in genetic improvement programs in C. arabica productive systems.