Induction of somatic embryos in robusta and conilon varieties of coffea canephora

Clonal propagation of Coffea canephora varieties is feasible through somatic embryogenesis. The aim of this study was to evaluate the induction of somatic embryos from leaves of C. canephora, Robusta and Conilon varieties, in relation to different concentrations of three growth regulators. The explants were inoculated in a MS culture medium with 2iP (isopentanyladenine), IBA (indolebutyric acid) and BA (6-benzylaminopurine), in factorial combinations, at concentrations of 1.0; 2.0; 3.0; 4.0 and 5.0 mg L-1. At 45 days of culture, the percentage of callus induction was evaluated and, at 120 days, the average number of cotyledonary embryos per explant. The most efficient combinations of growth regulators to induce callogenesis in the explants were: 5.0 mg L-1 of IBA + 1.0 mg L-1 of 2iP and 3.0 mg L-1 of IBA + 3. 0 mg L-1 of BA – for the Robusta variety; and 5.0 mg L-1 of IBA + 1.0 mg L-1 of 2iP and 5.0 mg L-1 of IBA + 5.0 mg L-1 of BA – for the Conilon variety. As for the average number of embryos per explant, the most efficient combinations of growth regulators were: 5.0 mg L-1 of IBA + 1.0 mg L-1 of 2iP and 2.0 mg L-1 of IBA + 3 .0 mg L-1 of BA – for the Robusta cultivar; and 4.0 mg L-1 of IBA + 1.0 mg L-1 of 2iP and 5.0 mg L-1 of IBA + 5.0 mg L-1 of BA – for the Conilon variety.