Somatic embryogenesis in leaf explants of genipap genotypes

Abstract

The genipap (Genipa americana L.) is a non-endemic species native to Brazil belonging to the family Rubiaceae. It is a species that unites socioeconomic and environmental pillars. The study objective was to establish the induction of indirect somatic embryogenesis in foliar explants of genipap genotypes. Leaf explants of UMB, SAL, JSA, SC, and CER accessions cultivated in half the salt concentration of Murashige & Skoog (MS), 30 g/L sucrose, and 3g/L PhytagelTM with the following combinations of NAA × BA regulators were used: M1: 4.0/4.0 mg/L NAA and BA, M2: 4.0/6.0 mg/L NAA and BA, and M3: 6.0/4.0 mg/L NAA and BA. At 60 days of culture, they were transferred to secondary embryogenic callus multiplication medium supplemented with 2.21 mg/L of 2,4-D. At 30 and 60 days, the increment (%) and fresh mass (g) of primary callus and at 120 days the presence of embryogenic callus were evaluated. The primary medium with 4.0 mg/L of NAA and 6.0 mg/L of BA induced embryogenic primary callus in leaf explants of the genipap accessions SAL, SC, and JSA. The secondary medium was promising for the multiplication of embryogenic callus. Cytochemical analysis confirmed the presence of embryogenic cells in SAL, SC, and JSA accessions.