Induction of indirect somatic embryogenesis in sucuuba leaf explants and nodal segments

Abstract

Somatic embryogenesis can be an alternative for seedling production of native species with socioeconomic importance, such as sucuuba. In this sense, this study aimed to induce somatic embryogenesis in callus originated from nodal and leaf segments under different culture conditions. Initially, callus formation on explants was induced in Murashige and Skoog (MS) culture medium with dichlorophenoxyacetic acid (2,4-D) and Tidiazuron (TDZ) (18.08+9.8 μM and 4.52+6.81 μM). The friable calli obtained were transferred to B5-Gamborg (B5) medium supplemented with activated charcoal and abscisic acid (ABA) for maturation of embryogenic structures. The potential for conversion of embryos into seedlings was evaluated on B5 medium supplemented with indolbutyric acid (IBA) +BAP (6-benzylaminopurine). The design used in the maturation and germination phases was entirely randomized, with 2x2x4 and 2x2x2 factorial arrangement, respectively: 2 explants, 2 lighting conditions (white light and dark), 4 concentrations of ABA (0, 10, 20 and 30 μM) or 2 concentrations of AIB + BAP (1+2.5 μM and 1+5 μM). Data were subjected to analysis of variance (ANOVA) and Tukey’s test at p<0.05. There was a two-way interaction between explant type and luminosity, and absence of significant differences for ABA. The callus induction protocol was efficient, while the maturation and germination protocols did not make it possible to obtain seedlings. Thus, further studies should be conducted to minimize phenolic contamination and oxidation, and consequently, intensify the expression of somatic embryogenesis.