Resumo

I. URREA, Aura; GOMEZ, Sonia  e  NARANJO, Esther J.. In vitro culture response of Zamia incognita, an alternative for preservation. Rev. colomb. biotecnol [online]. 2012, vol.14, n.2, pp.121-133. ISSN 0123-3475.

Zamiaceas are relict plants considered living fossils. In Colombia, 65% of this family is under some threat category due to their habitat destruction and their intense collection. Given that the advantages of in vitro propagation is ex situ conservation of germoplasm, this study aimed to evaluate the regeneration potential of Z incognita plants from leaf explants and zygotic embryos. The effect of different combinations of auxin (2.4-D and NAA) and cytokinins (KIN, BAP and TDZ) was evaluated on the formation of callus and shoot regeneration (direct or indirect), using MS (MB1) basal medium and B5 (MB2) basal modified medium. The callus formation was presented over a wide concentration range of 2.4-D with KIN and 2.4-D with BAP, regardless of the basal medium, but not in explants treated with ANA more TDZ or KIN. For leaf explants there was no response to the formation of somatic embryos or shoots with hormonal combinations and concentrations evaluated; however, MB2 calluses induced with 2.4-D (0.22 mg / l) and BAP (0. 1 , 2. 3 mg / l) were different, their nodular aspect, cream color and pro-embryogenic appearance coincided with a lot of potential meristematic cells for the regeneration process. From immature zygotic embryos, somatic embryo formation in the MB2 medium was achieved without growth regulators or containing 2.4-D alone (0.22 mg /l) or 2.4-D in combination with BAP (1 mg/l) without achieving the conversion process to seedlings.

Palavras-chave : microprogation; young leaves; plant growth regulators; zygotic embryos; basal medium.

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