Resumo

LEE ESPINOSA, Hilda E. et al. A protocol of somatic embryogenesis for the in vitro regeneration and characterization of Laelia anceps ssp. dawsonii. Rev. fitotec. mex [online]. 2010, vol.33, n.4, pp.323-332. ISSN 0187-7380.

Laelia anceps ssp. dawsonii is one of the most appreciated Mexican wild orchids, with atractive characteristics for ornamental potential according to international standards. It has become an important economic species, subjected to excessive collection and risk of extinction. To ensure its conservation, it is necessary to develop efficient propagation protocols which allow its sustainable utilization and reduce collection. Somatic embryogenesis is an efficient technology for in vitro plant multiplication. In this study we evaluated in vitro conditions for developing a somatic embryogenesis protocol for Laelia anceps ssp. dawsonii. Embryogenic calli was induced from mature seeds, in a Murashige and Skoog medium supplemented with multiple combinations of naphthalene acetic acid (NAA), 6-benzylaminopurine (BAP), kinetin (Kin) and indole 3 acetic acid (IAA). The combination NAA+BAP+IAA (2.0 mg L^-1 each) was optimal for callus induction, producing 611 embryoids in a 16 h photoperiod (33.8 µmol m^-2 s^-1) when subcultured every 45 d on the same medium. This conditions allowed for complete plantlet development. In approximately three months, plantlets achieved 4-5 cm in a V&W medium supplemented with BAP (2 mg L^-1), AIA (1 mg L^-1) and 0.2 % activated charcoal; after 30 d plantlets were acclimatized in a greenhouse with 95 % survival rate.

Palavras-chave : Laelia anceps ssp. dawsonii; in vitro culture; somatic embryogenesis; Orchidaceae.