In vitro propagation of Cyrtopodium saintlegerianum rchb. f. (orchidaceae), a native orchid of the Brazilian savannah

Propagação in vitro de Cyrtopodium saintlegerianum rchb. f. (orchidaceae), uma orquídea nativa do cerrado brasileiro

In order to enable production of large quantities of plantlets for reintroduction programs, as well as economic exploration, Cyrtopodium saintlegerianum seeds were sown on Knudson culture medium. After seed germination, the protocorms were inoculated on Knudson culture medium supplemented with 6-benzyladenine (BA) and α-naphthaleneacetic acid (NAA). The obtained shoots were individually inoculated in Knudson supplemented with gibberellic acid (GA₃) in order to promote elongation. Seedlings were evaluated and then transplanted into trays containing commercial substrate Plantmax^(r)-HT, or crushed Acuri leaf sheath. Auxin/cytokinin ratio influenced in vitro propagation of C. saintlegerianum, resulting in increased shoot number when 2.0 mg L^-1 BA was added to the culture medium in the absence or presence of 0.5 mg L^-1 NAA. This species proved to be promising for massal in vitro multiplication. Despite having incremented in vitro shoots elongation, the use of GA₃ is unnecessary since it contributed negatively in the acclimatization of plants.

Orchidaceae; micropropagation; plant growth regulators; acclimatization