Plant growth regulators optimization for in vitro cultivation of the orchid Guarianthe skinneri (Bateman) Dressier & W.E.Higgins

Resumo

An in vitro culture procedure was developed to induce shoots and roots of Guarianthe skinneri (Orchidaceae) plantlets regenerated from seed-derived protocorms on a Murashige and Skoog (MS) medium supplemented with 6-benzyladenine (BA), indole-3-acetic acid (IAA), ?-naftalenacetic acid (NAA) and gibberellic acid (GA3). A maximum of 10.6 shoots was obtained with 16.1 ?M NAA, 17.1 ?M IAA, 6.3 x 10-9 ?M GA3 and 0.0023 ?M BA. A maximum of 4.0 roots on each shoot with 5.4 ?M NAA, 17.1 ?M IAA, 0.001 ?M AG3 and 4.6 x 10-9 ?M BA. Maximum shoot and root length was obtained with a minimum of GA3, but a maximum IAA. GA3 was the main factor controlling shoot and root induction and elongation.