Plant growth regulators optimization for in vitro cultivation of the orchid Guarianthe skinneri (Bateman) Dressier & W.E.Higgins. 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) médium supplemented with 6-benzyladenine (BA), indole-3-acetic acid (IAA), a-naftalenacetic acid (NAA) and gibberellic acid (GA3). A máximum of 10.6 shoots was obtained with 16.1 μM NAA, 17.1 μM IAA, 6.3 x 10-9 μM GA3 and 0.0023 μM BA. A máximum of 4.0 roots on each shoot with 5.4 μM NAA, 17.1 μM IAA, 0.001 μM AG3 and 4.6 x 10-9 μM BA. Máximum shoot and root length was obtained with a minimum of GA3, but a máximum IAA. GA3, was the main factor controlling shoot and root induction and elongation.. https://bibliotecadigital.infor.cl/handle/20.500.12220/29586