MUTIS, Journal of the Faculty of Sciences and Engineering, Jorge Tadeo Lozano University, is licensed under the Creatve Commons 4.0: Atributon - Noncommercial - No Derivatve Works 6 Establecimiento in vitro de protocormos de Prosthechea sp. bajo diferentes concentraciones de ácido nafalenacétco Arlete Ivone Gil Clavijo 1* , Diego Fernando Contreras Pico 2 , Luis Carlos Gutérrez Rojas 2 1 Universidad de Cundinamarca, Facultad de Ciencias Agropecuarias, Programa de Ingeniería Agronómica, Grupo de investigación PROSAFIS, Diagonal 18 N° 20-29, Fusagasugá, Colombia. *Autor para correspondencia: arlettegil@hotmail.com 2 Universidad de Cundinamarca, Facultad de Ciencias Agropecuarias, Programa de Ingeniería Agronómica, semillero de investigación SEMINAC, Diagonal 18 N° 20-29, Fusagasugá, Colombia. In vitro establishment of Prosthechea sp. protocorms under diferent concentratons of naphthalene acetc acid. RESEARCH ARTICLES Editor: Hernández Fernández, J. Citation: Gil, A., Contreras, D & Gutiérrez, L. (2016). Establecimiento in vitro de protocormos de Prosthechea sp. bajo diferentes concentra- ciones de ácido naftalenacético. Revista Mutis 6(1), 6-15, doi: http://dx.doi. org/10.21789/22561498.1108 Received: January 29, 2016; Accepted: April 11, 2016; Published on line: May 31, 2016. Copyright: ©2016 Gil, A., Contreras, D & Gutiérrez, L. This is an open-access article, which permits unrestricted use, distributions and reproduction in any me¬dium, provided the original author and source are credited. Competing Interests: The authors have no confict of interest. ABSTRACT Prosthechea sp. is a wild orchid craved by the color and shape of its fowers that is disappearing from the environment because of deforestaton and its removal from the populaton present in the rural area of the Fusagasugá municipality (Cundinamarca, Colombia). The efect of four concentratons (0; 1,5; 3 and 4 mg/l - 1 ) of Naphthalene acetc acid (NAA) was proved on the development of Prosthechea sp. protocorms. The bioassay was conducted under in vitro conditons for 42 weeks, in an asymbiotc relatonship. The rootng media supplemented with 1,5 mg/l -1 NAA had no efect on root formaton, however the protocorms proliferaton was presented by adventtous gemmaton in 80%. The concentratons of 3 and 4 mg/l -1 NAA had a development of seedlings in 70% and 65% respectvely, introducing abundant thick roots and root hairs. It was observed the triple response in the treatments with the highest NAA concentratons because of the ethylene synthesis, afectng the root geotropism. This research will serve as basis for future multplicaton and conservaton projects, contributng to the preservaton of the wild fora and genetc resources with great ecological and economic potental such as orchids. Key words: micropropagaton, asexual reproducton, auxins. RESUMEN Prosthechea sp. es una orquídea silvestre apetecida por el color y forma de sus fores, que está desapareciendo paulatnamente en el municipio de Fusagasugá (Cundinamarca, Colombia) a causa de la deforestación y extracción por parte de la población presente en la zona rural. Se probó el efecto de cuatro concentraciones (0; 1,5; 3 y 4 mg/l-1) de ácido nafalenacétco (ANA) sobre el desarrollo de protocormos de Prosthechea sp. El cultvo se llevó a Vol. 6 (1) pp. 6-15, enero-junio 2016