Asymbiotic germination of Odontoglossum gloriosum Rchb.F. (Orchidaceae) under in vitro conditions

An efficient seed germination system was developed for an endemic and endangered orchid of the prairies of Bogota, Colombia. The effects of three culture media [Murashige and Skoog (MS) salts (1962); Knudson C (KC) salts (1946); and Hydro-Coljap (R) salts], activated charcoal [0 and 0.5% (w/v)], alpha-naphthaleneacetic acid (NAA; 0.0, 2.68 and 5.37 mu M), and four light regimes (white light, darkness, red light, and far-red light) on asymbiotic germination of Odontoglossum gloriosum, were studied. The best germination percentage and germination time was obtained on agar-solidified medium supplemented with Hydro-Coljap (R) salts and 2.68 mu M NAA under red light with a 16-h photoperiod. The addition of activated charcoal did not stimulate either germination or the development of O. gloriosum seedlings. This study describes a single medium-based protocol able to achieve more than 330 000 seedlings within 40 wk, starting from a single capsule. This protocol is sufficient for both large-scale propagation and in vitro conservation of this threatened orchid.