Morfogénesis in vitro de Prosthechea vitellina (Lindley) W. E. Higgins.

Abstract

Prosthechea vitellina (Lindley) W.E. Higgins es una orquídea epífita endémica de México con valor ornamental y económico. Considerada especie amenazada debido al comercio ilegal y la creciente destrucción de su hábitat. Ante esta problemática es necesario implementar técnicas de cultivo de tejidos vegetales in vitro como opción viable para rescate, conservación y propagación masiva. Los objetivos fueron determinar las mejores condiciones para la germinación in vitro, regenerar plántulas por organogénesis directa y aclimatarlas. Se sembraron semillas provenientes de capsula cerrada en medio MS a la mitad de concentración de sales (50%) adicionado con 6-benciladenina (BA, 2.22, 4.44 µM) y ácido naftalenacético (ANA, 0.44 µM). La organogénesis se indujo a partir de plántulas germinadas in vitro, sembradas en medio MS (100% y 50%) con BA (5.0-10.0 µM) ANA y AIA (1.0-2.0 µM). En alargamiento grupos de brotes se colocaron en medio MS (100% y 50%) con y sin carbón activado (0.5 g L-1). En multiplicación, brotes (1.8 cm) se cultivaron en medio MS con BA (4.5- 13.6 µM), ANA y AIA (0.0- 1.14 µM). En enraizamiento se cultivaron brotes en medio MS (50%) adicionado con AIB, AIA Y ANA (0.0-10.0 µM). En aclimatación se evaluaron plantas enraizadas in vitro de 5 y 7 cm en turba+perlita (1:1) y corteza de pino. La germinación fue de 91.8%. En organogénesis la mayor cantidad de brotes (2.03) se indujeron con 10.0 µM de BA +1.0 µM de ANA y en multiplicación se obtuvieron 2.5 brotes con 4.5 µM de BA y 1.14 µM de AIA a las ocho semanas. El alargamiento mayor de brotes (2.16 cm) se logró con MS (50%) + 0.5 g L-1 de carbón activado. El mayor número de raíces se produjo con 10 µM de AIB con 5.27 raíces por planta. La supervivencia fue de 100% con plantas de 7 cm en corteza de pino. _______________ In vitro MORPHOGENESIS OF Prosthechea vitellina (Lindley) W. E. Higgins. ABSTRACT: Prosthechea vitellina (Lindley) W.E. Higgins is an epiphytic orchid endemic to Mexico with ornamental and economic value. Considered a threatened species due to illegal trade and the increasing destruction of its habitat. Given this problem, it is necessary to implement in vitro plant tissue culture techniques as a viable option for rescue, conservation and mass propagation. The objectives were to determine the best conditions for germination in vitro, to regenerate seedlings by direct organogenesis and to acclimatize them. Seeds from closed capsule were sown in MS medium at half salt concentration (50%) added with 6-benzyladenine (BA, 2.22, 4.44 µM) and naphthaleneacetic acid (ANA, 0.44 µM). Organogenesis was induced from in vitro germinated seedlings, placed in MS medium (100% and 50%) with BA (5.0-10.0 µM), ANA and AIA (1.0-2.0 µM). In elongation, groups of shoots were placed in MS medium (100% and 50%) with and without activated charcoal (0.5 g L-1). In multiplication, shoots (1.8 cm) were placed in MS medium with BA (4.5- 13.6 µM), ANA and AIA (0.0-1.14 µM) were added. During rooting, shoots were grown in MS medium (50%) added with AIB, AIA and ANA (0.0-10.0 µM). In acclimatization, in vitro rooted plants of 5 and 7 cm in peat + perlite (1: 1) and pine bark were evaluated. Germination was 91.8%. In organogenesis, the highest number of shoots (2.03) were induced with 10.0 µM of BA +1.0 µM of ANA and in multiplication 2.5 shoots were obtained with 4.5 µM of BA and 1.14 µM of IAA at eight weeks. The greatest elongation of shoots (2.16 cm) was achieved with MS (50%) + 0.5 g L-1 of activated charcoal. The highest number of roots was produced with 10 µM IBA with 5.27 roots per plant. Survival was 100% with 7 cm plants in pine bark.