Protocolo de germinação em meios assimbióticos para Dendrobium nobile Lindl. E Dendrobium phalaenopsis Fitzg.

Abstract

The Dendrobium genus of orchids are one of the most produced and marketed, both in Brazil and abroad. To meet market demand, one of the techniques used in vitro culture is asymbiotic seed germination an efficient method for the rapid production of orchid seedlings resulting in higher germination rates compared to the germinating under natural conditions. However, the protocols for in vitro germination vary according to the species to be propagated, requiring suitability for each. This work was developed with the aim to determine a protocol for in vitro germination of Dendrobium nobile Lindl. and one to Dendrobium phalaenopsis Fitzg. Three experiments were conducted at the Laboratoy of in vitro culture and Jardinocultura area of the Faculdade de Ciências Agrárias (FCA) - Universidade Federal da Grande Dourados (UFGD), in which were evaluated the germination in four different culture media using disinfestation methods seeds, light conditions, agar concentrations and activated carbon. In general, germination at 45 days after sowing, was higher when it was used five minutes of disinfestation of the seeds in sodium hypochlorite solution, followed by practice of triple rinsing to asymbiotic culture media MS e MS ½. When lighting conditions were studied it was observed that D. nobile cultivated on MS medium under white fluorescent light + red fluorescent light was the highest percentage of germination and D. phalaenopsis using the same culture medium the fluorescent light white was the one that provided the highest percentage of germination. The seeds of both species germinated on all combinations of agar and charcoal studied. To obtain more developed plantlets recommended the use of media MS e MS ½ jellified with 4.0 to 8.0 g L-1 agar and free of activated carbon. Based on the results obtained, it was established one germination protocol for D. nobile and one for D. phalaenopsis.