Germinação assimbiótica e desenvolvimento de Dendrobium nobile Lindl. sob efeito de reguladores vegetais no tratamento pré-germinativo

Asymbiotic germination and development of Dendrobium nobile Lindl. under the effect of plant growth regulators in pre-germinative treatment. The present study aimed to investigate the influence of plant growth regulators BAP and GA 3 as pre-germinative treatment in the process of germination and initial development of seedlings of Dendrobium nobile, a species important for its pharmacological properties like antioxidant, vasodilator and even anticancer, besides its ornamental value. Pre-germinative treatments consisted of BAP and GA 3 , separately, at the concentrations of 0.0; 1.0; 2.0 and 5.0 mg L -1 . At six months after in vitro sowing and maintenance in a germination and growth chamber with controlled temperature and photoperiod (12 hours and 23oC ± 2), the following parameters were evaluated: number of germinated seeds, percentage of germination, fresh mass and height of seedlings, number and diameter of pseudo-bulbs, number of leaves, number of roots, and length of the largest root. The experimental design was completely randomized. All variables underwent analysis of variance and regression analysis when significant. D. nobile seeds presented better germination in the absence of plant growth regulators and the treatments with BAP or GA 3 in seed imbibition little benefited D. nobile in vitro development.