Aspectos fenológicos e cultivo in vitro de Bromelia reversacantha Mez (Bromeliaceae)

• Autor(a) principal: Costa, Luiz Valério Afiune
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/001300000fbvk
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/9684
• topic: Bromélias; Cerrado; Fenologia; Propagação; Paisagismo; Bromeliads; Phenology; Propagation; Landscape gardening; CIENCIAS BIOLOGICAS::GENETICA

Bromelia reversacantha is a species of the Bromeliaceae family which occurs in areas of Cerrado Rupestre. It is characterized for being a terrestrial species, growing on sandy soils, in dry and semi-shade environment. It presents interesting ornamental characteristics for the landscape gardening, such as persistent leaves, showy and lasting inflorescence. However, this species, like so many of Cerrado, is threatened by the expansion of the agricultural activities in this bioma and by the predatory extration. The knowledge on phenologic stages and of growth factors and the development of these plants under in vitro and ex situ conditionswould allow to get in vitro culture protocols,enabling actions of preservation and management of such species. The present work had as objective to present the aspects of the growth and vegetative development and the reproductive phase of sets of plants located in the Biological Reserve Prof. Jose Ângelo Rizzo, city of Mossâmedes, Goiás state. Moreover, seeds collected in the Reserve had been germinated and served of source of explants for the attainment of in vitro propagation protocols. The results of the analyzed variable of growth had indicated that hidric deficiency and more cold temperatures do not favor the development of the plant. The vegetative propagation, bylateral shoots, was observed in almost every months. The flowering period presents a average of 11.70 days with an average of 4.84 open flowers per day. The nectar presented an average volume of 29.73 μL with average of 34.25o Brix, attracting diverse insects and hummingbirds. It did not have production of fruits in the inflorescences submitted to spontaneous self-pollination. However, tests of geitogamy and xenogamy had produced fruits indicating that the species is possibly allogamous. Seeds of B. reversacantha had presented high percentage of germination, with an average of 98.13%. In the experiments for in vitro propagation, the used culture medium was the MS, supplemented with 30 g.L-1 of sacarose and 0.1 g.L-1 of inositol and 6 g.L-1 of agar, beyond the growth-phytoregulator NAA in three treatments: T1: growth-phytoregulator free; T2: 1 mg.L-1; T3: 2 mg.L-1 (experiment1). After 315 days in culture, the treatment with 2 mg.L-1NAA promoted higher ratein vitro multiplication by the adventitious shoots induction. In the experiment 2, the treatments involved combinations of the growth-regulators BAP and NAA, in three treatments: T1: BAP 2 mg.L-1 and NAA free; T2: BAP 2 mg.L-1 and NAA 1 mg.L-1 ; T3: BAP 2 mg.L-1 and NAA 2 mg.L-1. After 260 days in culture, the combination of BAP 2 mg.L-1 with NAA 1 mg.L-1 promoted higher rate of in vitro multiplication, by indirect organogenesis. These results indicate that the in vitro production of plantlets is a viable activity and that can produce great amount of plantlets in short time.