Enraizamento in vitro de Eucalyptus cloeziana F. Muell

• Autor(a) principal: Figueiredo, Alexssandra Jéssica Rondon de
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFMT
• Texto Completo: http://ri.ufmt.br/handle/1/2801
• topic: Rizogênese; Micropropagação; PH; Carboidratos; Carvão ativado; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL; Rhizogenesis; Micropropagation; PH; Carbohydrates; Activated charcoal

Among the Eucalyptus species used in the forest sector, E. cloeziana stands out for high quality of the wood, making it possible to use it in the timber, industrial and civil construction sectors. However, the expansion of commercial plantations has been hampered because the species is little responsive to rhizogenesis. The aim of the work was to establish an in vitro and ex vitro rooting phase methodology that will promote the formation of adventitious roots in Eucalyptus cloeziana. Explants of a micropropagation protocol through indirect organogenesis were used as source of propagules, and submitted to multiplication in WPM culture medium containing 0.50 mg.L-1 of BAP and 0.05 mg L-1 of NAA. The elongation step was performed in two culture media, the first one supplemented with 0.05 mg.L-1 of BAP, 0.1 mg.L-1 of NAA and 0.1 mg.L-1 of IBA, with half of salt concentrations of WPM medium. The second contained 0.1 mg.L-1 of NAA and 0.1 mg.L-1 of IBA, with 2.5 g.L-1 of activated charcoal. The first in vitro and ex vitro rooting experiment was performed with explants from the first elongation medium, and composed of four pH adjustments (3.8, 4.8, 5.8 and 6.8) and three concentrations of sucrose ( 0, 15 and 30 g.L-1). The second experiment had the same conditions as the previous one, but the explants used were submitted to the second elongation medium. The third one tested carbohydrate and their combinations (T1 = glucose (15 days) + sucrose (15 days) with phytoregulator (0.1 mg.L-1 of IBA and 0.2 mg.L-1 of NAA); T2 = (15 days) + sucrose (15 days) without phytoregulator, T3 = glucose + sucrose with phytoregulator, same concentration of previous treatment (30 days), T4 = glucose + sucrose without phytoregulator (30 days). The fourth tested the effect of activated charcoal (2.5 g.L-1) on the elongation and rooting. After 30 days, percentage of survival, rooting, number and total and average roots length were evaluated. The ex vitro rooting was performed in a mini-greenhouse system for 30 days and the same variables from the previous phase were analyzed. Acclimatization was initially conducted in laboratory and then finished in greenhouse, at that stage, the percentage of survival was evaluated. In the first experiment, no explants rooted in vitro, and under ex vitro conditions the best results were obtained at pH 5.8 with 30 g.L-1 of sucrose. In the second, the highest rooting rates were obtained with pH 3.8 and 30 g.L-1 and pH 5.8 with 15 g.L-1 and 30 g.L-1 sucrose. In the third, the best treatments were glucose (15 days) + sucrose (15 days) with phytoregulator and 15 g.L-1 glucose + 15 g.L-1 sucrose without phytoregulator (30 days). In the test of activated charcoal, the treatment containing 2.5 g.L-1 of this component in the elongation and rooting was the best. Taking into account the difficulty of E. cloeziana in the formation of adventitious roots, the results obtained are promising. In the acclimatization, satisfactory results were obtained in the experiment testing activated charcoal in the elongation and rooting phases.