Micropropagação, microestaquia e miniestaquia de clones híbridos de Eucalyptus globulus

• Autor(a) principal: Oliveira, Leandro Silva de
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3055
• topic: Propagação in vitro; Propagação vegetativa; Estaquia; Enraizamento de estaca; Silvicultura clonal; In vitro propagation; Vegetative propagation; Cutting; Rooting of cutting; Clonal forestry; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::SILVICULTURA

This study aimed to evaluate the propagation of Eucalyptus urophylla x E. globulus and Eucalyptus grandis x E. globulus clones, especially effects of micropropagation, micro-cutting technique and mini-cutting technique. The following features were analyzed: (a) in vitro multiplication and elongation; (b) the effect of IBA (indole-3-butyric acid) at 0 and 2000 mg L- 1; and position of the cuttings (apical and intermediate stem) on survival, rooting and plantlet vigor. The micro-clonal hedge consisted of micro-stumps rejuvenated via micropropagation through successive subcultures, whereas the mini-clonal hedge comprised ministumps obtained by rooting of mini-cuttings. The rooting of mini-cuttings and microcuttings was performed using an initial period of 30 days under greenhouse, acclimatization in the shade house for 10 days followed by transfer to sunshine condition, where the final evaluation was carried out at 60 days. The results for the micropropagation of clones revealed different behavior on the multiplication and elongation in vitro. The rates of clonal multiplication varied over the twenty-five subcultures without stabilization in the course of time. Both culture medium (MS and JADS) evaluated for in vitro elongation contributed positively to shoot elongation, as well as indole-3- butyric acid (IBA), applied in concentration above 0.25 mg L-1. Therefore, the protocol developed was efficient for micropropagation by axillary bud proliferation. Survival and the percentage of mini-cuttings and micro-cuttings with roots observed at the bottom of the container, in the exit of the greenhouse and shade house there was not show different responses for these characteristics. Regarding rooting, in general, there was superiority of apical stems cuttings in relation to the intermediate stems. The application of the IBA in the mini-cuttings and microcuttings had no effect on the evaluated parameters. The evaluations indicated speed rooting differentiated between the clones in the rhizogenic process. Based on results, micropropagation did not promote significant rejuvenation of the hybrid clones of Eucalyptus globulus. In conclusion, micro-cutting technique was superior to minicutting technique only for certain parameters evaluated for each clone.