Enxertia in vitro de clones de Eucalyptus urophylla x E. grandis

• Autor(a) principal: Bandeira, Fabiana Schmidt
• Data de Publicação: 2004
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3037
• topic: Eucalyptus urophylla; Eucalyptus grandis; Propagação; Enxertia; Eucalyptus urophylla; Eucalyptus grandis; Propagation; Grafting; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::SILVICULTURA

The objective of this work was to evaluate the in vitro grafting efficiency on the propagation of two Eucalyptus urophylla X E. grandis clones. Juvenile stocks obtained from Eucalyptus grandis and Eucalyptus urophylla germinated in aseptic conditions were used. The evaluations to verify the success percentage and graftings height growth during the in vitro stage (at 35 and 50 days), and survival and height growth of the grafted plants in vitro after the acclimation stage in the ex vitro conditions (at 25, 32, 50 and 70 days) in relation to various periods of permanence of the plants in the dark after grafting (0, 7, 14 and 21 days) were done. The histologic analysis made on the union region of the graftings was made at 7, 14, 21, 28 and 50 days after the in vitro grafting. It was observed that the cicatrization processes of the callus formed on the damaged region and the vascular reconnection on the grafted plants occurred at 14 days after grafting. In relation to height growth during the in vitro stage it was observed a similar behavior between the clones and the stock used. As to the success percentage of the in vitro graftings, for the clone 1, the best results (87%) were obtained when the plants were maintained in the dark for until 14 days after grafting, and for clone 2, the best response (93%) was observed for the dark permanence time of 7 days. In the greatest period of darkness (21 days), the clone 2 grafted on Eucalyptus urophylla saplings showed a greater susceptibility, with vigor loss of the plants and most of the graftings oxidized wich resulted in a reduced number of plants surviving the stage of transference to ex vitro conditions. In the stage of ex vitro acclimation and hardening, there was no significant difference between the clones and dark treatments in relation to the initied in vitro condition. The results obtained allow to conclude that the in vitro grafting methodology adopted showed to be efficient and has potential of use in the clonal propagation and in studies related to clonal rejuvenation of Eucalyptus spp., which are represented by the high survival rate of the grafted plants, which was up to 87% at the end of the ex vitro acclimation stage.