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Clonal propagation optimization of Eucalyptus globulus Labill

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Germana Marcelino Cordeiro
Total Authors: 1
Document type: Master's Dissertation
Press: Piracicaba.
Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
Defense date:
Examining board members:
Marcilio de Almeida; Fernando Angelo Piotto; Paulo Henrique Müller da Silva
Advisor: Marcilio de Almeida

Few Eucalyptus species present adaptation for cultivation in regions with low temperatures and frequent frosts, limiting their cultivation in some regions of Brazil. E. globulus genotypes may to represent future options for forest plantations, in view of its optimal silvicultural performance in these conditions. However, information about obtaining clonal seedlings are scarce, and considering the species recommended for planting in subtropical conditions, this lack of information is even greater, mainly when considering the endogenous and exogenous factors for the rooting. This species is distinguished by great interest in forestry, particularly in relation to characteristics of its wood to obtain cellulose, however, it is considered recalcitrant to rooting, especially when it involves adult material, making it difficult to utilize the cloning benefits. Therefore, this study aimed to evaluate the micropropagation technique of E. globulus clones, in order to revert to juvenility, increasing the rate of rooting and consequently the clonal production. For this, the clones (USP 01, USP 24 and USP 33) were studied and showed satisfactory in vitro culture establishment, where it was evaluated: (a) the in vitro multiplication, testing three culture media (WPM, JADS and MS) supplemented with concentrations plant growth regulator BAP (0; 0,50 and 1,0 mg L-1) combined with NAA (0; 0,05 and 0,10 mg L-1); (b) the in vitro elongation, testing the WPM medium culture supplemented with BAP concentrations (0; 0,05 and 0,10 mg L-1) combined with NAA (0; 0,1; 0,2 and 0,3 mg L-1); and (c) in vitro rooting, where elongated shoots in vitro of the clones were collected and transferred to WPM, supplemented with 0 and 0,05 mg L-1 BAP combined with 0; 0,1, 0,5 and 1,0 mg L-1 IBA. The results showed different behaviors of clones as in vitro multiplication and elongation. Rates of clones in vitro multiplication varied over the 10 subcultures, with the stabilization from the sixth subculture for all clones, the largest rate multiplication (average number of 13 buds) in the concentration of 0,7 mg L-1 BAP and 0,05 mg L-1 NAA in WPM. The culture media WPM evaluated in vitro elongation, contributed positively to the shoots elongation, with 0,3 mg L-1 NAA and 0,1 mg L-1 BAP. Therefore, with the micropropagation protocol using axillary buds proliferation of these clones showed be well developed , however, in relation to rooting, only one root was emitted at 0,5 mg L-1 IBA in clone 01. In general, it is possible concluded that despite viable, the micropropagation did not promote significant rejuvenation of E. globulus clones, due to the not expressive rooting for the microcutting evaluated. (AU)