Influência da qualidade de luz no cultivo in vitro de Eucalyptus grandis Hill ex Maiden × Eucalyptus urophylla S.T. Blake

Abstract

The expansion of plantations and the search for better adaptation in the production of clonal plants have increased the use of species and hybrid combinations. Thus, the hybridization of Eucalyptus grandis with Eucalyptus urophylla has provided excellent results in wood quality, development, edaphoclimatic adaptation and greater ease of vegetative propagation. However, alternatives for the rejuvenation/reinvigoration in tissues of hybrid clones of the Eucalyptus genus, aiming at greater multiplication and improvement of adventitious rooting, the micropropagation technique has been recommended, which allows considerable advances in the production of clonal plants. In view of the above, the present study aimed to evaluate the effect of photomyxotrophism and the use of temporary immersion bioreactors (TIB) in the process of photomorphogenesis and development of E. grandis × E. urophylla, being divided into four articles. The aim of the first article was to evaluate the effect of light quality in the establishment, multiplication, elongation and rooting phases in vitro. Therefore, it was observed that the use of red/blue LED and fluorescent lamp light quality provided the best results for all phases of micropropagation. For the second article, the aim of the study was to analyze the influence of light intensity on in vitro introduction and multiplication. As for the results, the use of light quality and intensity fluorescent lamp 40 μmol m-2 s-1 and red/blue LEDs 80 μmol m-2 s-1 are the most suitable for use on in vitro introduction and multiplication. In the third article, the study aimed to evaluate the effect of photomyxotrophism (light intensity and sealing forms) on elongation and rooting in vitro. Based on the results obtained, the treatments fluorescent lamp 40 μmol m-2 s-1 and the use of a porous membrane (1/M) are the most suitable for use in in vitro elongation and rooting. Regarding the fourth article, it aimed to evaluate the effect of spectral quality in the in vitro multiplication phase in a temporary immersion bioreactor. It was possible to conclude that the yellow and blue spectral quality provided the best results for the in vitro multiplication phase.