In vitro multiplication of Eucalyptus hybrid via temporary immersion bioreactor: culture media and cytokinin effects

Abstract

This study aimed to assess the influence of culture medium and cytokinin type on in vitro multiplication of an Eucalyptus grandis x E. urophylla hybrid clone via temporary immersion bioreactor (TIB^®). JADS, modified MS at a (NO₃ˉ):(NH ⁺) ratio, and WPM were used as liquid media; and 6-benzilaminopurine (BAP), kinetin (KIN), and thidiazuron (TDZ) were the cytokinins used in the study. According to the results, explants under the influence of modified MS presented better results for all traits analyzed in this study. BAP was the most suitable plant growth regulator for axillary bud shoot proliferation. By the leaf histological analysis, most of the shoots grown in the presence of BAP either exhibited normal morphology or only a few hyperhydricity symptoms. All these results were obtained at 19 days after in vitro cultivation, a shorter period when compared with other works in the literature, showing the protocol efficiency in the multiplication of this hybrid clone using TIB®.

Key words:
6-benzilaminopurine; hyperhydricity; plant biotechnology; in vitro propagation