In order to achieve adventitious shoot regeneration from young tissues of Racosperma mangium, several combinations of growth regulators were tested. Kinetin (KIN) and a -naphthalenacetic acid (NAA), thidiazuron (TDZ) and NAA or indole-3-butyric acid (IBA), 4-CPPU and 2,4-dichlorophenoxyacetic acid (2,4-D) were added to basic medium composed of MS salts, MS vitamins and 3% sucrose. Sections of hypocotyls and cotyledons of young seedlings were cultivated on these media. Calli developed on different media and, after two to three months, some of them regenerated organized structures. Histological studies revealed hypertrophy and hyperplasy of medular and cortical parenchyma cells of hypocotyl and cotyledon parenchyma. Formation of meristematic cells and traqueary elements from parenchyma was observed during in vitro culture. In some cases, nodules of traqueary elements were formed. The highest differentiation into meristematic cells was found in cotyledon tissues cultured on 4-CPPU (8.07 µM) and 2,4-D (1.13 µM).
4-CPPU; Leguminosae; TDZ; Tissue culture
