Callogenesis was achieved using growth regulators at different concentrations to obtain the
best characteristics regarding the calluses texture aspect with the main objective to produce
friable calluses from stem explants of Eucalyptus grandis. Stem segments of approximately 1Â cm
were excised from 30-day seedlings. The treatments were prepared based on the MS medium
added with TDZ alone or combined with AIA; 2,4-D; ANA. Each treatment consisted of five
repetitions with five explants per plate. After 210 days of in vitro culture, the calluses were
evaluated visually and by manipulation for texture. The explants that did not produce calluses
were those exposed to treatments with 2,4-D 50.0 µM; TDZ 3.0 µM and in absence of a growth
regulator (control).The best protocols for maintenance of friable calluses of stem explants of
Eucalyptus grandis under the conditions performed in this work were those using only TDZ.
