It was studied the effect of auxin concentration and liquid medium on the development of cupuassu calli. Cupuassu embryonic axes segments and cotyledons, from kinds Mamorana and Redondo, were cultivated in four different culture media : 1) MS medium (50%) supplemented with 2,4-D (1; 2; 4; 8 mg/L); 2) N6 salts (SIGMA) (4 g/L) supplemented with 2,4-D (0; 2; 4 mg/L) and NAA (0; 3; 5 mg/L); 3) similar to the previous medium supplemented only with NAA (3 mg/L) and, 4) MS medium, supplemented with NAA (1 mM). Calli with white and bright aspect were observed in embryonic axes and cotyledons, cultivated in the smallest concentrations of medium 1 (1 and 2 mg/L), while in the largest concentrations (4 and 8 mg/L) opaque white calli and calli mass were formed in embryonic axes and in cotyledons segments, these structures became brownish within eight weeks. Using medium 2, a great number of roots were formed, while this same medium supplemented only with NAA (3; 5 mg/L) originated a calli mass. . The presence of NAA and 2,4-D, 3 and 2 mg/L respectively, promoted the formation of white calli and roots. The transfer of the explants to liquid medium, without growth regulator, promoted an increase of explants size and browning of them. The cultivation of those explants in medium 3 resulted in the formation of yellow calli, with friable aspect, that kept the same aspect in medium 4.
tissue culture; calli; auxin; Theobroma grandiflorum
