Chitosan, polymer β-1,4 - linked D-glucosamine, has been used alone or combined with growth regulators on plant regeneration protocols in vitro such as orchids and oil palm. However, the functionality of this biopolymer in vitro regeneration of cotton species is still unknown. In order to test the efficacy of the chitosan in direct organogenesis in colored cotton cultivar BRS Rubi, experiment was conducted using explants derived from cotyledonary nodes excised from stock plants in vitro which were subcultured on MS medium supplemented with 15.0 mg L-1 of the chitosan isolated or associated with 3.0 mg L-1 6-benzylaminopurine and different concentrations (0, 0.1, 0.5 and 1.0 mg L-1) butyric acid, naphthalene acetic acid and kinetin. The cultures were kept in a growth chamber at 25 ± 2 ºC with a photoperiod of 16 h light and light intensity of 40 µmol m-2 s-1 for 50 days. The analysed variables were number of shoots/explant and size of the largest shoot. The best results were obtained in the treatments supplemented only with 6-benzylaminopurine and chitosan. However, isolated chitosan did not induce multiple shoots in the studied cultivar.
cv. BRS ruby; in vitro culture; multiple shoots; D-glucosamine; growth regulators
