The blackberry (Rubus sp.) micropropagation is used, mainly for obtaining virus-free plants in short period of time. In the present work different concentrations of sodium chloride (NaCl) and naphthaleneacetic acid (NAA) were tested added to in vitro culture medium of blackberry cv. Brazos. The culture medium consisted of MS salts, with 30 g L-1 sucrose 6 g L-1 agar and pH adjusted to 5.8 before the sterilization at 121ºC and 1 atm for 20 minutes. The treatments consisted of NaCl (0; 25; 50; 75 and 100 mg L-1) and NAA (0; 0.01; 0.5; 1.0 and 1.5 mg L-1) concentrations, in all possible combinations. Nodal segments, originating from plants established in vitro were excised and introduced in tubes containing 15 mL of culture medium. After that, the tubes were transferred to growth room at 25 ± 2ºC, irradiance of 35 mmol m-2 s-1 and photoperiod 16 hours. A completely randomizel block design with four replicates and 12 plants per replicate was used. The experiment was evaluated after 70 days of in vitro cultivation. The in vitro development of the cv. Brazos was favored in the treatments with 50 to 75 mg L-1 NaCl and 1.0 to 1.5 mg L-1 NAA, while the best rooting results were obtained using 100 mg L-1 NaCl and 1.5 mg L-1 NAA.
Culture medium MS; micropropagation; NaCl; NAA; Rubus sp.; cv. Brazos
