Soil salinity is an important factor of stress that occurs in many semi-arid and arid regions of Brazil where the bananeira is cultivated. The effect of different sodium chloride (NaCl) concentrations, in vitro, on the growth and shoot multiplication derived from explants of "Grand Naine" variety was studied. The shoot-tips of the bananeira were inoculated in MS media in the absence: T0=0 (control) and in the presence of three NaCl treatments: T1=50mM, T2=75mM e T3=100mM and sub cultured five times in the respective treatments. The subcultures were carried out every 30 days and the number of shoots multiplicated on each inoculated shoot, length and total number leaves of inoculated shoot and production of fresh weight were observed at 0; 30; 60; 90; 120 e 150 days after salt exposition. The results showed that the presence of NaCl in the media affects the shoot's production in vitro. The increase of NaCl concentration in the media is proportional to the decrease in the number of shoots produced. The multiplication of bananeira's shoot reduced about 80% in the treatment T1, while the treatments T2 and T3 achieved 90% of reduction. On the other hand the two saline treatments 75 and 100 mM interfered at the same form in the growth of shoots, production of fresh weight, length and total number of leaves. Under experimental conditions the best dose among the different sodium chloride was 50 mM because this dose showed intermediary effects on the characters evaluated.
Musa sp; salt stress; in vitro multiplication
