BACTERIAL CONTAMINATION CONTROL IN BANANA EXPLANTS (Musa AAA cv. CAIPIRA)

Abstract

Bacterial contamination control methods were evaluated in in vitro multiplication of banana plants (Musa AAA cv. Caipira), using NaOCl, rifampicin antibiotic and their combinations. It was not observed excessive explant oxidation after the immersion in NaOCl or rifampicin. The best treatment for recently isolated explants was the immersion in 1% (v/v) NaOCl for ten minutes, followed by immersion in 300 mg L-1 rifampicin for twenty minutes. After contamination, the best treatment was the immersion in 1% NaOCl for ten minutes, followed by immersion in 300 mg L-1 rifampicin for twenty four hours in the dark. The highest contamination control efficiency was obtained with prior immersion of explants in 5% (v/v) NaOCl for twenty minutes, followed by immersion in 300 mg L-1 rifampicin for twenty minutes, and growing in culture medium containing 100 mg L-1 rifampicin. This treatment, however, reduced significantly the explant multiplication. No abnormalities were observed in the explants or plantlets growing in rifampicin-containing culture medium.

KEY-WORDS: Tissue culture; banana plant; bacteria; NaOCl; rifampicin.