Iraídes Fernandes Carneiro

CRESCIMENTO E OXIDAÇÃO DE EXPLANTES DE BANANEIRA PRATA (Musa AAB) IN VITRO: IV. CONCENTRAÇÕES DE SAIS, ÁCIDOS ASCÓRBICOS E FREQÜÊNCIA DE SUBCULTIVOS

MS medium salt and ascorbic acid concentrations, and subculture periodicity, were evaluated with the aim of controlling explant phenolic oxidation of banana plants, cv. Prata (Musa AAB). All possible combination of salt concentrations of the MS medium (100%, 50% and 33,33%), subcultures periods (each 7 days, each 14 days, and each 28 days after inoculation), and ascorbic acid (0 and 25 mg L-1), were studied. Explant fresh weight, height and oxidation levels were evaluated 28 days after inoculation. Results showed that explant initial growth, determined in fresh weight, was affected by the reduction of MS medium salt concentration when subculture frequency was 28 days. Results was showed that is not necessary addition of ascorbic acid by reduction browning when the salt concentration of MS medium is reduced and the subculture frequency is enlarge, therefore the explant fresh weight was increased.

CRESCIMENTO E OXIDAÇÃO DE EXPLANTES DE BANANEIRA-PRATA (Musa AAB) IN VITRO: I. CONCENTRAÇÕES DE SAIS DE FERRO, COBRE E ZINCO

This research work was carried to verify the effects of salt concentrations with iron, copper and zinc of the MS (MURASHIGE & SKOOG, 1962) medium on explants oxidation control for banana plants, cv. Prata (Musa AAB). Three salt concentrations (100, 50, 0 mM) of FeEDTA and two concentrations (100, 0 mM) of (CuSO4). 5H2O and two concentration (30 e 0 mM) of (ZnSO4). 7H2O were utilized. Completely randomized in a 3x2x2 factorial scheme with fifteen repetitions were utilized. Shoot tip apices were inoculated in MS medium. Explants fresh matter weight, height and oxidation grade were evaluated 28 days after inoculation. It was observed that iron, copper and zinc are essential to explants growth. Iron concentration reduction caused decrease in oxidation grade, the reduction or elimination of iron, copper and zinc in MS medium, isolated or in combination forms was not sufficient to eliminate the oxidation grade.