Gustavo Alves Pereira

Desinfestação e estabelecimento in vitro de explantes de bananeira 'Grande Naine' em diferentes concentrações de hipoclorito de sódio

Brazil is one of the world largest producers of bananas, with a planted and harvested area of 504.586 ha in 2006 (IBGE, 2008). Most of the banana plantations are still cultivated using the traditional rooted young plants, but other methods of propagation such as in vitro micropropagation are constantly being developed and improved, to increase the multiplication rate in short time and to improve the quality of the seedlings production. However, contamination is a major problem of this technique. This study aimed to evaluate the efficiency of decontamination of banana explants, using different concentrations of active chlorine during the sterilization of the explants. The experimental design was randomized and consisted of five treatments and five repetitions, each one of 5 explants, at different concentrations of active chlorine, T1 (control) without active chlorine, T2 (0,5%), T3 (1,0%), T4 (1.5%) and T5 (2%). The contaminations were subjected to analysis of variance and means compared by Tukey test at 5% probability. The results showed that the highest efficiency among the treatments was the immersion of explants in sodium hypochlorite solution with 2% active chlorine, and the doses tested were not toxic to the explants, allowing normal development of them, thus concluding that concentration can be used to control contamination in banana micropropagation.

Uso da ampicilina sódica e cloranfenicol no controle de contaminantes na micropropagação de bananeira 'Thap maeo'

Use of the antibiotics sodium ampicillin and chloramphenicol to control contamination in micropropagation of ‘Thap maeo’ banana Micropropagation has been developed to enhance the multiplication rate in a short time and improve seedling quality. However, microbial contamination is a major problem in micropropagation. This study aimed to evaluate the efficiency of decontamination of banana explants during in vitro establishment with the addition of the antibiotics sodium ampicillin and chloramphenicol to the culture medium. The experiment was arranged in a completely randomized design, consisting of five treatments and five replicates. Each replicate consisted of five explants in different concentrations of sodium ampicillin and chloramphenicol for twenty minutes. Antibiotics were added separately to the culture medium at concentrations of 0, 5, 10, 15 and 20 mg L -1 . The data were analyzed using ANOVA and the means were compared by F test and regression analyses. We evaluated the percentage of contamination by bacteria, fungi and oxidation of the explants. The results showed that antibiotics had control over endogenous contaminants in ‘Thap maeo’ banana explants. The concentration of 20 mg L -1 of each antibiotic reduced in 70% the incidence of bacteria and fungi.