Effect of the combined use of two cytokinins in the multiplication and regeneration of adventitious banana buds cv. ‘Gros Michel’ (Musa AAA)

Abstract

In breeding programs it is important to have an efficient plants regeneration system. In the cultivar ‘Gros Michel’ (Musa AAA) it is difficult to obtain adventitious buds due to high apical dominance. The present investigation was developed with the objective of determining the effect of cytokinins on the multiplication and regeneration of adventitious buds in that cultivar. Three treatments were established with the combination of 6-BAP and TDZ and each of them separately. Sections of 0.4 mm2 of adventitious buds with one multiplication subculture were used. The number of adventitious buds and shoots formed by explant was quantified every 30 days. Subsequently, it were placed in a culture medium free of growth regulators and after 30 days the percentage of shoots regenerated by explant, the height of the shoot and the number of leaves emitted were evaluated. The results showed that with four subcultures in a culture medium with 6-BAP (2.0 mg l-1) and TDZ (1.0 mg l-1) were achieved 1.5 to 8.0 adventitious buds per explant with 92% regeneration and height greater than 2.0 cm without showing evidence of phenotypic changes. All of the above confirms that the use of these two cytokinins combined at lower concentrations and in a smaller number of subcultures provides greater possibilities for the adventitious buds formation, their multiplication and subsequent regeneration which will enable their use in the Genetic Improvement Programs of bananas.