Indução de calogênese em explantes foliares de mandioca em resposta à suplementação exógena de auxinas

Abstract

The induction of callogenesis in cassava depends significantly on its genotype. Thus, it is necessary to study the specific varieties of cassava in order to improve the techniques involved in the callogenesis process. This work aims to evaluate the effects of different types and concentrations of auxins in combination with 6-benzylaminopurine (BAP) on the callogenesis induction from leaf explants of the BRS Kiriris cassava variety. The experimental design was completely randomized, in a 3 x 3 factorial scheme, in which three auxins (naphthaleneacetic acid - NAA, indoleacetic acid - IAA and indolebutyric acid - IBA) were used in concentrations of 0.25, 0.5 and 1.0 mg L-1, with five replicates. A control treatment was performed, without the addition of phytoregulators. After a 60-day in vitro culture, the percentage of calli formed, the morphology of callus, number of calli, expansion, fresh weight and callus dry mass were evaluated. Excepting the control treatment, calogenesis was confirmed in all treatments, with a variation of 73 to 100% of callus formation. The IBA addition in concentrations of 0.5 and 1.0 mg L-1 provided the highest number of callus 1.78 and 1.77 calli, respectively. The NAA supplementation was determinant for the greatest expansion (12.09 mm) and fresh (515.00 mg) and dry mass (344.00 mg) of the calli. Therefore, calogenesis in leaf explants of the BRI Kiriris cassava variety can be induced by the use of NAA, IAA and IBA auxins in combination with BAP.