Evaluation of the growing regulator effect on the in vitro regeneration of five cassava cultivars (Manihot esculenta Crantz).

The cassava is an important source of carbohydrates and food energy for millions of people in the tropic. Nonetheless, traditional methods of propagation present a low multiplication rate. In order to cover the needs of materials with desirable characteristics by propagation, it is required to implement massive multiplication techniques, which is possible through tissue culture. The objective of this work was to evaluate the growth regulators effect on the in vitro regeneration of five cassava cultivars from CIAT. Five cultivars were used: BRA 383, PER 183, CM 523-7, CM 3306-4 y SM 1565-15. Two solid culture media were used that contain mineral salts of Murashige and Skoog (19632) were used. This media were differentiated by the following hormonal combination: M1 (ANA 0.02 mg L-1 + AG3 0.05 mg L-1) and m2 (ANA 0.02 mg L-1 + AG3 0.05 mg L-1 + BA 0.5 mg L-1). For the in vitro multiplication of the cultivars, the media M1 was the best inductor of regeneration for the most cultivars evaluated because there was a vigorous growth of buds and roots. In the other hand, the media m2 produced relatively poor development of microcutting (shoots and root growth) in most of the evaluated cultivars. A differential genotypes response was observed in the in vivo development of plantlets. The cultivars CM-523-7, PER-183 and BRA 383 showed the best perform for the most variables evaluated: high vitroplants (growth rate), higher length and number of microcutting and good root system.