Effects of different hormones on organogenesis in vitro of some varieties of cassava (Manihot esculenta CRANTZ) grown in Senegal

Cassava (Manihot esculenta) is a perennial euphorbiaceous shrub grown mainly for its starchy tubers and its leaves rich in protein. The most known method of propagation of this crop is the classical cuttings’ planting. However, in vitro propagation appears most useful and permits to obtain high quantity of healthy vegetable material in a short period. In this work, it was to study the impact of different hormones on the organogenetic capacities in vitro of five cassava varieties cultivated in Senegal. Axillary uninodal sections were disinfected and cultured in Murashige and Skoog (MS) basal medium added or not of different concentrations (0.1, 0.5 and 1 mg/L) of auxin (α-naphthalene acetic acid (NAA)) or cytokines (benzyl aminopurine (BAP) and kinetin). Best shoot growth and rooting was observed in MS medium containing 0.1 mg/L kinetin with normal development of the leaves. Highest proliferation of shoots and leaves was obtained with medium MS + BAP 1 mg/L. Callus formation was observed in all media containing hormone but most in MS + NAA 1 mg/L. This work proposes a rapid and economic technique for cassava multiplication.   Key words: Organogenesis in vitro, cassava, varieties, hormones, Senegal.