Comportement in vitro de bourgeons axillaires de type indéterminé du palmier dattier (Phoenix dactylifera)

Abstract

Indeterminate axillary buds excised from young offshoots of date palm (Phoenix dactylifera L.) developed into flowering or vegetative buds when cultured under different in vitro conditions. Floral induction was observed in explants cultured in the dark on Murashige and Skoog's medium supplemented with 50 g∙L−1 of sucrose and several auxins and cytokinins in a ratio favouring the auxins. In contrast, vegetative buds were obtained from explants cultured under a 16-h photoperiod on Murashige and Skoog's medium supplemented with 30 g∙L−1 of sucrose and 1 mg∙L−1 of indolebutyric acid. The results showed that numerous vegetative meristems can be produced from indeterminate buds cultured in vitro. The results also confirmed the observations made during an in vivo study of flowering and vegetative bud development. The importance of the nutritional contribution of the leaves surrounding the flowering buds was pointed out. Key words: Phoenix dactylifera, axillary buds, indeterminate buds, in vitro culture, floral state, vegetative state, morphogenesis.