Floral induction in date palm seedlings (Phoenix dactylifera var. Deglet Nour) cultured in vitro

Abstract

Flower bud initiation in 5-month-old seedlings of date palm (Phoenix dactylifera L. var. Deglet Nour) was studied under controlled conditions. Normally inflorescence formation in mature plants takes 8 to 10 years. In juvenile plants inflorescence formation was induced in a 16-h day at 28 °C, by a combination of 6-benzylaminopurine, indoleacetic acid, and glucose or sucrose. The present investigation has determined favourable cultural conditions for floral induction in date palm in vitro at a very early stage of ontogeny. Both male and female flowers were induced on young plants. Floral induction usually occurred only when root formation was completely inhibited. The apparent antagonism between root formation and floral development suggests a possible competition in the young plant for growth substances, although production of floral inhibitory substances from the root cannot be precluded. These observations on the induction of precocious flowering in date palm seedlings suggest a model of development, corresponding to neoteny, of this tree as an herb.