Vegetative multiplication of date palms from in vitro cultured inflorescences: effect of some growth regulator combinations and organogenetic potential of various cultivars

Explants from inflorescences of date palms from different female cultivars and one selected male clone were cultured on five growth regulator combinations.Shoot primordia formed mostly on Greshoff and Doy media containing: 0.5 mg L -1 of naphthalene acetic acid (NAA), 2 mg L -1 of 6-benzylaminopurine (BA) and 1 mg L -1 of 2-isopentylade- nine (2iP).Shoot multiplication occurred on the same medium, but plant growth and rooting were only obtained by a ten- fold reduction in cytokinin concentration or by an increase in NAA to 2 mg L -1 in combination with 1 mg L -1 2iP or 1 mg L -1 BA.Histological analysis of cultured explants revealed that buds originated from petal primordia.Percentages of reactive inflorescence explants in various media differed among cultivars examined.The technique offers great promise for vegetative propagation of date palms since several hundred plants could be obtained from a single inflores- cence, and each individual tree can produce several inflorescences annually.(© Inra/Elsevier, Paris.)micropropagation / Phoenix dactylifera L. / organogenesis / female and male inflorescences Résumé -Multiplication végétative du palmier dattier à partir de segments d'inflorescences cultivés in vitro : effet de différentes combinaisons hormonales et capacités organogénétiques de divers cultivars.Des fragments d'inflo- rescences appartenant à différents cultivars femelles de palmier dattier et à un clone mâle sélectionné ont été mis en cul- ture in vitro en présence de cinq combinaisons hormonales différentes.La formation des bourgeons et leur multiplication étaient meilleures sur le milieu Greshoff et Doy en presence de 0,5 mg L -1 d'acide naphtylacétique (ANA), 2 mg L -1 de 6-benzylaminopurine (BAP) et 1 mg L -1 de 2-isopentyladénine (IPA).