Influence of growth regulators on callogenesis and somatic embryo development in date palm (Phoenix dactylifera L.) Sahelian cultivars.
This study provides a physiological analysis of somatic embryogenesis in four elite cultivars of date palms: Ahmar, Amsekhsi, Tijib, and Amaside, from the initial callogenesis to establishment and proliferation of embryogenic suspension cultures. Somatic embryos development and in vitro plants rooting were also studied. For each step, auxins and cytokinins concentrations were optimised. The primary callogenesis from leaf explants of seedlings appeared highly dependent on genotype. Ahmar (80%) and Amsekhsi (76%) appeared highly callogenic, whereas Tijib (10%) and Amaside (2%) produced low amounts of calluses. 2,4-Dichlorophenoxyacetic acid appeared favorable to the induction of primary callogenesis and its effect was enhanced by the addition of benzyl adenine or adenine sulfate. Secondary friable calli obtained from chopped granular calli were used to initiate embryogenic cell suspensions in media supplied with 2,4-dichlorophenoxyacetic acid. Suspension cultures showed a growth rate of fourfold after four subcultures in presence of 2,4-dichlorophenoxyacetic acid 2 mg/L. Our results showed that a seven-day transitory treatment with benzyl adenine 0,5 mg/L was necessary to optimize embryos development. Naphthalene acetic acid induced the development of primary orthogravitropic roots during embryos germination. The comparison with cytofluorometry of nuclear DNA amounts showed no significant difference in ploidy level between regenerated plants and seedlings.
Département de Biologie Végétale, Université Cheikh Anta Diop, BP 5005 Dakar-Fann, Senegal. djisane@refer.sn
Djibril
D
Sané
Frédérique
F
Aberlenc-Bertossi
Léopold Ibrahima Djitiningo
LI
Diatta
Badara
B
Guèye
Abdourahman
A
Daher
Maurice
M
Sagna
Yves
Y
Duval
Alain
A
Borgel
D028023:Arecaceae / Q000196:embryology* / Q000254:growth & development*; D010937:Plant Growth Regulators / Q000494:pharmacology*; D058439:Plant Somatic Embryogenesis Techniques / Q000379:methods*; D012639:Seeds / Q000187:drug effects / Q000254:growth & development*
D010937:Plant Growth Regulators