Callus induction, somatic embryogenesis, <em>in vitro</em> plantlet development and <em>ex vitro</em> transplantation of two date palm (<em>Phoenix dactylifera</em> L.) cultivars

Abstract

The protocol has been developed and standardized in two date palm (Phoenix dactylifera L.) cultivars. Protocol was cultivar and plant growth regulators dependant. Embryogenic callus from excised shoot tips was induced on MS medium supplemented with 2,4-D 100 mg/l. A combination of ά-naphthalene acetic acid and 6-benzyladenine (NAA 0.1 + BA 0.05) in MS medium multiplied callus 3-4 times followed by abscisic acid (ABA, 0.5 mg/l) treatment matures callus and accelerated the initiation of somatic embryos in both the cultivars. Treatment combination of abscisic acid (0.5 mg/l) + indole-3-butyric acid (IBA, 0.05 mg/l) in medium found effective in maturation of somatic embryos. Somatic embryos germinated and converted into plantlets in half strength modified MS medium containing different concentrations of IBA @ 0.1, 0.2, 0.3 mg/l and NAA @ 0.1, 0.2, 0.3 mg/l. At a higher concentration (0.3 mg/l), in vitro roots and leaves (plantlets) were developed while at lower concentrations, response was comparatively poor. Secondary hardened plants after primary hardening were transplanted in the field for assessing their field performance. The findings of this paper indicate that enhanced production of somatic embryos and their conversion into plantlets can be a potential source of alternative mass propagation of date palm.