Improvement of somatic embryogenesis and plant regeneration of seven date palm (Phoenix dactylifera L.) cultivars: Effect of cytokinins and activated charcoal

Abstract: This study presents a procedure for the rapid development of a large number of somatic embryos and shoots from seven date palm cultivars (Barthamuda, Sakkoty, Malkaby, Shamia, Khalas, Barhee and Medjool). Clusters of leaf meristem explants were cultured on Murashige and Skoog medium supplemented with 0.1 mg/L naphthalene acetic acid and cytokinins (benzyl adenine, kinetin or 2-isopentenyl adenine) at 0.05 or 0.1 mg/L, in the presence or absence of activated charcoal. Regeneration to newly formed embryos and shoot formation was significantly (P<0.05) promoted in all cultivars using a culture medium with 0.05 mg/L benzyl adenine in the absence of activated charcoal. The presence of charcoal was inhibitory to shoot formation in all cases, except on the medium with 0.05 mg/L benzyl adenine, where it stimulated 33% shoot formation. This medium plus activated charcoal is therefore the recommended one for shoot formation. The number of somatic embryos and shoots generated was greatest with cultivars Barthamuda, Barhee and Sakkoty, while Medjool had the lowest number. The healthy shoots were suitable for acclimatization to form plantlets in soil.