Effect of dark incubation in germination of indirect date palm somatic embryos and conversion into plantlets

All studies on date palm somatic embryogenesis have focused on germination in the presence of light while neglecting germination in darkness, which mimics the germination process of zygotic embryos within seeds. To improve the date palm micropropagation protocol, we investigated the effects of light and darkness incubation on the germination of indirect date palm somatic embryos and their subsequent conversion into plantlets. Darkness incubation emerged as a pivotal factor in the germination of indirect date palm somatic embryos and their successful conversion into plantlets. Darkness incubation significantly decreased the time required for the conversion of indirect somatic embryos into plantlets, halving the duration from 24 weeks to only 12 weeks. The micropropagation protocol was modified, consolidating the previous two distinct stages of germination and elongation under light incubation into a single stage under darkness incubation. These findings modified the protocol and significantly reduced the overall duration of the date palm micropropagation protocol.