High-efficiency somatic embryogenesis from leaf explants of Ornithogalum caudatum Ait

• First documented dual induction for both direct and indirect somatic embryogenesis in O. caudatum . • NAA-TDZ/BA combinations demonstrated synergistic efficacy in optimizing micropropagation. • Large-scale plantlet generation through direct somatic embryogenesis. Ornithogalum caudatum Ait ( O. caudatum ), a highly valued ornamental and medicinal species, holds notable commercial potential for bioprospecting industries. This study established both direct and indirect somatic embryogenesis (SE) pathways using leaf explants on Murashige and Skoog (MS) medium supplemented with plant growth regulators (PGRs). Leaf explants treated with 1.0–3.0 mg L⁻¹ auxin (α-naphthylacetic acid (NAA), indole-3-butyric acid (IBA) and dichlorophenoxyacetic acid (2,4-D)), and four types cytokinins (thidiazuron (TDZ), 6-benzyladenine (BA), kinetin (Kin), and zeatin (ZT)) directly or direct produced somatic embryos. IBA as the sole PGR optimally induced direct SE, yielding 16.3 ± 2.5 embryos per explant at 84.7 % frequency. Treatment with 2,4-D generated embryogenic calli via an indirect pathway, with subsequent SE induction peaking at 43.6 % (8.6 ± 1.5 embryos/explant). Cytokinin - auxin synergism markedly enhanced regeneration efficiency: 0.3 mg L⁻¹ NAA with 2.0 mg L⁻¹ TDZ or BA achieved maximal SE induction (100 % and 98.9 %, respectively) and embryo production (24.7 ± 1.8 and 22.5 ± 3.1 per explant). Gibberellic acid 3 (GA 3 ) promoted somatic embryo maturation. SE-derived plantlets exhibited 98.0 % survival during greenhouse acclimatization. This work established a trustworthy and efficient strategy for regeneration through direct and indirect SE pathways, enabling scalable propagation, genetic engineering, and germplasm conservation of this commercially valuable species.