LAUSR

An efficient protocol for somatic embryogenesis and plant regeneration from rhizome explants of Gloriosa superba L. was developed using various plant growth regulators (PGRs), Ulva lactuca extracts (ULE), and phycomolecule-coated U. lactuca silver nanoparticles (ULAgNPs). Callus was initiated from rhizome explants on the Murashige and Skoog (MS) medium supplemented with various concentrations of 2,4-dichlorophenoxyacetic acid (1.0–5.0 mg L−1), α-naphthaleneacetic acid (NAA) (0.5 mg L−1), ULE (10–50%), and ULAgNPs (0.1–0.5 mg L−1). Callus was cultured on MS medium fortified with various concentrations and combinations of 6-benzylaminopurine (BAP) (0.5–2.5 mg L−1), kinetin (KIN) (0.5–2.5 mg L−1), ULAgNPs (0.1–0.5 mg L−1), and 20% ULE along with 0.5 mg L−1 NAA for the development of somatic embryos (SEs). The maximum percentage of embryo maturation (100%) was observed on the medium containing 0.5 mg L−1 ULAgNPs, 2.0 mg L−1 BAP, 0.5 mg L−1 abscisic acid (ABA), 0.5 mg L−1 silver nitrate (AgNO3), and 20% ULE. The highest percentage of embryo germination (86.1%) was noticed on the MS medium containing 0.3 mg L−1 ULAgNPs, 5.0 mg L−1 gibberellic acid (GA3), 2.0 mg L−1 BAP, 0.5 mg L−1 adenine sulfate (AdS), and 20% ULE. Well-rooted plantlets were successfully acclimatized in the greenhouse with 70% survival rate. Results suggest that U. lactuca extract-derived silver nanoparticles could be used as biostimulants for the enhancement of somatic embryogenesis and plant regeneration rate in G. superba.