Optimizing Somatic Embryogenesis and Biomass Proliferation in Narcissus L. ‘Carlton’ Callus Lines Using Solid and Liquid Media

Somatic embryogenesis (SE) in Narcissus offers significant potential for both horticultural propagation and pharmaceutical applications. In this study, embryogenic callus lines derived via primary and secondary SE were evaluated under different in vitro conditions to assess the effects of medium type (liquid vs. solid) and composition (proliferation vs. regeneration) on biomass growth and somatic embryo formation. Lines derived from primary SE (LC1–LC4) were less efficient compared to those obtained through secondary SE (LC5–LC7). Cultures cultivated in liquid proliferation medium for eight weeks showed a greater biomass accumulation than those grown on solid medium. Multivariate analyses revealed distinct growth patterns and responses to medium type among the callus lines. The LC5 and LC7 lines formed a separate cluster characterized by superior biomass proliferation and embryogenic competence. An eight-week culture in a liquid proliferation medium followed by a transfer to a solid medium of the same composition resulted in the highest somatic embryo yield in the LC5 line (54.4 embryos per 0.5 g of callus). Under the same conditions, the LC7 line showed the highest biomass growth (a 23.4-fold increase), but its embryogenic response was more effectively stimulated when the callus was initially proliferated on a solid medium and then transferred to a regeneration medium.