Efficient production of celery embryos and plantlets released in culture of immobilized gel beads

Celery embryos and plantlets were found to be selectively released in a culture of immobilized Ca-alginate gel beads in which celery callus was entrapped under regeneration conditions. We studied the feasibility of use of this process for celery embryogenesis in an artificial seed system. The cells released from the gel beads were larger than those obtained in suspension culture. The optimal concentration of alginate gel for embryo and plantlet production was 2% for the immobilized cell culture. Considering the maintenance of the gel bead structure and detrimental effect of CaCl₂ on plantlet development, 5 mM CaCl₂ supplementation gave the best result in terms of the number of heart and torpedo embryos and plantlets. The ratio of the number of heart embryos, torpedo embryos and plantlets to total number of cells in the immobilized cell culture was higher than that in the suspension culture. Repeated batch culture with 5 mM CaCl₂ provided long-term (more than 154 d) embryo and plantlet production without gel beads disruption. Productivity of plantlets in the immobilized cell culture with 5 mM CaCl₂ was 2.2-fold as high as that in the suspension culture.