Synchronization of Somatic Embryogenesis in a Carrot Cell Suspension Culture

Abstract
Synchronization of somatic embryogenesis was achieved in a carrot (D. carota L. cv. Kurodagosun) suspension culture by sieving the initial heterogeneous cell population, by density gradient centrifugation in Ficoll solutions and by subsequent repeated centrifugations at a low speed (50 g) for a short time (5 s), followed by transferring the cell clusters obtained, which were composed of 3-10 cells, to a medium containing zeatin (0.1 mM) but no auxin. The frequency of embryo formation reached more than 90%, and synchrony of the embryogenetic process was observed at least in the early stages of the process. The system established in the present work provides a useful system for biochemical research into the mechanisms of somatic embryogenesis.