Abstract: In order to establish a loose embryogenic callus induction system of Apium graveolens and obtain somatic embryogenesis, different explants of Apium graveolens were used to induce callus and somatic cell embryogenesis on the medium containing 2,4-D. The results showed that the hypocotyl of Apium graveolens as an explant can induce ideal callus tissue; The callus grew fastest on MS+0.5 mg/L KT+0.2 mg/L NAA+1.0 mg/L 2,4-D medium; Loose callus can be induced on MS+0.5 mg/L KT+0.5 mg/L 2,4-D medium; Transfer loose embryogenic callus tissue to MS+0.1 mg/L KT+0.5 mg/L 2,4-D medium, subculture every 15 days, and obtain loose embryogenic callus tissue after 3 subcultures; The loose embryogenic callus was transferred to MS+0.25 mg/L KT+0.25 mg/L 2,4-D medium and subcultured once every 15 days. After subculturing for three times, the Apium graveolens somatic cell embryos were obtained; After somatic embryos were transferred to 1/2MS medium, regenerated plants of Apium graveolens could be obtained after 45 days. This experiment successfully established the induction system of loose embryogenic callus and somatic embryogenesis of Apium graveolens, and obtained regenerated plants, which laid a certain foundation for in vitro mutation breeding of Apium graveolens somatic cell.

Key words: Apium graveolens, loose embryogenic callus, hypocotyl, somatic embryo