ABSTRACT
Objective: To establish the callus culturing system of embryos in Sophora japonica, and to analyze the contents of isoflavones in callus. Methods: Through adding the plant growth regulators of different kinds and at different concentration, the optimal media for callus induction, suspension cell culture, and the highest isoflavone content were obtained. Results: The optimal medium for callus induction of embryos in S. japonica was B5 + 2, 4-D (1.0 mg/L) + 6-BA (0.2 mg/L) + sucrose (20 mg/L). In solid medium, the callus was growing rapidly after 7 d, and the yield reached to the highest on the day 35 (fresh weight 7.4137 g), but the isoflavone content had no significant changes. In suspension culture, the yield of callus reached to the highest on the day 24 (fresh weight 11.563 8 g), and the callus turned into decline phase after 24 d, in which the fresh and dry callus weights were descending. With continuous culture, the cells were browning gradually, aging, and dying at last, but the isoflavone content was opposite to growth curve, and reached its lowest point (4.826 mg/g) on the day 24. Conclusion: The induction and cultivation of embryos callus in S. japonica and the isoflavone content have a larger correlation with the plant growth regulators of the kinds and the concentration.