Preliminary Study on Two-phase Culture of Tripterygium wilfordii Adventitious Root

Through two-phase culture, we studied the effects of culture time extension and volume percentages of dibutylphthalate (DBP) on growth and secondary metabolite content in the adventitious roots of Tripterygium wilfordii Hook. f.. Results showed that adventitious root growth increased 1.06-fold when the volume percentage of DBP was 6% and addition of organic solvent was on day 6. Triptolide content in the root was 1.40-fold higher when the volume percentage of DBP was 2% and addition of organic solvent was on day 8. Triptolide yield in the two-phase culture was 1.48-fold higher than that of the control when the volume percentage of DBP was 2% and addition of organic solvent was on day 2. Thus, DBP in the medium was suitable for triptolide accumulation, but alkaloid accumulation was inhibited significantly. The contents of wilforgine and wilforine in the adventitious roots and yields of wilforgine and wilforine per flask were all lower than that of the control, regardless of the concentration of DBP added to the medium or the extension of culture time.