Effects of Hormone on Callus Induction and Subculture for Ginkgo biloba

Effects of hormone on callus induction and subculture were studied.Leaf and root of plantlets from species of fushou were used to establish callus cultures using MS medium with various hormone regimes:2,4-D (3.0 mg/L) with KT ( 1.0 and 5.0 mg/L);NAA (1.0 mg/L) with KT (0.5 and 1.0 mg/L);NAA (3.0 mg/L) with KT (1.0 mg/L).All in vitro cultures were incubated under 16 h photoperiod or dark and temperature (25±1) ℃.Callus have been obtained from all treatments using two kind explants,but their growth was severely limited under dark conditions when subcultured.Medium supplemented with 3.0 mg/L 2,4-D and 5.0 mg/L KT produced the overall highest weight for both leaf-derived and root-derived callus production.Chlorophyll content was used as an indicator to evaluate and confirm the best medium for callus production and long-term maintenance.Callus in medium supplemented with NAA and KT yielded less variation in color and appearance of callus.Medium with 1.0 mg/L NAA + 1.0 mg/L KT and 1.0 mg/L NAA + 0.5 mg/L KT were selected for callus production and long-term maintenance for leaf-derived and root-derived callus,respectively.