Callus Induction and Subculture of Taxus media var.hickss

The tender stems and leaves of Taxus media var.hickss were used as explants.The basic medium MS was used for callus induction,MS and B5 for callus subculture respectively.Different concentrations and combinations of cytokinin(6-BA,TDZ,KT,2-ip),auxin(NAA and 2,4-D) and darkening inhibitors(activated charcoal,vitamin C and lactalbumin hydrolysate) were added to the basic media.The results indicated that the tender stems had strong merisis ability,and more effective than leaf in inducing callus.The rate of callus induction was 100% when the tender stems were cultured in MS+TDZ0.002 mg/L+NAA1.0 mg/L,MS+TDZ0.002 mg/L+2,4-D1.0 mg/L,MS+TDZ0.002 mg/L+NAA1.0 mg/L+2,4D1.0 mg/L and MS+KT1.0 mg/L+2,4-D1.0 mg/L+NAA1.0 mg/L.These callus grew rapidly and had a fine quality which was good for next subculture.The medium B5+KT1.0 mg/L +2,4-D2.0 mg/L+NAA1.0 mg/L was optimum for callus subculture,and the proliferation coefficient was 5.2 every 30d.Subculture media with activated charcoal 500 mg/L,vitamin C 1000 mg/L or lactalbumin hydrolysate 1000 mg/L could inhibit the darkening of callus to some extent.