Effects of TDZ on Polyamines Concentration Changes during the Construction of Floral-buds in Derooted Seedlings of Dendrobium officinate Kimura et Migo in vitro
Abstract:The effects of tridiazuron (TDZ) on endogenous polyamines concentration changes in derooted seedlings of Dendrobium officinate Kimura et Migo in vitro and the construction of floral-buds were researched in this experiment, in which MS basal medium supplemented with TDZ was used. It was found that the formation rate of floral-bud in derooted seedlings cultured on MS mixed with 0.1 mg·L-1 TDZ accounted for 21.1%, whereas the control was 0. During the construction of floral-bud, the endogenous concentrations of Spd, Spm and the ratios of Spd to Put, Spm to Put in top shoots of derooted seedlings cultured on MS mixed with 0.1 mg·L-1 TDZ exceeded those in the control, and remarkably exceeded that of control when the floral-bud emerged. In addition, the levels of Put and DAP in top shoots of derooted seedlings were apparently lower than that in the control. It was seen that exogenous TDZ could promote the construction of floral-bud by means of the changes of endogenous polyamines concentration and its ratio in D.officinate Kimura et Migo.