Stamen-less inflorescence proliferation of Bambusa edulis

After 6 years of subculture in the presence of 0.1mg/l thidiazuron (TDZ), a somaclonal variation of Bambusa edulis, vse had lost its capability to form stamens. The inflorescences were used to establish stamen-less inflorescence proliferation. In addition to the absence of stamens, the vse inflorescence had a longer palea and fewer trichromes on the surface than that of the wild type. In medium component studies, cytokinins were found to be essential for inflorescence proliferation, with TDZ (0.1mg/l) and benzyladenine (1mg/l) being the most efficient. Inflorescences were unable to proliferate in medium containing an auxin, although root formation occurred in the presence of indole-3-butyric acid and naphthaleneacetic acid (NAA). The basal MS medium supplemented with 5mg/l NAA was the most efficient for inducing root formation, with 11% (5/45) of the inflorescences generating vegetative shoots in this medium. One of the regenerated shoots flowered after a 2 months culture. Calli formed in medium supplemented with picloram and 2,4-dichlorophenylacetic acid. None of the plant regulator treatments could restore the capability to form stamens.