Stamen-less inflorescence proliferation of Bambusa edulis

After 6 years of subculture in the presence of 0.1 mg/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 (0.1 mg/l) and benzyladenine (1 mg/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 5 mg/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.