“…Direct shoot induction is more prevalent in peony in vitro culture with several successful cases reported for both herbaceous peony (Hosoki et al, 1989;Gabryszewska, 1998) and tree peony (Bouza et al, 1994a, b;Kong and Zhang, 1998). Buds, shoot tips, nodal stem, petioles and leaf segments can be used for direct shoot induction; the highest frequency of shoot induction has been found in vegetative axillary buds or shoot tips (Hosoki et al, 1989;Orlikowska et al, 1998;Guo, 2001;Hu et al, 2003;Tian et al, 2010). Many methods were reported to enhance axillary shoot formation, such as the addition of thidiazuron (TDZ) at very low concentrations (0.01 to 0.04 mg l -1 ) to the medium containing a mixture of 6-benzyladenine (BA) (1, 2 and 4 mg l -1 ) + 6-γ-γ-dimethylaminopurine (2iP) (1, 2 and 4 mg l -1 ) + kinetin (Kin) (1, 2 and 4 mg l -1 ), a longi-tudinal shootsplit method in subculture (Hosoki et al, 1989;Gabryszewska, 1998) and manipulation of the light spectral quality under photoautotrophic conditions (Ding et al, 2010).…”