The changes in shoot regeneration potential of protocorm-like bodies derived from Lilium longiflorum young stem explants exposed to medium volume, pH, light intensity and sucrose concentration pretreatment

Abstract

SummaryAn efficient system has been developed for the in vitro shoot regeneration of Lilium longiflorum Thunb. by culturing pretreated protocorm-like bodies (PLBs) derived from young stem transverse thin-cell layers (tTCLs) exposed to various treatments of different medium volumes, pH, light intensity and sucrose concentrations. After 30.d culture in 50 ml plastic petri dishes containing Murashige and Skoog medium supplemented with 0.2 mg l–1 thidiazuron (TDZ), the explants formed PLBs in all treatments. PLBs with the highest fresh weight were obtained after 30.d of culture when explants were cultured on MS medium containing 0.2 g l–1 TDZ with either 25 ml volume, pH 6.1, 20 μmol m–2 s–1 light intensity, or with 30 g l–1 sucrose supplement. However, most shoot formation from PLBs was found using MS hormone-free medium with either 30 ml volume, pH 5.0, 40 μmol m–2 s–1 light intensity, or with 20.g l–1 sucrose after 30.d of culture. The highest shoot regeneration of L. longiflorum was derived from PLBs when explants were exposed to various media, indicating that the choice of explants and pretreatment in the medium with optimum volume, pH, light intensity and sucrose concentreation are needed.