The present investigation was conducted to develop a protocol for rapid and efficient in vitro clonal propagation of Cichorium intybus L. Efficient shoot regeneration of Cichorium intybus L. from embryogenic callus cultures has been obtained using thidiazuron (TDZ). In vitro nodes have been used as explant and cultured on MS medium supplemented with different phytohormonal concentrations and combinations. TDZ/IAA treatments resulted in faster shoot regeneration than all other phytohormonal combinations used. The most effective treatment for regeneration and multiplication (144.3±1.90) per explant was found on MS + TDZ (1µM) + IAA (5.5µM) which was much higher than previous studies recorded for Cichorium intybus L., most likely due to the high inductive effect of TDZ. In the present study, auxins such as IBA, IAA and NAA were found to have a definite role in promoting floral bud formation. For in vitro flowering, the response of IBA was found better than IAA and NAA. Floral organs developed on various concentrations of NAA, but did not open at all. IBA (0.5µM) produced 2.9±0.22 number of floral buds/explant, out of which 1.5±0.31 number of flowers/explant developed. Effect of different sugars like glucose, sucrose, fructose and maltose were used at different concentrations (3%, 4% and 6%) for various morphogenetic responses. The shoots rooted efficiently on MS medium supplemented with different concentrations of IAA. Plantlets obtained were transplanted in small pots for hardening which showed 40-60% survival rate.
Keywords: In vitro flowering, Micropropagation, Phytohormones