In vitro plant regeneration system for Cassia siamea Lam., a leguminous tree of economic importance

A method for rapid in vitro propagation of Cassia siamea Lam. using cotyledonary node explants, excised from 14-day old aseptic seedlings, has been established. Murashige and Skoog (MS) medium supplemented with different concentrations of 6-benzyladenine (BA), kinetin (Kn) and thidiazuron (TDZ) singly or in combination with auxins was used for regeneration studies. Among the single treatment of three cytokinins BA at 1.0 A mu M was found to be optimum for direct shoot regeneration as it induced an average of 8.20 +/- A 0.66 shoots per explant. The regeneration frequency further enhanced with the application of auxin along with optimal BA concentration. The highest frequency for shoot regeneration (90%), the maximum number of shoots per explant (12.20 +/- A 0.73) and the maximum shoot length (6.40 +/- A 0.07) cm were obtained on the medium consisted of MS + 1.0 A mu M BA + 0.5 A mu M NAA. Successful in vitro rooting was induced from cut end of the microshoots when placed on half-strength MS + IBA (2.5 A mu M). The regenerated shoots with well developed root system were successfully acclimatized and established in pots containing sterilized garden soil and garden manure (1:1) and grown under greenhouse conditions with 85% survival rate.