Comparative studies of cytokinins on in vitro propagation of Bacopa monniera

A mass in vitro propagation system for Bacopa monniera (L.) Wettst. (Scroph ulariaceae), a medicinally important plant, has been developed. A range of cytokinins have been investigated for multiple shoot induction with node, i nternode and leaf explants. Of the four cytokinins (6-benzyladenine, thidia zuron, kinetin and 2-isopentenyladenine) tested thidiazuron (6.8 muM) and 6 -benzyladenine (8.9 muM) proved superior to other treatments. Optimum adven titious shoot buds induction occurred at 6.8 muM thidiazuron where an avera ge of 93 shoot buds were produced in leaf explants after 7 weeks of incubat ion. However, subculture of leaf explants on medium containing 2.2 muM benz yladenine yielded a higher number (129.1) of adventitious shoot buds by the end of third subculture. The percentage shoot multiplication (100%) as wel l as the number of shoots per explant remained the high during the first 3 subculture cycles, facilitating their simultaneous harvest for rooting. In vitro derived shoots were elongated on growth regulator-free MS medium and exhibited better rooting response on medium containing 4.9 muM IBA. After a hardening phase of 3 weeks, there was an almost 100% transplantation succe ss in the field.