At equimolar concentrations, all the treatments with BA,mT (except
10 μM), mTR and MemTTHP significantly increased shoot production
when compared to KIN. The optimum cytokinin concentration for
shoot production was 5.0 μM mT with 14.5 shoots regenerated per
explant (Fig. 1b). The number of adventitious shoots obtained at this
optimal mT concentration was significantly higher when compared at
an equimolar level to other cytokinins (except mTR) used in this study.
This indicates thatmT influences a high level of differentiation in shoot-tips
of C. album. Meta-topolin is potentially a highly active alternative to
BA and other cytokinins for C. album shoot production. The effectiveness
of mT has been attributed to its chemical structure which allows for the
production of O-glucoside metabolites (non-toxic and easily convertible
cytokinin storage form) from the hydroxyl group on the side chain
of mT as well as its rapid translocation in plant tissues (Kamínek et al.,
1987; Werbrouck et al., 1996).