The shoot tips were cultured on SIM under the conditions specified
above, for 4 weeks. The cultures were routinely subcultured at 4 week intervals
to induce multiple shoot formation. After being cultured for 4 weeks, the microshoots
obtained from the SIM were individually excised and transferred to SIM,
supplemented with various concentrations of peptone (0, 1, 1.5, and 2%) or
silver nitrate (0, 3, 4 and 5 mg/l). After being cultured for a further 6 weeks, the
extent of multiple shoot formation and the number of shoots per explant was
recorded.