Abstract
Leaf segments of Nymphoides indica, which is at risk of extinction, were cultured on MS medium containing
3% (w/v) sucrose and different concentrations of thidiazuron and naphthalene acetic acid. Multiple shoots
were produced in the primary culture and they were subcultured. From subcultured multiple shoots, plants
were regenerated. This means that making multiple shoots culture might be one of suitable ways for
propagation of rare or endangered plant species. Subcultured multiple shoots were cryopreserved in liquid
nitrogen after pre-freezing at -40℃. The survival rate after cryopreservation was as much as 70%, and
regrowth of tissues were observed.
