Growth and Secondary Product Formation of in vitro Cultures from the Liverwort Reboulia hemisphaerica

Reboulia hemisphaerica has been cultivated on Gamborg B 5 medium with various sugars. Differentiated cultures grew best on agar medium with the addition of 0.5% sucrose and a light regime of 18 h light/6 h dark. Callus was induced either by a combination of phytohormones (2 mg/1 α-naphthylacetic acid + 1 mg/1 kinetin) or by 4% glucose. The differentiated cultures on agar produced sesquiterpenes in a tenfold increased amount compared to undifferentiated suspension cultures. Cultures kept in dark produced no sesquiterpenes, but 5-hydroxy-7, 8,4'-trimethoxyflavone was present whereas apigenin-7, 4'-dimethylether was the only flavonoid in cultures cultivated in the light.