CELL-WALL PIGMENT FORMATION OF IN-VITRO CULTURES OF THE LIVERWORT RICCIOCARPOS NATANS

The liverwort Ricciocarpos natans has been cultivated on Gamborg B5 me dium with different levels of ammonium, nitrate, phosphate and sucrose . The formation of the cell wall pigments riccionidin A and B was show n to be dependent on the level of these nutrients as well as on the in tensity of light. A decrease in nitrogen supply (mainly nitrate) induc ed the formation of both wall pigments, whereas phosphate and high lev els of sucrose inhibited the pigment synthesis. Decreasing the illumin ation rate led to lower anthocyanidin contents. Dedifferentiated cultu res also produced wall pigments, but their amount was much lower compa red to differentiated cultures.