Effects of NO3– and BAP on organogenesis in tissue-cultured shoot primordia induced from shoot apices of Utricularia praelonga St. Hil.

The effects of NO3– and BAP on organogenesis in shoot primordia of Utricularia praelonga subcultured in B5 liquid medium were studied. In B5 liquid basal medium supplemented with 24.73 mM KNO3 and 2.0 mg/l BAP the subcultured shoot primordia continuously multiplied into numerous small, globular masses, while with dilution of the KNO3 to 3 mM organogenesis was promoted. Pulse treatment of the shoot primordia with 3 mM KNO3 in B5 liquid medium for 72 h and then transplantation to the B5 basal liquid-medium induced meristemoids in this tissue. When the shoot primordia regenerated meristemoids, they never reverted back into the proliferation cycle. The addition of BAP in the B5 liquid medium with 3 mM KNO3 regulated the differentiation rate of the stems and leaves in the meristemoids induced in the masses of shoot primordia. The control produced 3 parts stems to 1 part leaves; medium with 0.02 mg/l BAP regenerated approximately 2 parts stems and 1 part leaves; that of 0.20 mg/l BAP 1 part stems and 2 parts leaves; and medium with 2.00 mg/l BAP regenerated leaves only.