Protoplast development of Petalonia binghamiae (Phaeophyta, Scytosiphonaceae) protoplast culture of P. binghamiae

Protoplasts were isolated from gametophytic thalli of Petalonia binghamiae in February 1995 and January 1999, then were cultured at 15 deg C under 14 h light (40 micto mol/square m/s) or 10 h light (20 micro mol/square m/s). The rate of differentiated colonies was counted on the basis of protoplasts in the February experiment. The epidermal protoplasts differentiated into a spherical cell chain and a protonemal filament. The rates of the two types were not affect by two different lighting conditions, and were 15 - 18% (fifth day) and 0.3 - 0.8% (tenth day), respectively. The cortical protoplasts were isolated at only January thallus (2.1% per total protoplasts), and a part of them grew into a spherical cell chain. The gametophytic thalli were regenerated from protonemal filaments in all culture (0.1%).