Abstract
In Pteris vittata L., callus formation was induced in young gametophytes by dark-culturing on the complex medium. Calli could readily be subcultured and maintained on the same medium. One of thus obtained calli is characterized by extreme friableness.
Friable callus tissues placed in liquid medium in the test tube with agitation produce small tissue pieces and a suspension consisting of cell aggregates and isolated cells. When a suspension was distributed on the surface of the complex medium, large calli were re-formed. When a suspension was placed on the defined medium devoid of organic substances, gametophytes differentiated.
The development of mature gametophytes from cell aggregates or directly even from isolated single cells was described in detail. The development of gametophytes from isolated cells resembled to the pattern of spore germination in Pteris vittata. The gametophytes cultured were grown up to the formation of sex organs and sporophyte formation.
