Physiological and Morphogenetic Studies of Fern Gametophytes and Sporophytes in Aseptic Culture. XII. Sporophyte Formation in the Dark- Cultured Gametophyte of Pteris vittata L.

In Pteris vittata L. apogamous sporophytes frequently arise from dark-cultured gametophytic tissues. The minimum requirement for sporophyte formation in the dark is an addition of sugar to the basal medium. Yeast extract, casein hydrolysate, wheat germ extract, tryptophan, indoleacetic acid (IAA), and gibberellic acid (GA3) promote sporophyte formation, while kinetin, 2,4-dichlorophenoxyacetic acid (2,4-D), and some amino acids are without effect or are inhibitory. Three phases in sporophyte differentiation are clearly discernible: gametophytic, initiative, and sporophytic phases.