Gibberellins: Their Effect on Antheridium Formation in Fern Gametophytes.

Gametophytes of the fern Anemia phyllitidis respond to seven different gibberellins (A(1), A(3); A(4), A(5), A(7), A(8), and A(9)) by forming antheridia. Gibberellin A(7) is active at concentrations as low as 5 X 10(-10) g/ ml. Species from two of the three other genera in the family Schizaeaceae respond similarly to gibberellin A(3). In contrast, nearly 40 species from 7 other families of ferns do not develop antheridia when supplied with gibberellin.