A new antheridiogen from the fern Pityrogramma calomelanos (L.) Link

Abstract

A new antheridiogen from Pityrogramma calomelanos of the family Polypodiaceae (Sensu Bower) has been extracted and tested on Pityrogramma calomelanos, Onychium siliculosum (Desv) C. chr, and Onychium japonicum (Thbg) Kze. The antheridiogen, here designated as Apit, did not produce uniform effect on the species tested. It promotes dark germination in all, but induces antheridia only in Pityrogramma calomelanos and Onychium siliculosum under light and dark conditions. The antheridium-inducing capacity of Apit is markedly different on the two ferns, being more vigorous under light condition in Pityrogramma calomelanos and less in Onychium siliculosum. Contrary to this, more antheridium-bearing prothalli have been counted in the latter under darkness. Higher dilutions are less effective in both. Dark germination has been found most effective in case of Onychium japonicum. The results indicate that the intensity of the effect of antheridiogen varies under different conditions and between species of the same genus. Also, an antheridiogen is not specific in the induction of antheridia or dark germination of spores, but it may initiate any of the two or both. © 1952 Indian Academy of Sciences.