Growth Regulation by Ethylene in Fern Gametophytes. Iii. Inhibition of Spore Germination

Abstract

Spores of Onoclea sensibilis were investigated for inhibition of germination by ethylene. A curve of germination against ethylene concentration indicated a “threshold” type of response, but percentage of spore germination was not influenced either by the density of the inoculum or by the presence of 1 % sucrose in the culture medium. Ethylene totally inhibited dark germination, but in white light reversal of inhibition was possible in about 50% of the germinating spores. Time‐course studies revealed that in imbibed spores ethylene inhibited germination in the first 3 ± 1 hr of illumination. Dose‐response curves of light intensity vs. germination indicated that the response to light differed in the presence and absence of ethylene. Recovery from inhibition was possible once ethylene was allowed to escape, and the rate of recovery was accelerated by light.

Factors Influencing Spore Germination and Early Gametophyte Development in Anemia mexicana and Anemia phyllitidis

“…In addition to light and GA-like compounds, other factors including the pH of the culture medium (2), ethylene (6) and calcium availability (30) have been shown to influence the ability of spores to germinate and the subsequent growth of gametophytes (20,25). In the present study, experiments were conducted to determine optimum germination conditions in order to use this as a bioassay for detection of compounds produced by gametophytes which stimulate spore germination in darkness.…”

Red Light Stimulates an Increase in Intracellular Calcium in the Spores of Onoclea sensibilis

“…Chlorine was analyzed as C1-after a Schoniger oxygen flask combustion followed by a coulometric titration with silver (15). Per cent germination was determined 48 h after irradiation by the acetocarmine-chloral hydrate method (8). Data are expressed as the mean ± two SE.…”

Gametófitos de Pleurosorus papaverifolius (Kunze) Fée (Aspleniaceae) y Cheilanthes glauca (Cav.) Mett. (Pteridaceae), dos helechos rupícolas sudamericanos

“…Los gametófitos extraídos de las placas fueron teñidos con hidrato de cloral-acetocarmín (Edwards & Miller 1972), montados en agua y observados en un microscopio óptico. También se realizaron observaciones en vivo.…”