Red light (R) stimulates an increase in the total concentration of intracellular calcium in the spores of Onoclea sensibilis L. as determined by atomic absorption spectroscopy. Subsequent exposure to far-red light inhibits the R-induced increase in intracellular calcium. The majority of the increase occurs 5 minutes after the onset of irradiation. The calcium antagonist, La(3+), inhibits both g...

This study examined mutations expressed in haploid fern gametophytes derived from spores collected in the wild in order to assay for the presence of mutagenic compounds in natural environments. Gametophytes of the fern Onoclea sensibilis were cultured from spores collected in 14 natural populations around the region of Montreal, Quebec, Canada. Most of the populations grew in soils exposed to s...

The physiological nature of photoinduced germination of Onoclea sensibilis L. spores was investigated by temporarily applying a range of temperatures, particularly 40 C, before and after short light treatment. Controls were germinated at 25 C.The preinduction phase, during which photosensitivity is maximally developed in the dark, is sensitive to temperature. Treatment at 40 C for 8 or more hou...

Fern (Onoclea sensibilis) gametophytes when grown in the dark form a linear file of cells (one-dimensional) called a protonema. In the light two-dimensional growth occurs which results in a heart-shaped prothallus one cell thick. The objective of this paper is to relate the most common pattern of cell division observed in developing gametophytes to the formation of the plasmodesmatal network. S...

Dopp (1) demonstrated that the extract from mature prothalli of the fern species Ptcridiwtn1 aquiilinunil (L.) Kuhln hastened the onset of antheridium formation in young prothalli of this species by several days and in the prothalli of Dryopteris filixwwlas (L). Schott by several weeks. Dopp's conclusion that the prothalli of P. aquilinit elaborate a specific antheridium-inducing factor was con...