ISSN:
1432-2048
Keywords:
Dryopteris
;
Germination (fern spore, phytochrome)
;
Phytochrome (spore germination)
;
Polystichum
;
Pteridophyta
;
Spore germination
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Spores of the ferns, Dryopteris filix-mas, D. paleacea and Polystichum minutum, sown on plain agar in quartz-distilled water, required several hours of red light in order to germinate. When, however, water agar was replaced by agar made up with a mineral nutrition medium, a single pulse of red light (about 1 min) was able fully to induce germination. Under these conditions spores became light-sensitive a few minutes after sowing. Thus, zero germination in dark controls was obtained only when all light was excluded immediately after sowing or when saturating far-red was given thereafter. The effect of the mineral medium was also obtained using low ion concentrations with an osmolality of less than 100 μmol l−1. Thus, a specific ion effect appears more probable than an unspecific osmotic effect. Species differences in light sensitivity and in dark-germination levels, as reported in the literature, might partly be the consequence of different culture media and of light acting at a very early stage after sowing, which hitherto was assumed to be still insensitive to light. On water agar as well as on mineral agar, the inducing effect of a single red pulse could be increased by the appropriate pretreatment, i.e. by preirradiation with red light for several hours, followed by a saturating pulse of far-red, the latter abolishing the direct inducing effect of the red preirradiation. The nature of both the ion-phytochrome interaction and the phytochrome-phytochrome interaction has not yet been analysed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00391026
