You can manage bookmarks using lists, please log in to your user account for this.
Media type:
E-Article
Title:
Cryptochlorophyllous Spores in Ferns: Nongreen Spores that Contain Chlorophyll
Contributor:
Sundue, Michael;
Vasco, Alejandra;
Moran, Robbin C.
imprint:
University of Chicago Press, 2011
Published in:International Journal of Plant Sciences
Language:
English
DOI:
10.1086/662071
ISSN:
1537-5315;
1058-5893
Origination:
Footnote:
Description:
<p>In terms of color, fern spores have traditionally been classified as either green or nongreen. This study reports a new kind of spore, here termed “cryptochlorophyllous.” Such spores contain chlorophyll but do not appear green when examined with either the naked eye or a light microscope. Epifluorescence microscopy was used to detect chlorophyll in cryptochlorophyllous spores. To test one aspect of the reliability of this method, we examined whether chlorophyll degradation over time would give false negative results. We found that in two species with green spores (<italic>Osmundastrum</italic>
<italic>cinnamomeum</italic>and<italic>Terpsichore</italic>
<italic>asplenifolia</italic>), fluorescence weakened with but could still be detected in specimens that were 110 yr old. We surveyed the spores of species in three fern genera under white light and with epifluorescence microscopy. Under white light, green spores were seen in 10 (26%) of 39 species of<italic>Elaphoglossum</italic>, two (17%) of 12 species of<italic>Lomariopsis</italic>, and seven (25%) of 28 species of<italic>Pleopeltis</italic>. When spores from the same species were examined with epifluorescence microscopy, fluorescence was detected in 22 (56%) of 39 species of<italic>Elaphoglossum</italic>, 10 (83%) of 12 species of<italic>Lomariopsis</italic>, and 12 (42%) of 28 species of<italic>Pleopeltis</italic>. We also found conflicting results in nine of the 33 species represented in our study by more than one specimen. In these species with conflicting results, at least one specimen fluoresced whereas the other(s) did not. The specimens that failed to fluoresce might have been collected and dried before the chloroplasts in its spores had developed, or they may represent infraspecific variation in this characteristic. Chlorophyll-containing spores have probably been overlooked in<italic>Elaphoglossum</italic>and<italic>Lomariopsis</italic>because the dark perispore obscures the green contents of the cell. In some species of<italic>Pleopeltis</italic>, such spores have probably been overlooked because of their paleness and the short duration of their greenness. Chlorophyll-containing spores are probably more widespread than is currently suspected, especially in clades known to contain both green and nongreen spores. Overall, the dichotomy of fern spores into green and nongreen is too simplistic. It must be investigated experimentally whether cryptochlorophyllous spores behave like visibly green spores in terms of germination and viability times.</p>