Am. J. Bot. Join BSA Today!
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Whittier, D. P.
Right arrow Articles by Braggins, J. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Whittier, D. P.
Right arrow Articles by Braggins, J. E.
Agricola
Right arrow Articles by Whittier, D. P.
Right arrow Articles by Braggins, J. E.
(American Journal of Botany. 2000;87:920-924.)
© 2000 Botanical Society of America, Inc.

Observations on the mature gametophyte of Phylloglossum (Lycopodiaceae)1

Dean P. Whittier4,2 and John E. Braggins3

2 Department of Biology, Vanderbilt University, Nashville, Tennessee 37235 USA; and 3 School of Biological Sciences, University of Auckland, Private Bag 92109, Auckland, New Zealand

ABSTRACT

Mature, gametangia-bearing photosynthetic gametophytes of Phylloglossum can be grown from the nonphotosynthetic, cylindrical, negatively gravitropic immature stages in illuminated axenic culture on a nutrient medium with or without 0.2% glucose. The gametangial-bearing region of these gametophytes, the photosynthetic crown, grows horizontally from the apex of the immature cylindrical stage. At maturity the photosynthetic crown is thickened and bilaterally symmetrical. It is usually narrow and bean-shaped with dorsal and ventral regions. Occasionally, the ventral region becomes thicker and the crown is deltoid in cross section. The dorsal edge or ridge of the crown is the gametangial region with archegonia and antheridia. The gametangia are often hidden because they are interspersed among numerous uni- or bicellular paraphyses. The lateral surfaces below the gametangial region lack outgrowths, and the ventral region is covered with long rhizoids. The apical meristem at the anterior end of the crown is overarched by the developing dorsal tissue of the gametangial ridge. The lower derivatives of the meristem form the ventral region with rhizoids. Phylloglossum gametophytes are unusual because their mode of organic nutrition changes from mycorrhizal to photosynthetic during ontogeny.

Key Words: development • gametophyte • Lycopodiaceae • morphology • Phylloglossum • pteridophyte






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2000 by the Botanical Society of America, Inc.