Structure and function of spores in the aquatic heterosporous fern family Marsileaceae
Date
2002-01-01
Authors
Journal Title
Journal ISSN
Volume Title
Repository Usage Stats
views
downloads
Citation Stats
Abstract
Spores of the aquatic heterosporous fern family Marsileaceae differ markedly from spores of Salviniaceae, the only other family of heterosporous ferns and sister group to Marsileaceae, and from spores of all homosporous ferns. The marsileaceous outer spore wall (perine) is modified above the aperture into a structure, the acrolamella, and the perine and acrolamella are further modified into a remarkable gelatinous layer that envelops the spore. Observations with light and scanning electron microscopy indicate that the three living marsileaceous fern genera (Marsilea, Pilularia, and Regnellidium) each have distinctive spores, particularly with regard to the perine and acrolamella. Several spore characters support a division of Marsilea into two groups. Spore character evolution is discussed in the context of developmental and possible functional aspects. The gelatinous perine layer acts as a flexible, floating organ that envelops the spores only for a short time and appears to be an adaptation of marsileaceous ferns to amphibious habitats. The gelatinous nature of the perine layer is likely the result of acidic polysaccharide components in the spore wall that have hydrogel (swelling and shrinking) properties. Megaspores floating at the water/air interface form a concave meniscus, at the center of which is the gelatinous acrolamella that encloses a "sperm lake". This meniscus creates a vortex-like effect that serves as a trap for free-swimming sperm cells, propelling them into the sperm lake.
Type
Department
Description
Provenance
Subjects
Citation
Permalink
Published Version (Please cite this version)
Publication Info
Schneider, H, and KM Pryer (2002). Structure and function of spores in the aquatic heterosporous fern family Marsileaceae. International Journal of Plant Sciences, 163(4). pp. 485–505. 10.1086/340736 Retrieved from https://hdl.handle.net/10161/21863.
This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.
Collections
Scholars@Duke
Kathleen M. Pryer
Unless otherwise indicated, scholarly articles published by Duke faculty members are made available here with a CC-BY-NC (Creative Commons Attribution Non-Commercial) license, as enabled by the Duke Open Access Policy. If you wish to use the materials in ways not already permitted under CC-BY-NC, please consult the copyright owner. Other materials are made available here through the author’s grant of a non-exclusive license to make their work openly accessible.