You are not currently logged in.
Access JSTOR through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Developmental Anatomy of Light-Induced Root Nodulation by Zamia pumila L. Seedlings in Sterile Culture
David T. Webb
American Journal of Botany
Vol. 70, No. 8 (Sep., 1983), pp. 1109-1117
Published by: Botanical Society of America, Inc.
Stable URL: http://www.jstor.org/stable/2443280
Page Count: 9
You can always find the topics here!Topics: Nodules, Root cap, Daughter cells, Plant cells, Nodulation, Meristems, Plant roots, Cell nucleus, Parenchyma, Apical meristems
Were these topics helpful?See somethings inaccurate? Let us know!
Select the topics that are inaccurate.
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
The developmental anatomy of Zamia pumila L. root apices was studied during light-induced nodulation. Dark-grown roots had an apical organization identical to that of other cycads and similar to that of other gymnosperms A distinct protoderm was not observed in these roots, which had a large open meristem and a root cap with a well-defined columella. During nodulation, the meristem became reduced in size, and its constituent cells became vacuolate until all but a few resembled ground tissue. The root cap senesced during nodulation, and a recognizable root cap was absent from mature nodules. A file of densely cytoplasmic cells with centrally positioned nuclei developed in the nodule cortex. This layer was continuous across the nodule apex, and was identical to the presumptive algal-zone described previously by other authors. Light-induced nodules branched dichotomously and were identical to algal-free nodules described by other authors. In dichotomously branched nodules, each lobe was covered by a parenchymatous mantle analogous to a root cap. A unicellular layer similar to the presumptive algal zone spanned the gap between opposite nodule lobes, and extended beneath each lobe before terminating in the cortex. Typical meristematic regions were not observed in these nodules. Based on cell sizes and patterns, a meristematic zone was thought to exist between the mantle and the inner cortex.
American Journal of Botany © 1983 Botanical Society of America, Inc.