Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This 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.

Division of the Generative Cell and Late Development in the Male Gametophyte of Ginkgo biloba

William E. Friedman and Ernest M. Gifford
American Journal of Botany
Vol. 75, No. 9 (Sep., 1988), pp. 1434-1442
Stable URL: http://www.jstor.org/stable/2444465
Page Count: 9
  • Read Online (Free)
  • Download ($12.00)
  • Subscribe ($19.50)
  • Cite this Item
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

Abstract

Division of the generative cell in the male gametophyte of Ginkgo biloba to yield the sterile cell and spermatogenous cell was examined in vivo and in vitro. Evidence is presented in support of a new interpretation of development in which the sterile cell and spermatogenous cell arise from an unusual anticlinal ringlike division of the generative cell. This type of cell division is only known to occur during antheridial development in leptosporangiate ferns and stomatal development among certain ferns in the Schizaeaceae and Polypodiaceae. The strong similarities in development and cell arrangement within the male gametophytes of cycads and Ginkgo suggest that division of the generative cell in cycads may be the same as in Ginkgo. Although the ringlike (conically annular) divisions in the antheridia of leptosporangiate ferns and the male gametophytes of Ginkgo (and probably cycads) are remarkably similar and result in the production of a central spermatogenous cell, it is conjectural as to whether these patterns represent a striking convergence or evolutionary homology.

Page Thumbnails

  • Thumbnail: Page 
1434
    1434
  • Thumbnail: Page 
1435
    1435
  • Thumbnail: Page 
1436
    1436
  • Thumbnail: Page 
1437
    1437
  • Thumbnail: Page 
1438
    1438
  • Thumbnail: Page 
1439
    1439
  • Thumbnail: Page 
1440
    1440
  • Thumbnail: Page 
1441
    1441
  • Thumbnail: Page 
1442
    1442