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.

Studies in Potentilla L. I. Embryological Investigations into the Mechanism of Agamospermy in British P. Tabernaemontani Aschers

Gordon L. Smith
The New Phytologist
Vol. 62, No. 3 (Oct., 1963), pp. 264-282
Published by: Wiley on behalf of the New Phytologist Trust
Stable URL: http://www.jstor.org/stable/2429836
Page Count: 20
  • Read Online (Free)
  • 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.
Studies in Potentilla L. I. Embryological Investigations into the Mechanism of Agamospermy in British P. Tabernaemontani Aschers
Preview not available

Abstract

The mechanism of reproduction by seed in five British topodemes of Potentilla tabernaemontani has been investigated by means of crossing experiments and embryologically. With a variety of Potentilla species as pollen plants, crossing experiments yield progenies which, except for the occasional aberrant, are uniform and resemble the female parent in morphology. Embryological preparations show meiosis to be suppressed in all topodemes. In all except one topodeme, the majority of unreduced embryo-sacs are diplosporous in origin, in the other they are predominantly aposporous. Although the egg-cell is capable of autonomous parthenogenetic development, functional seed is never formed without previous pollination. The conclusion to be drawn from embryology and crossing experiments is therefore that the seed produced is almost completely pseudogamous, thereby reproducing faithfully the genotype of the parent. The topodeme from Fleam Dyke, Cambridge, differed from the others investigated in a number of important respects. These included chromosome number, male sterility, the origin of unreduced embryosacs and the precocious development of parthenogenetic embryos.

Page Thumbnails

  • Thumbnail: Page 
264
    264
  • Thumbnail: Page 
265
    265
  • Thumbnail: Page 
266
    266
  • Thumbnail: Page 
267
    267
  • Thumbnail: Page 
268
    268
  • Thumbnail: Page 
269
    269
  • Thumbnail: Page 
270
    270
  • Thumbnail: Page 
271
    271
  • Thumbnail: Page 
272
    272
  • Thumbnail: Page 
273
    273
  • Thumbnail: Page 
274
    274
  • Thumbnail: Page 
275
    275
  • Thumbnail: Page 
276
    276
  • Thumbnail: Page 
277
    277
  • Thumbnail: Page 
278
    278
  • Thumbnail: Page 
279
    279
  • Thumbnail: Page 
280
    280
  • Thumbnail: Page 
281
    281
  • Thumbnail: Page 
282
    282
  • Thumbnail: Page 
[unnumbered]
    [unnumbered]