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.

ARE RELATIONSHIPS BETWEEN POLLEN-OVULE RATIO AND POLLEN AND SEED SIZE EXPLAINED BY SEX ALLOCATION?

Martin Burd
Evolution
Vol. 65, No. 10 (OCTOBER 2011), pp. 3002-3005
Stable URL: http://www.jstor.org/stable/41240884
Page Count: 4
  • Read Online (Free)
  • Download ($4.00)
  • 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.
ARE RELATIONSHIPS BETWEEN POLLEN-OVULE RATIO AND POLLEN AND SEED SIZE EXPLAINED BY SEX ALLOCATION?
Preview not available

Abstract

Positive correlations between pollen-ovule ratio and seed size, and negative correlations between pollen-ovule ratio and pollen grain size have been noted frequently in a wide variety of angiosperm taxa. These relationships are commonly explained as a consequence of sex allocation on the basis of a simple model proposed by Charnov. Indeed, the theoretical expectation from the model has been the basis for interest in the empirical pattern. However, the predicted relationship is a necessary consequence of the mathematics of the model, which therefore has little explanatory power, even though its predictions are consistent with empirical results. The evolution of pollen-ovule ratios is likely to depend on selective factors affecting mating system, pollen presentation and dispensing, patterns of pollen receipt, pollen tube competition, female mate choice through embryo abortion, as well as genetic covariances among pollen, ovule, and seed size and other reproductive traits. To the extent the empirical correlations involving pollen-ovule ratios are interesting, they will need explanation in terms of a suite of selective factors. They are not explained simply by sex allocation trade-offs.

Page Thumbnails

  • Thumbnail: Page 
3002
    3002
  • Thumbnail: Page 
3003
    3003
  • Thumbnail: Page 
3004
    3004
  • Thumbnail: Page 
3005
    3005