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.

The Relationship of Plant Size to Self-Pollination in Mertensia Ciliata

Monica A. Gerber
Ecology
Vol. 66, No. 3 (Jun., 1985), pp. 762-772
Published by: Wiley
DOI: 10.2307/1940537
Stable URL: http://www.jstor.org/stable/1940537
Page Count: 11
  • Download ($42.00)
  • Subscribe ($19.50)
  • Cite this Item
The Relationship of Plant Size to Self-Pollination in Mertensia Ciliata
Preview not available

Abstract

This study tested the hypothesis that self-pollination and, as a result, inbreeding rate increased with plant size in Mertensia ciliata, a self-compatible, profusely flowering perennial. The hypothesis is based on two subsidiary hypotheses, which were examined: (1) the dispersal of pollen among flowers and among plants is generally limited in plant populations; and (2) individual pollinators are likely to make longer visits to large than to small plants, and to spread higher proportions of self pollen rather than foreign pollen among flowers of large plants. Because M. ciliata exhibits inbreeding depression in seed-set and seed mass, increased self-pollination and inbreeding would lower the reproductive output of flowers on large plants. However, in experiments with bumble bees confined to nylon mesh cages, I found that the carry-over of pollen between flowers by bees is extensive in M. ciliata. In addition, individual bees visit only a few more flowers per visit to large than to small plants, and large plants attract more bees per minutes than small plants. Using these data, I constructed a mathematical model to estimate the amount of foreign pollen a flower should receive as a function of plant size. The model predicts that flowers on all plants should receive approximately equal amounts of foreign pollen, and that self-pollination and hence inbreeding will not vary with plant size. These predictions were supported by direct measures of flowers in the field: no differences were found in foreign pollen receipt and in reproductive output (seed-set and seed mass) between flowers from large and small plants.

Page Thumbnails

  • Thumbnail: Page 
762
    762
  • Thumbnail: Page 
763
    763
  • Thumbnail: Page 
764
    764
  • Thumbnail: Page 
765
    765
  • Thumbnail: Page 
766
    766
  • Thumbnail: Page 
767
    767
  • Thumbnail: Page 
768
    768
  • Thumbnail: Page 
769
    769
  • Thumbnail: Page 
770
    770
  • Thumbnail: Page 
771
    771
  • Thumbnail: Page 
772
    772