uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
The ecological significance of cleistogamy
Uppsala University, Department of Ecological Botany.
1998 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Various aspects of cleistogamy, a reproductive system combining selfing in closed (cleistogamous) flowers and potential outcrossing in open (chasmogamous) flowers, were investigated in four perennial species. The main purpose was to shed some light on the adaptive value of having a dual reproductive strategy, and to test some hypotheses on the maintenance of xenogamy. In field studies including variation between years and sites, chasmogamous (CH) and cleistogamous (CL) flower and seed production were quantified in ramets of different size. Performance of CH and CL offspring under different conditions was examined in comparative field and garden studies, and an experiment on ballistic dispersal of CH and CL seeds was conducted.

It was found that in Oxalis acetosella and Viola hirta, CL production is influenced by ramet size and reproductive success in the CH phase. Production in both phases varies considerably among years and sites in O. acetosella, and on the whole reproductive success is not greater in the CL phase than in the CH phase. In addition, the two phases seem to have their optima at different points along temporal and spatial variation scales in O. acetosella.

In O. acetosella, Viola mirabilis, and V. riviniana, germination was found to be lower in CL seeds than in CH seeds, and in V. hirta and V. rivinana CL offspring were on average smaller than CH offspring. These differences may be attributable to inbreeding depression in selfed offspring, but regarding seedling survivorship there is no difference between the two offspring types. In the dispersal experiment CL seeds of O. acetosella were thrown farther from the mother plant than were CH seeds, in contrast to data from other species.

The results of this study partly contradict the traditional view on cleistogamy and the relationship between xenogamy and autogamy, where perhaps the genetic aspects have been overrated. The main selective value of a dual reproductive system is probably in optimizing individual seed output by compensating for environmental stochasticity.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis , 1998. , 31 p.
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-232X ; 412
Keyword [en]
Ecology, bet-hedging, chasmogamous, enviromnental variation, fitness, outcrossing, progeny, selling
Keyword [sv]
National Category
Research subject
Ecological Botany
URN: urn:nbn:se:uu:diva-265ISBN: 91-554-4350-8OAI: oai:DiVA.org:uu-265DiVA: diva2:161989
Public defence
1999-01-22, lecture room at the Dep. of Ecological Botany, Uppsala, Uppsala, 10:00
Available from: 1999-01-01 Created: 1999-01-01Bibliographically approved

Open Access in DiVA

No full text
Buy this publication >>

By organisation
Department of Ecological Botany

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 368 hits
ReferencesLink to record
Permanent link

Direct link