Present address: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
Sex-specific fitness variation in gynodioecious Beta vulgaris ssp. maritima: do empirical observations fit theoretical predictions?
Article first published online: 28 SEP 2011
© 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology
Journal of Evolutionary Biology
Volume 24, Issue 11, pages 2456–2472, November 2011
How to Cite
DE CAUWER, I., ARNAUD, J.-F., COURSEAUX, A. and DUFAY, M. (2011), Sex-specific fitness variation in gynodioecious Beta vulgaris ssp. maritima: do empirical observations fit theoretical predictions?. Journal of Evolutionary Biology, 24: 2456–2472. doi: 10.1111/j.1420-9101.2011.02380.x
- Issue published online: 12 OCT 2011
- Article first published online: 28 SEP 2011
- Received 24 March 2011; revised 22 July 2011; accepted 24 July 2011
- cytoplasmic male sterility;
- female advantage;
- restoration of male fertility;
- sexual polymorphisms
In gynodioecious species, in which hermaphroditic and female plants co-occur, the maintenance of sexual polymorphism relies on the genetic determination of sex and on the relative fitness of the different phenotypes. Flower production, components of male fitness (pollen quantity and pollen quality) and female fitness (fruit and seed set) were measured in gynodioecious Beta vulgaris spp. maritima, in which sex is determined by interactions between cytoplasmic male sterility (CMS) genes and nuclear restorers of male fertility. The results suggested that (i) female had a marginal advantage over hermaphrodites in terms of flower production only, (ii) restored CMS hermaphrodites (carrying both CMS genes and nuclear restorers) suffered a slight decrease in fruit production compared to non-CMS hermaphrodites and (iii) restored CMS hermaphrodites were poor pollen producers compared to non-CMS hermaphrodites, probably as a consequence of complex determination of restoration. These observations potentially have important consequences for the conditions of maintenance of sexual polymorphism in B. vulgaris and are discussed in the light of existing theory on evolutionary dynamics of gynodioecy.