Present address: Patuxent Wildlife Research Center, U.S. Geological Survey, 11510 American Holly Drive, Laurel, MD 20708, USA.
Demographic consequences of inbreeding and outbreeding in Arnica montana: a field experiment
Article first published online: 7 AUG 2002
Journal of Ecology
Volume 90, Issue 4, pages 593–603, August 2002
How to Cite
Luijten, S. H., Kéry, M., Oostermeijer, J. G. B. and Den Nijs, H. C. M. (2002), Demographic consequences of inbreeding and outbreeding in Arnica montana: a field experiment. Journal of Ecology, 90: 593–603. doi: 10.1046/j.1365-2745.2002.00703.x
- Issue published online: 7 AUG 2002
- Article first published online: 7 AUG 2002
- Received 19 April 2001 revision accepted 4 February 2002
- mate availability;
- offspring fitness;
- 1The genetic constitution of populations may significantly affect demography. Founder populations or isolated remnants may show inbreeding depression, while established populations can be strongly adapted to the local environment. Gene exchange between populations can lead to better performance if heterozygosity levels are restored (heterosis), or to reduced performance if coadapted gene complexes are disrupted (outbreeding depression).
- 2Five populations of the self-incompatible perennial Arnica montana (Asteraceae) were analysed for the demographic consequences of inbreeding and of intra- and interpopulation outcrossing, using both small and large populations as donors for the latter. We analysed seed production and seed weight and monitored growth, survival and flowering of offspring introduced as seeds and as 4-week-old seedlings in a 4-year field experiment.
- 3Reduced seed set after selfing was probably due to the self-incompatibility system rather than to inbreeding depression. There was a significant increase for seed set after interpopulation crosses, which resulted from the alleviation of low mate availability in one of the small populations.
- 4Significant inbreeding depression was observed for growth rates of plants introduced as seedlings. We found significant heterosis for flowering probability of plants introduced as seeds, but for plants introduced as seedlings, heterosis for seedling size and flowering probability was only marginally significant. Outbreeding depression was not observed.
- 5The results of this study are important for reinforcement measures in small, remnant populations. Significant differences among populations for all measured fitness components suggest that reinforcement is best achieved using material from several populations.
- 6The observed higher survival of seedlings as compared with seeds suggests that it is better to plant individuals than to sow. Sowing, however, is easier and cheaper, and was more likely to eliminate poorly adapted genotypes before they contribute to the next generation.