Abstract
The standard approaches to estimation of quantitative genetic parameters and prediction of response to selection on quantitative traits are based on theory derived for populations undergoing random mating. Many studies demonstrate, however, that mating systems in natural populations often involve inbreeding in various degrees (i.e. , self matings and matings between relatives). Here we apply theory developed for estimating quantitative genetic parameters for partially inbreeding populations to a population of Nemophila menziesii recently obtained from nature and experimentally inbred. Two measures of overall plant size and two of floral size expressed highly significant inbreeding depression. Of three dominance components of phenotypic variance that are defined under partial inbreeding, one was found to contribute significantly to phenotypic variance in flower size and flowering time, while the remaining two components contributed only negligibly to variation in each of the five traits considered. Computer simulations investigating selection response under the more complete genetic model for populations undergoing mixed mating indicate that, for parameter values estimated in this study, selection response can be substantially slowed relative to predictions for a random mating population. Moreover, inbreeding depression alone does not generally account for the reduction in selection response.
Full Text
The Full Text of this article is available as a PDF (152.7 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Ballou J. D. Ancestral inbreeding only minimally affects inbreeding depression in mammalian populations. J Hered. 1997 May-Jun;88(3):169–178. doi: 10.1093/oxfordjournals.jhered.a023085. [DOI] [PubMed] [Google Scholar]
- COMSTOCK R. E., ROBINSON H. F. The components of genetic variance in populations of biparental progenies and their use in estimating the average degree of dominance. Biometrics. 1948 Dec;4(4):254–266. [PubMed] [Google Scholar]
- Cockerham C. C. Higher order probability functions of identity of allelles by descent. Genetics. 1971 Oct;69(2):235–246. doi: 10.1093/genetics/69.2.235. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cockerham C. C., Weir B. S. Covariances of relatives stemming from a population undergoing mixed self and random mating. Biometrics. 1984 Mar;40(1):157–164. [PubMed] [Google Scholar]
- Latter B. D., Mulley J. C., Reid D., Pascoe L. Reduced genetic load revealed by slow inbreeding in Drosophila melanogaster. Genetics. 1995 Jan;139(1):287–297. doi: 10.1093/genetics/139.1.287. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Santiago E., Caballero A. Effective size of populations under selection. Genetics. 1995 Feb;139(2):1013–1030. doi: 10.1093/genetics/139.2.1013. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schultz S. T., Willis J. H. Individual variation in inbreeding depression: the roles of inbreeding history and mutation. Genetics. 1995 Nov;141(3):1209–1223. doi: 10.1093/genetics/141.3.1209. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shaw R. G., Platenkamp G. A., Shaw F. H., Podolsky R. H. Quantitative genetics of response to competitors in Nemophila menziesii: a field experiment. Genetics. 1995 Jan;139(1):397–406. doi: 10.1093/genetics/139.1.397. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wei M., Caballero A., Hill W. G. Selection response in finite populations. Genetics. 1996 Dec;144(4):1961–1974. doi: 10.1093/genetics/144.4.1961. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wray N. R., Thompson R. Prediction of rates of inbreeding in selected populations. Genet Res. 1990 Feb;55(1):41–54. doi: 10.1017/s0016672300025180. [DOI] [PubMed] [Google Scholar]
- Wright A. J., Cockerham C. C. Selection with partial selfing. I. Mass selection. Genetics. 1985 Mar;109(3):585–597. doi: 10.1093/genetics/109.3.585. [DOI] [PMC free article] [PubMed] [Google Scholar]