Abstract
Inbreeding depression is important in the evolution of plant populations and mating systems. Previous studies have suggested that early-acting inbreeding depression in plants is primarily due to lethal alleles and possibly epistatic interactions. Recent advances in molecular markers now make genetic mapping a powerful tool to study the genetic architecture of inbreeding depression. We describe a genome-wide evaluation of embryonic viability loci in a selfed family of loblolly pine (Pinus taeda L.), using data from AFLP markers from an essentially complete genome map. Locus positions and effects were estimated from segregation ratios using a maximum-likelihood interval mapping procedure. We identified 19 loci showing moderately deleterious to lethal embryonic effects. These loci account for >13 lethal equivalents, greater than the average of 8.5 lethal equivalents reported for loblolly pine. Viability alleles show predominantly recessive action, although potential overdominance occurs at 3 loci. We found no evidence for epistasis in the distribution of pairwise marker correlations or in the regression of fitness on the number of markers linked to deleterious alleles. The predominant role of semilethal alleles in embryonic inbreeding depression has implications for the evolution of isolated populations and for genetic conservation and breeding programs in conifers.
Full Text
The Full Text of this article is available as a PDF (168.2 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Fu Y. B., Ritland K. Marker-based inferences about epistasis for genes influencing inbreeding depression. Genetics. 1996 Sep;144(1):339–348. doi: 10.1093/genetics/144.1.339. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hedrick PW, Savolainen O, Karkkainen K. Factors influencing the extent of inbreeding depression: an example from scots pine . Heredity (Edinb) 1999 Apr;82(Pt 4):441–450. doi: 10.1038/sj.hdy.6885020. [DOI] [PubMed] [Google Scholar]
- Kao C. H., Zeng Z. B., Teasdale R. D. Multiple interval mapping for quantitative trait loci. Genetics. 1999 Jul;152(3):1203–1216. doi: 10.1093/genetics/152.3.1203. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lander E. S., Botstein D. Mapping mendelian factors underlying quantitative traits using RFLP linkage maps. Genetics. 1989 Jan;121(1):185–199. doi: 10.1093/genetics/121.1.185. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mitchell-Olds T. Interval mapping of viability loci causing heterosis in Arabidopsis. Genetics. 1995 Jul;140(3):1105–1109. doi: 10.1093/genetics/140.3.1105. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Morton N. E., Crow J. F., Muller H. J. AN ESTIMATE OF THE MUTATIONAL DAMAGE IN MAN FROM DATA ON CONSANGUINEOUS MARRIAGES. Proc Natl Acad Sci U S A. 1956 Nov;42(11):855–863. doi: 10.1073/pnas.42.11.855. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Remington D. L., Whetten R. W., Liu B. H., O'Malley D. M. Construction of an AFLP genetic map with nearly complete genome coverage in Pinus taeda. Theor Appl Genet. 1999 Jun;98(8):1279–1292. doi: 10.1007/s001220051194. [DOI] [PubMed] [Google Scholar]
- Rouppe van der Voort J. N., van Zandvoort P., van Eck H. J., Folkertsma R. T., Hutten R. C., Draaistra J., Gommers F. J., Jacobsen E., Helder J., Bakker J. Use of allele specificity of comigrating AFLP markers to align genetic maps from different potato genotypes. Mol Gen Genet. 1997 Jul;255(4):438–447. doi: 10.1007/s004380050516. [DOI] [PubMed] [Google Scholar]
- Stuber C. W., Lincoln S. E., Wolff D. W., Helentjaris T., Lander E. S. Identification of genetic factors contributing to heterosis in a hybrid from two elite maize inbred lines using molecular markers. Genetics. 1992 Nov;132(3):823–839. doi: 10.1093/genetics/132.3.823. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vos P., Hogers R., Bleeker M., Reijans M., van de Lee T., Hornes M., Frijters A., Pot J., Peleman J., Kuiper M. AFLP: a new technique for DNA fingerprinting. Nucleic Acids Res. 1995 Nov 11;23(21):4407–4414. doi: 10.1093/nar/23.21.4407. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zeng Z. B. Precision mapping of quantitative trait loci. Genetics. 1994 Apr;136(4):1457–1468. doi: 10.1093/genetics/136.4.1457. [DOI] [PMC free article] [PubMed] [Google Scholar]