Issue |
Genet. Sel. Evol.
Volume 36, Number 3, May-June 2004
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Page(s) | 297 - 324 | |
DOI | https://doi.org/10.1051/gse:2004003 |
DOI: 10.1051/gse:2004003
Optimizing purebred selection for crossbred performance using QTL with different degrees of dominance
Jack C.M. Dekkers and Reena ChakrabortyDepartment of Animal Science, 225C Kildee Hall, Iowa State University, Ames, IA, 50011, USA
(Received 9 April 2003; accepted 17 December 2003)
Abstract
A method was developed to optimize simultaneous selection for a quantitative trait with a known QTL within a male and a female
line to maximize crossbred performance from a two-way cross. Strategies to maximize cumulative discounted response in crossbred
performance over ten generations were derived by optimizing weights in an index of a QTL and phenotype. Strategies were compared
to selection on purebred phenotype. Extra responses were limited for QTL with additive and partial dominance effects, but
substantial for QTL with over-dominance, for which optimal QTL selection resulted in differential selection in male and female
lines to increase the frequency of heterozygotes and polygenic responses. For over-dominant QTL, maximization of crossbred
performance one generation at a time resulted in similar responses as optimization across all generations and simultaneous
optimal selection in a male and female line resulted in greater response than optimal selection within a single line without
crossbreeding. Results show that strategic use of information on over-dominant QTL can enhance crossbred performance without
crossbred testing.
Key words: crossbreeding / selection / quantitative trait loci / marker assisted selection
Correspondence and reprints: jdekkers@iastate.edu
© INRA, EDP Sciences 2004