Summary
A model to study genetic effects at the level of a population of testcross progenies is presented. As there is no dominance for the testcross value, with the restriction of epistasis to pairs of loci, only additive x additive epistasis can contribute to the variance among progenies. To estimate the variance among progenies due to epistasis, it is necessary to have the population structured in families of full sibs, half sibs or S1, with only a few plants per family tested in combination with the tester. Using a two-way mating design to produce the families, it is possible to estimate the variance due to additive x additive epistasis. The consequence of the presence of epistasis is studied at the level of recurrent selection for combining ability with the tester. It seems that epistasis itself does not change the efficiency of the breeding methods considered. However, when the population from intercrossing is structured in families, it could be efficient to use a combined selection when the heritability is very low. In this case it would be efficient to produce full-sib families (by single-pair matings) at the level of intercrossing. The best procedure is to produce such families at the same time as crossing with the tester. In comparison to the classical scheme of selection for combining ability with a tester, such a modification increases the efficiency of selection 41.1% if an off-season generation can be used.
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References
Chi RK, Eberhart SA, Penny LH (1969) Covariances among relatives in a maize variety. Genetics 63:511–520
Choo TM (1981) Doubled haploid for studying the inheritance of quantitative characters. Genetics 99:525–540
Choo TM, Kotecha A, Reinbergs E, Song LSP, Fejer SO (1986) Diallel analysis of grain yield in barley using doubled haploid lines. Plant Breed 97:129–137
Cockerham CC (1970) Avoidance and rate of inbreeding. In Kojima K (ed) Mathematical topics in population genetics. Springer, New York, pp 104–127
Gallais A (1979a) Is Fisher's model necessary for the theory of population improvement? Theor Appl Genet 58:117–180
Gallais A (1979b) Application du concept de valeur variétale à la théorie de la sélection de variétés hybrides. Ann Amel Plant 29:23–41
Gallais A (1989) Optimization of recurrent selection on the phenotypic value of doubled haploid lines. Theor Appl Genet 79: 501–504
Gallais A (1990) The quantitative genetics of doubled haploid populations. Application to selection for line value. Genetics 77: 501–504
Griffing B (1956) Concept of general and specific combining ability in relation to diallel crossing systems. Aust J Biol Sci 9:463–493
Griffing B (1962) Prediction formulae for general combining ability selection methods utilizing one or two random-mating populations. Aust J Biol Sci 15:650–665
Hallauer AR, Miranda JB (1981) Quantitative genetics in maize breeding. Iowa State University Press, Ames, 468 pp
Kempthorne O (1957) Introduction to quantitative genetics. Wiley and Sons, New York
Kimura M, Crow JF (1963) On the maximum avoidance of inbreeding. Genet Res Camb, pp 399–415
Lush JG (1943) Family merit and individual merit as bases for selection. Part I Am Nat 81:241–261. Part II Am Nat 81:362–379
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Communicated by A. R. Hallauer
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Gallais, A. A general approach for the study of a population of testcross progenies and consequences for recurrent selection. Theoret. Appl. Genetics 81, 493–503 (1991). https://doi.org/10.1007/BF00219439
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DOI: https://doi.org/10.1007/BF00219439