Effects of two-locus linkage disequilibrium on progress from reciprocal recurrent selection in maize
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Summary
Because each population in a reciprocal recurrent selection program can be dually described as a tester for its reciprocal and as a population subject to selection, selection progress can be partitioned into algebraic terms that are (a) unaffected by initial linkage disequilibrium, (b) modified exclusively by initial linkage disequilibrium in the selection populations, (c) influenced solely by initial linkage disequilibrium in the tester populations, and (d) modulated jointly by initial linkage disequilibrium in both populations. If only additive genetic effects are present in the intercross population, linkage disequilibrium affects selection progress via only the selection populations. Initial linkage disequilibrium affects selection progress via the tester populations, and/or the selection and tester populations jointly, only in the presence of epistatic effects for which, out of all alleles involved in the interaction, two alleles emanate from the tester population. If only additive x additive epistasis is present, initial linkage disequilibrium affects progress via both the selection and tester populations, but the effect is permanent via only the selection populations. The effect of initial linkage disequilibrium via the tester populations, and/or the selection and tester populations jointly, is permanent only in the presence of additive x dominance and/or dominance x dominance epistasis in the intercross population.
Key words
Corn Zea mays L. Linkage Reciprocal recurrent selection RecombinationPreview
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Literature
- Comstock, R.E.; Robinson, H.F.; Harvey, P.H. (1949): A breeding procedure designed to make maximum use of both general and specific combining ability. Agron. J. 41, 360–367Google Scholar
- Griffing, B. (1962): Prediction formulae for general combining ability selection methods utilizing one or two random-mating populations. Aust. J. Biol. Sci. 15, 650–665Google Scholar
- Hallauer, A.R.; Miranda, Fo., J.B. (1981): Quantitative genetics in maize breeding. Ames: Iowa State University PressGoogle Scholar
- Johnson, G.R. (1982): Two-locus theory in recurrent selection for general combining ability in maize. Theor. Appl. Genet. 61, 279–283Google Scholar
- Schnell, F.W. (1961): Some general formulations of linkage effects in inbreeding. Genetics 46, 947–957Google Scholar
- Stuber, C.W.; Cockerham, C. Clark, (1966): Gene effects and variances in hybrid populations. Genetics 54, 1279–1286Google Scholar
- Weir, B.S.; Cockerham, C. Clark, (1977): Two-locus theory in quantitative genetics. In: Proc. Int. Conf. Quant. Gen. (eds. Kempthorne, O.; Pollack, E.; Bailey, T.B., Jr.), pp. 247–269. Ames: Iowa State University PressGoogle Scholar