Simulation of cyclic single cross selection
- 29 Downloads
Computer simulation was used to compare Hallauer's cyclic single cross selection (CSCS) with reciprocal recurrent selection (RRS). Three epistatic and three non-epistatic models with 60 loci determining a single character provided the genetic base. The rate of advance over seven cycles was always greater for CSCS than for RRS on either a cycle or generation basis. No genetic conditions were found where CSCS failed to respond. The advantages of CSCS increases as the proportion of non-additive genetic variance increases. Genetic advance of the hybrid population was shown to result from the joint effects of an average change in gene frequency and complementary effects (nicking) of selection. Nicking effects accounted for most of the advance for some starting conditions. RRS generally had higher selection limits with no epistasis or low gene frequency of the dominant allele. CSCS generally had higher limits with epistasis or high frequency of the dominant allele. We suggested that CSCS begin with divergent genetic populations and strong selection intensity for three cycles. Final selection of superior single crosses was indicated when the lines were completely inbred.
KeywordsGene Frequency Joint Effect Genetic Condition Average Change Dominant Allele
Unable to display preview. Download preview PDF.
- 1.Comstock, R. E., Robinson, H. F., Harvey, P. H.: A breeding procedure designed to make maximum use of both general and specific combining ability. Agron. J. 41, 360–367 (1949).Google Scholar
- 2.Cockerham, C. C.: Implications of genetic variances in a hybrid breeding program. Crop Sci. 1, 47–52 (1961).Google Scholar
- 3.Cress, C. E.: Reciprocal recurrent selection and modifications in simulated populations. Crop Sci. 7, 561–567 (1967).Google Scholar
- 4.Gill, J. L.: Effects of finite size on selection advance in simulated genetic populations. Aust. Jour, of Biological Sci. 18, 599–617 (1965).Google Scholar
- 5.Hallauer, A. R.: Development of single-cross hybrids from two-eared maize populations. Crop Sci. 7, 192–195 (1967a).Google Scholar
- 6.Hallauer, A. R.: Performance of single-cross hybrids from two-ear varieties. Ann. Hybrid Corn Industry Res. Conf. Proc. 22, 74–81 (1967b).Google Scholar
- 7.Harter, H. L.: Expected values of normal order statistics. Biometrika 48, 151–165 (1961).Google Scholar
- 8.Russell, W. A., Eberhart, S. A.: Effects of three gene loci in the inheritance of quantitative characters in maize. Crop Sci. 10, 165–169 (1970).Google Scholar
- 9.Sprague, G. F., Thomas, W. I.: Further evidence of epistasis in single and threeway cross yields of maize (Zea mays L.). Crop Sci. 7, 355–356 (1967).Google Scholar
- 10.Stuber, C. W., Moll, R. H.: Epistasis in maize (Zea mays L.). I. F1 hybrids and their S1 progeny. Crop Sci. 9, 124–127 (1969).Google Scholar