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Two-way selection for body weight in Tribolium on two levels of nutrition*

Published online by Cambridge University Press:  14 April 2009

R. T. Hardin
Affiliation:
Population Genetics Institute, Purdue University, Lafayette, Indiana
A. E. Bell
Affiliation:
Population Genetics Institute, Purdue University, Lafayette, Indiana
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Parameters necessary for predicting direct and correlated responses for large and small 13-day larval weight in T. castaneum on two levels of nutrition were estimated in the base population. Larval weight in the GOOD environment was approximately twice that observed in POOR. Heritabilities (estimated from the ratio of sire component to total phenotype variance) of larval weight on the two rations were similar, 0·21 ± 0·06 and 0·19 ± 0·05 for GOOD and POOR, respectively. Heritabilities based on dam-offspring covariances were similar to these, but those obtained from full-sib covariances were much larger (0·97 ± 0·07 for GOOD and 0·69 ± 0·07 for POOR). This suggested that considerable dominance rather than maternal effects were present. The genetic correlation between growth on GOOD and growth on POOR was estimated as + 0·60 ± 0·21.

The selection experiment was replicated four times with each replication extending over eight generations. Good agreement between predicted and observed values for direct selection was observed for large selection in both environments and small selection in POOR. However, response to small selection in GOOD was significantly greater than predicted in all four replications and was associated with increased selection differentials. Realized heritabilities were approximately the same for both directions in GOOD yet asymmetrical responses occurred for all replications due to unequal selection differentials. On the other hand, realized heritabilities were asymmetrical in POOR. Those observed for small selection were more than twice the size of those calculated for large lines. However, the responses in POOR were symmetrical since the selection differentials varied inversely with the realized heritabilities.

Because of the asymmetry observed for heritabilities and selection differentials, correlated responses were poorly predicted. The average effective genetic correlation between growth in GOOD and growth in the POOR environment agreed remarkably well with the base estimate, yet asymmetry of the genetic correlation was a consistent phenomenon with values for the large lines being less than the base parameter while small lines were uniformly larger.

Asymmetries of the various genetic parameters were not anticipated from base estimates. They were not caused by sampling or chance fluctuations since all four replications were remarkably consistent. Asymmetry for any one genetic parameter (e.g. heritability) was associated with a particular environment or direction of selection while other genetic parameters reacted asymmetrically in populations exposed to a different set of environmental treatments.

For maximum performance in a single environment, these results show that selection should be practiced in that environment. With regard to mean performance in GOOD and POOR environments, selection for large size in POOR gave some 25% more gain than selection in GOOD. Selection for small size in either environment was equally effective in obtaining minimum size in both environments.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1967

References

REFERENCES

Abflanalp, H., Ogasawara, F. X. & Asmundson, V. S. (1963). Influence of selection for body weight at different ages on growth of turkeys. Br. Poult. Sci. 4, 7182.CrossRefGoogle Scholar
Bartlett, M. S. & Kendall, D. G. (1946). The statistical analysis of variance-heterogenic and log transformation. Jl. R. Statist. Soc., Ser. B, 8, 128138.Google Scholar
Becker, W. A. & Berg, L. R. (1959). Effect of growth rate, homozygosity and heterozygosity of chickens on the sensitivity of experiments. Poult. Sci. 38, 14091422.CrossRefGoogle Scholar
Bell, A. E. & McNary, H. W. (1963). Genetic correlation and asymmetry of the correlated response from selection for increased body weight of Tribolium in two environments. Proc. XI Int. Congr. Genet. p. 256.Google Scholar
Bohren, B. B., Hill, W. G. & Robertson, A. (1966). Some observations on asymmetrical correlated responses to selection. Genet. Res. 7, 4457.CrossRefGoogle ScholarPubMed
Clarke, J. M., Smith, J. Maynard & Sondhi, K. C. (1961). Asymmetrical response to selection for rate of development in Drosophila aubobscura. Genet. Res. 2, 7081.CrossRefGoogle Scholar
Dickerson, G. E. (1962). Implications of genetic environmental interactions in animal breeding. Anim. Prod. 4, 4764.Google Scholar
Englert, DuWayne C. & Bell, A. E. (1963). Genetic differences in the growth curve of Tribolium castaneum. Growth, 27, 8799.Google Scholar
Falconer, D. S. (1952). The problem of environment and selection. Am. Nat. 86, 293298.CrossRefGoogle Scholar
Falconer, D. S. (1953). Asymmetrical response in selection experiments. I.U.B.S. Symposium on Genetics of Population Structure, Pavia, pp. 1641.Google Scholar
Falconer, D. S. (1960). Selection of mice for growth on high and low planes of nutrition. Genet. Res. 1, 91113.CrossRefGoogle Scholar
Falconer, D. S. & Latyszewski, M. (1952). The environment in relation to selection for size in mice. J. Genet. 51, 6780.CrossRefGoogle Scholar
Fowler, S. H. & Ensminger, M. E. (1960). Interactions between genotype and plane of nutrition in selection for rate of gain in swine. J. Anim. Sci. 19, 434449.CrossRefGoogle Scholar
Hammond, J. (1947). Animal breeding in relation to nutrition and environmental conditions. Biol. Rev. 22, 195213.CrossRefGoogle ScholarPubMed
Hardin, R. T., Rogler, J. C. & Bell, A. E. (1966). Genetic and environmental interactions in growth of Tribolium castaneum. Can. J. Zool. (in press).Google Scholar
Hazel, L. N., Baker, M. L. & Reinmiller, C. F. (1943). Genetic and environmental correlations between the growth rates of pigs at different ages. J. Anim. Sci. 2, 118128.CrossRefGoogle Scholar
James, J. W. (1961). Selection in two environments. Heredity, Lond. 16, 145152.CrossRefGoogle Scholar
Korkman, N. (1961). Selection for size in mice in different nutritional environments. Hereditas, 47, 342356.CrossRefGoogle Scholar
Lerner, I. M. (1950). Population Genetics and Animal Improvement. Cambridge: University Press.Google Scholar
Lerner, I. M. (1958). The Genetic Basis of Selection. New York: John Wiley & Sons.Google Scholar
Lush, J. L. (1948). The Genetics of Populations (mineographed notes). Iowa State University.Google Scholar
McBride, Glenorchy (1958). The environment and animal breeding problems. Anim. Breed. Abstr. 26, 349358.Google Scholar
McLaren, A. & Michie, D. (1956). Variability of response in experimental animals. A comparison of the reactions of inbred, F1 hybrid and random bred mice to a narcotic drug. J. Genet. 54, 440455.CrossRefGoogle Scholar
McNary, H. W. & Bell, A. E. (1962). The effect of environment on response to selection for body weight in Tribolium castaneum. Genetics, 47, 969970.Google Scholar
Robertson, A. (1959). The sampling variance of the genetic correlation coefficient. Biometrics, 15, 469485.CrossRefGoogle Scholar
Yamada, Yukio (1962). Genotype by environment interaction and genetic correlation of the same trait under different environments. Jap. J. Genet. 37, 498509.CrossRefGoogle Scholar