Hostname: page-component-8448b6f56d-tj2md Total loading time: 0 Render date: 2024-04-16T17:59:06.877Z Has data issue: false hasContentIssue false

Diallel analysis of competition between diploid and tetraploid genotypes of Secale cereale grown at two densities

Published online by Cambridge University Press:  27 March 2009

J. Norrington-Davies
Affiliation:
Department of Agricultural Botany, University College of WalesAberystwyth.
Janice M. Hutto
Affiliation:
Department of Agricultural Botany, University College of WalesAberystwyth.

Summary

Two inbred diploid lines of Secale cereale L. and their derived tetraploids were grown together with a commercial diploid and tetraploid in all possible pair combinations in a pot experiment. Comparisons between lines and varieties were made in respect to dry weight measured at 30 weeks.

The competitive effects within mixtures were not compensatory, the commercial varieties tending to increase in dry weight more than the homozygous inbred lines decreased. This gave rise to mixture means which tended to exceed their mid-constituent values.

The analysis of reciprocal differences in dry weight showed that the effects of competition between any one genotype and its associate in mixtures were constant (alpha competition), the sign and magnitude of the alpha effect being related to the pure stand values of the genotype.

The mean effect of competition was to increase the difference in dry weight between genotypes by 2·108 g for each gram by which the genotypes differed when grown alone. In each case the values for genotypes with the higher dry weight increased in mixture whereas the values for those with lower dry weights decreased.

Not surprisingly, the commercial varieties were found to be better competitors than the inbred lines, but of more interest was the ineffectiveness of chromosome doubling on competitive ability. Under the conditions of density and fertility reported here, the tetraploid inbred lines could not be distinguished from their diploid progenitors either in their competitive ability or in their reaction to increased density when grown in mixtures. The same is true for the tetraploid and diploid commercial varieties.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1972

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Durrant, A. (1965). Analysis of reciprocal differences in diallel crosses. Heredity, Lond. 20, 573607.CrossRefGoogle Scholar
Hazabika, M. H. & Rees, H. (1967). Genobypic control of chromosome behaviour in rye. X. Chromosome pairing and fertility in autotetraploids. Heredity, Lond. 22, 317–32.Google Scholar
McGilchrist, C. A. (1965). Analysis of competition experiments. Biometrics 21, 975–85.CrossRefGoogle Scholar
Norrington-Davies, J. (1967). Application of diallel analysis to experiments in plant competition. Euphylica 16, 391406.Google Scholar
Norrington-Davies, J. (1968). Diallel analysis of competition between grass species. J. agric. Sci., Camb. 71, 223–31.Google Scholar
Rees, H. (1955). Genotypic control of chromosome behaviour in rye. I. Inbred lines. Heredity, Lond. 9, 93116.CrossRefGoogle Scholar
Stebbins, G. L. (1950). Variation and Evolution in Plants, pp. 301–8. New York: Columbia University Press.CrossRefGoogle Scholar
Williams, E. J. (1962). The analysis of competition experiments. Aust. J. biol. Sci. 15, 509—25.Google Scholar