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Methods of analysing competition with special reference to herbage plants: II. Effects of associate plants

Published online by Cambridge University Press:  27 March 2009

J. Hill
J. Hill
Affiliation:
Welsh Plant Breeding Station, Aberystwyth
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Summary

An examination of the role played by associate plants in conditioning the behaviour of a competitor was carried out on a diallel arrangement of five perennial ryegrasa genotypes using regression techniques similar to those devised for the analysis of genotype-environment interactions. By far the largest proportion of the significant genotype x associate interaction could be ascribed to differences between the slopes of the fitted regression lines, with the three long-leaved genotypes (A, C and E)having the highest slopes and hence being the most sensitive to changes in the associate environment. Significant departures from the fitted regression lines occurred, however, but these could be traced solely to genotype C.

Theoretical models capable of identifying those conditions under which 50:50 mixtures may be expected, first, to exceed the average of their component monocultures, and secondly, to surpass the better monoculture, were developed. Applying these models to the present experiment confirms that the performance of the 50:50 mixtures generally exceeds the monoculture average, but rarely surpasses the better monoculture.

The scope of the regression technique was broadened to incorporate the 75:25 and 25: 75 mixtures, thereby revealing that the response of the two strongest competitors (C and E) is frequency dependent. Density dependent effects were also uncovered in this material, with genotype C the strongest competitor, being particularly noteworthy in this respect. The role of this regression technique in the development of new and highly productive mixtures is briefly discussed.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 81 , Issue 1 , August 1973 , pp. 91 - 98
Copyright
Copyright © Cambridge University Press 1973

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References

Breese, E. L. (1969). The measurement and significance of genotype-environment interactions in grasses. Heredity 24, 27–44.CrossRefGoogle Scholar
Breese, E. L. & Hill, J. (1973). Regression analysis of interactions between competing species. Heredity (in the Press).CrossRefGoogle Scholar
Bucio-Alanis, L. (1966). Environmental and genotype environmental components of variability. I. Inbred lines. Heredity 21, 387–97.CrossRefGoogle Scholar
Bucio-Alanis, L. & Hill, J. (1966). Environmental and genotype-environmental components of variability. II. Heterozygotes. Heredity 21, 399–405.CrossRefGoogle Scholar
Clements, F. E., Weaver, J. E. & Hanson, H. C. (1929). Plant competition. An analysis of community functions. Carnegie Inst. Wash. Publ. No. 398.Google Scholar
Finlay, K. W. & Wilkinson, G. N. (1963). The analysis of adaptation in a plant-breeding programme. Aust. J. agric. Res. 14, 742–54.CrossRefGoogle Scholar
Freeman, G. H. & Perkins, Jean M. (1971). Environmental and genotype-environmental components of variability. VIII. Relations between genotypes grown in different environments and measures of these environments. Heredity 27, 15–23.CrossRefGoogle Scholar
Fripp, Yvonne J. & Caten, C. E. (1971). Genotypeenvironmental interactions in Schizophyllum commune. I. Analysis and character. Heredity 27, 393–407.CrossRefGoogle ScholarPubMed
Hardwick, R. C. & Wood, J. T. (1972). Regression methods for studying genotype-environment interactions. Heredity 28, 209–22.CrossRefGoogle ScholarPubMed
Hill, J. & Shimamoto, Y. (1973). Methods of analysing competition with special reference to herbage plants. I. Establishment. J. agric. Sci., Camb. (in the Press).CrossRefGoogle Scholar
Jacquard, P. & Caputa, J. (1970). Comparaison de trois modèles d'analyse des relations sociales entre espèces végétales. Ann. Améior. Plantes 20, 115–58.Google Scholar
Mather, K. (1961). Competition and co-operation. Symp. Soc. exp. Biol. 15, 264–82.Google Scholar
Norrington-Davies, J. (1968). Diallel analysis of competition between grass species. J. agric. Sci., Camb. 71, 223–31.CrossRefGoogle Scholar
Perkins, Jean M. & Jinks, J. L. (1968). Environmental and genotype-environmental components of variability. III. Multiple lines and crosses. Heredity 23, 339–56.CrossRefGoogle Scholar
Samuel, C. J. A., Hill, J., Breese, E. L. & Davies, Alison (1970). Assessing and predicting environmental response in Lolium perenne. J. agric. Sci., Camb. 75, 1–9.CrossRefGoogle Scholar
Williams, E. J. (1962). The analysis of competition experiments. Avst. J. Biol. Sci. 15, 509–25.CrossRefGoogle Scholar
Yates, F. & Cochran, W. G. (1938). The analysis of groups of experiments. J. agric. Sci., Camb. 28, 556–80.CrossRefGoogle Scholar