Changes in relative growth rate with plant ontogeny in spring wheat genotypes grown as isolated plants
- 71 Downloads
For a better insight in the effect of wide spacing on the outcome of plant selection in spring wheat, the growth of free-grown individual plants was followed in time for each of 12 cultivars. As time proceeded, the cultivar differences for per-plant weight showed progressively less relation with those for seedling weight. At anthesis, the genetic correlation with seedling weight was still about 0.80, but at final harvest it was only 0.06. This contrasted with the genetic correlation between seedling weight and final biomass in closely planted mixtures which was on the average 0.77. The outcome of selection of genotypes in isolation is therefore expected to deviate substantially from that of selection in densely planted segregating populations where the differences in initial size tend to be maintained in time.
The ranking of the varieties grown in isolation changed in time because of differences in relative growth rate (RGR). The genetic variance of RGR decreased much less with time than RGR itself. Late-flowering varieties showed the higher RGR so that these varieties improved their position in the ranking in isolation.
Special attention is paid to the methodology of plant growth analysis in variety experiments and in estimating means and variances of RGR.
Index wordsTriticum aestivum wheat growth analysis relative growth rate selection
Unable to display preview. Download preview PDF.
- Causton, D. R. & J. C. Venus, 1981. The biometry of plant growth. Edward Arnold, London, 307 pp.Google Scholar
- Cochran, W. G. & G. M. Cox, 1957. Experimental designs. John Wiley & Sons, New York, 2nd ed., 611 pp.Google Scholar
- Comstock, R. E. & R. H. Moll, 1963. Genotype-environment interactions. In: W. D. Hanson & H.F. Robinson (Eds), Statistical genetics and plant breeding. Nat. Acad. Sci., Nat. Res. Council, Washington DC, Publ. 982: 164–194.Google Scholar
- Fasoulas, A. & A. Tsaftaris, 1975. An integrated approach to plant breeding and field experimentation. Dept Genet. Plant Breed., Aristotelian Univ., Thessaloniki, Greece, Publ. 5, 37 pp.Google Scholar
- Hunt, R., 1982. Plant growth curves. Edward Arnold, London, 248 pp.Google Scholar
- Kramer, Th., 1984. Fundamental considerations on the density-dependence of the selection response to plant selection in wheat. Proc. 6th Int. Wheat Genetics Symp. Kyoto, Japan: 719–724.Google Scholar
- Richards, F. J., 1959. A flexible growth function for empirical use. J. exp. Bot. 10: 290–300.Google Scholar
- Richards, F. J., 1969. The quantitative analysis of growth. In: F. C. Steward (Ed.), Plant physiology, V A: Analysis of growth, Behavior of plants and their organs. Academic Press, New York, pp. 3–76.Google Scholar
- Snedecor, G. W. & W. G. Cochran, 1967. Statistical methods. Iowa State Univ. Press, Ames, Iowa, 6th ed., 593 pp.Google Scholar
- Spiertz, J. H. J. & H. van Keulen, 1980. Effects of nitrogen and water supply on growth and grain yield of wheat. Proc. 3rd Int. Wheat Conference, Madrid, pp. 595–610.Google Scholar
- Schapendonk, A. H. C. M. & C. J. T. Spitters, 1984. Interplant competition as a biasing factor in evaluating pre-treatment effects in cucumber. Scientia Hortic. 24: 115–122.Google Scholar
- Spitters, C. J. T., 1979. Competition and its consequences for selection in barly breeding. Agric. Res. Rep. (Versl. landbouwk. Onderz.) 893: 268 pp.Google Scholar
- Spitters, C. J. T., 1984. Effects of intergenotypic competition on selection. In: W. Lange, A. C. Zeven & N. G. Hogenboom (Eds.). Efficiency in plant breeding: Proc. 10th Congr. Europ. Ass. Res. Pl. Breed., EUCAPPIA. Pudoc, Wageningen, pp. 13–27.Google Scholar
- Spitters, C. J. T. & Th. Kramer, 1985. Differences between spring wheat cultivars in early growth. Euphytica 34: 000–000.Google Scholar