Summary
One of the considerations of regional cultivar evaluation programs is to optimize the number of locations used for testing. Although optimization of numbers of locations using cluster analysis has been previously attempted, no objective comparison of methods has yet been made. A new clustering method that uses the pairwise contribution of locations to the cultivar x location mean square as the distance measure (LB) was compared to another method that employs diallel correlations as the distance measure (CL). Data from six spring wheat (Triticum aestivum L. em Thell) cultivars grown at 13 locations for five years were used in the initial cluster analysis. Another set of data, from a separate year, consisting of yields of the original 6 cultivars and a set of 12 independent cultivars was then used to check the validity of the original groupings and to compare the two methods. When the 6 original cultivars were considered, the LB technique was found to be superior to the CL. When the 12 independent cultivars were used, neither method was considered to be superior. Because of the lack of flexibility on the part of the LB method, neither technique could be deemed as fully adequate.
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References
Baker RJ (1988) Tests for crossover genotype-environmental interactions. Can J Plant Sci 68:405–410
Campbell LG, Lafever HN (1977) Cultivar x environment interactions in soft red winter wheat yield tests. Crop Sci 17:604–608
Guitard AA (1960) The use of diallel correlations for determining the relative locations performance of varieties of barley. Can J Plant Sci 40:645–651
Lin CS (1982) Grouping genotypes by a cluster method directly related to genotype-environment interaction mean square. Theor Appl Genet 62:277–280
Lin CS (1988) Current status of statistical development at SRS for analyzing plant breeders data. SRS News 133:7–11
Lin CS, Butler G (1988) A data-based approach for selecting locations for regional trials. Can J Plant Sci 68:651–659
Rasmusson DC, Lambert PF (1961) Variety x environment interactions in barley variety tests. Crop Sci 1:261–262
SAS Institute (1985) SAS Users guide: statistics, 5edn. SAS Institute, Cary, N.C.
Sokal RR, Michener CD (1958) A statistical method for evaluating systematic relationships. Univ Kansas Sci Bull 38: 1409–1438
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Communicated by A. R. Hallauer
Contribution Number 842 of the Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada
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Brandie, J.E., Arthur, L.M. A comparative evaluation of two methods of selecting locations used for testing spring wheat cultivars. Theoret. Appl. Genetics 83, 301–304 (1992). https://doi.org/10.1007/BF00224275
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DOI: https://doi.org/10.1007/BF00224275