Environmental and genotype-environmental components of variability VIII. Relations between genotypes grown in different environments and measures of these environments

Genotype-environmental interactions in Schizophyllum commune I. Analysis and character

“…The genotype-environmental analysis of Freeman and Perkins (1971) was carried out using the mean performance, over blocks, of the F1 control dikaryon to provide an independent assessment of the environments. Following Freeman and Perkins (1971) b denotes the regression coefficient of the ith genotype in this analysis.…”

“…The first (Finlay and Wilkinson, 1963;Rowe and Andrew, 1964;Eberhart and Russell, 1966;Breesc, .1969) is a purely statistical approach, whereas the second (Perkins and Jinks, 1968;Baker, 1969) and a third derived from it (Freeman and Perkins, 1971) relate the components in the regression analysis to the basic biometricalgenetical model given by Perkins and Jinks (1968). The definitions of the d and gij parameters in this model (No.…”

“…This partitioning is implicit in any examination of the individual regression lines with approach 2 and, although possible arithmetically, is not valid statistically as too few degrees of freedom are available. The sensitivities of individual genotypes can only be compared by partitioning the total within genotypes sum of squares, which contains both the between environments and the genotype x environment components (Freeman and Perkins, 1971). …”

Magnification through competition of genetic differences in yield capacity in carp

“…This concept was further elaborated in a series of reports (e.g. Perkins and Jinks, 1968;Freeman and Perkins, 1971). Their model, corresponding to equation 9, can be presented (in the present notations) as = (12) In all these reports the writers were primarily interested in expressing genotype-environment interactions as functions of the environment (a).…”

“…Freeman and Perkins (1971) showed that when the environment is measured independently of the data used for estimating the regression coefficient f3 (of equation 12 or /3 plus sg of equation 14) then / the mean of all the 8/s, is not necessarily equal to one. Consequently, equation 14 may assume an even more generalised form by substituting (+)a1 for (1 + j3) a.…”