Environmental and genotype-environmental components of variability VI. Diallel sets of crosses

Abstract

1. In a previous paper (Perkins and Jinks, 1968) an analysis of the genotype-environmental interactions of F1’s was given. This has now been extended to take full advantage of the systematic relationships that exist between F1’s belonging to a diallel set. 2. The principal merit of the new analysis is that direct comparisons can be made between the F1’s of a diallel set for the linear and non-linear components of their interaction with the environment. 3. The new analysis is illustrated with the final height data of a diallel set of crosses among eight inbred lines of Jficotiana rustica and the results are compared with those of the previous analysis. 4. The F1’s of N. rustica have on average a higher performance and a higher sensitivity to environmental change than their inbred parents and the crosses mainly responsible for these high values are those which are known to have an epistatic contribution to their generation means. 5. Modifications to the definitions of the genetic, environmental and genotype-environmental interaction parameters of the diallel that are necessary in the presence of epistasis are given. 6. The combined effect of genotype-environmental and non-allelic interactions on the degree of heterosis and on the selection of commercially acceptable genotypes are discussed. © 1970, The Genetical Society of Great Britain. All rights reserved.