The genetic control of morphological and yield characters in Vicia faba L.

Complete diallel crosses were made within each of three populations of Vicia faba to examine the genetic control of morphological and yield characters. The Afghanistan and USSR populations consisted of five and the European of four genotypes. The phenotypic range of the genotypes in each population was similar for the characters studied.In each character additive gene effects were partly responsible for genetic variation but non-additive effects varied greatly in importance depending on the population examined. Differences were found in: a) the presence or absence of dominance; b) the partitioning of the dominant effects; c) the degree and direction of dominance; d) the presence or absence of epistasis; and e) the size of narrow-sense heritability estimates.It appears that in V. faba there exists much greater genetic variability than is evident by the examination of plant phenotypes. As different breeding techniques can be used to exploit different components of genetic variability, it is recommended that the possibility of differences in genetic architecture between geographical populations be taken into account in the planning of plant breeding programs. Advantage could then be taken of interactions between breeding methods and populations that are phenotypically but not genetically similar.