Induced polygenic variation and genetic architecture in Indian mustard

Summary The F₁ seed obtained from an eight-parent diallel (excluding reciprocals) in Indian mustard was treated with 100 Kr of gamma rays, grown and selfed to obtain F₂M₂. The mean was decreased in the majority of the crosses in an irradiated set whereas the coefficient of variation increased. Combining ability analysis revealed the change in relative ranking of the parents and crosses and suggested the genotype-specific responses to irradiations. Components of combining ability and heterosis were also changed considerably. In some cases irradiation resulted into an increase in additive genetic variance.