Abstract
Germination speed and germination uniformity were studied in F1 seeds of diallel crosses of six inbred lines of Nicotiana rustica under nine controlled environments differing in temperature, salt concentration and light condition. There was clear evidence of the additive and non-additive genetic effects on germination speed and germination uniformity. Maternal effects seemed to be involved. The genetic variation in germination speed was not associated with that ingermination uniformity. Rapid and uniform germination was dominant over slow and sporadic germination, respectively, although in some environments the dominance in germination uniformity was ambidirectional. The genotype-environment interactions were also observed. A significant part of the interactions could be explained by Jinear regression and deviations from the regression. The inheritance of linear response to environmental changes and the deviations from the regression were due to additive and maternal effects in both the germination characters. The response of germination speed to environmental changes was genetically independent of the response of germination uniformity.