[The effect of mutated genes on the earliest stages of development of Pisum sativum].

Fifteen radiation-induced mutants of Pisum sativum with different characteristics were tested immediately after germination to determine whether genetically caused deviations from the parent line could be found. In 12 of these genotypes statistically significant differences in the speed of development were observed, two of the mutants showed a change in the number of secondary roots as well. In two cases in which the mutated gene has reduced penetrance, its influence on the speed of development was also restricted to part of the plants. - In those mutants which show superior growth at later stages of ontogeny, the first visible effect of the mutated gene is a strong retardation of growth, which changes into a sudden acceleration some days later. The most probable explanation of this reaction is that the mutants produce such a high concentration of growth substances that during the earliest and most sensitive stages of ontogeny their development is delayed.