Parabolic effect in sodium azide mutagenesis in barley*

Abstract

In order to study the influence of sodium azide concentration on its mutagenic effect, treatments with this chemical (0, 1X10-4 5X10-4 1X10-3 5X10-3 M, pH 6, 20 h.) were applied to seeds of the two-row barley variety Malteria Heda and its double-mutant MC 90. In both genotypes the highest mutagenic effect was observed in the intermediate azide concentrations. The plotted data described a second degree parabole in relation to the azide molarity. The parabolic effect was presented in both forms of recording (chlorophyll mutations/ M1 spikes, and chlorophyll mutants/ M2 seedlings), and it was also found in ovule sterility. On the other hand, the results in physiological vitality, chromosome damage and survival of M1 mature plants were similar to or slightly different from those of the untreated controls.