Influence of temperature during and after sodium azide treatment on M 1 damage and M 2 chlorophyll mutation in barley ( Hordeum vulgare L.)

Abstract

After sodium azide (NaN 3) treatment at different temperatures (5–35°C), barley seeds were exposed to temperature at 5–35°C for 24 hr. With proportionate increase in NaN 3-treatment temperature, delay of germination and yield of chlorophyll mutations increased but mutation frequency and the delay of germination were reduced by post-exposure to higher temperatures for each NaN 3 treatment: temperature group. The germination delay was virtually eliminated when the post-treatment was carried out at pH 7. The yield of chlorophyll mutations ranged from 0.61 to 6.86% for M 2 seedlings (a 10-fold difference), and from 7.9 to 28.9% for M 1 spikes. The results indicate an interaction between the mutagenic action of NaN 3 and repair of the induced lesions during germination.