Induction and selection of specific gene mutations in hordeum and pisum

Abstract

Barley ( Hordeum vulgare L.) and pea ( Pisum sativum L.) seeds were treated with the mutagen sodium azide. The second generation (M 2) seeds or seedlings were screened for physiological (nitrate reductase-deficient and chlorate-resistant) mutants and presumed single locus (waxy endosperm and vine) mutations. Nitrate reductase-deficient mutants occured at an overall frequency of 13.1 per 10,000 seedlings in barley and 3.5 per 10,000 seedlings in peas. Chlorate-resistant mutants occurred at a frequency of 6 per 10,000 seedlings in barley. Waxy endosperm mutants occurred at a frequency of 2.7 per 10,000 seeds and vine (gigas) mutants occured at a frequency of 1.0 per 10,000 seedlings in barley. These data demonstrate that specific gene or function mutations occur with high frequency in azide-mutagenized barley and peas and indicate that similar loss of function mutants could be selected for in higher plants with even relatively laborious screening techniques.