Efficient production of androgenic doubled-haploid mutants in barley by the application of sodium azide to anther and microspore cultures

The aim of this study was to establish a protocol for an efficient producti on of agronomical and/or physiological mutants from model (cvs. Igri and Co bra) and low-androgenic-responding (cv. Volga) cultivars of barley through the application of a mutagenic agent, sodium azide, to anthers and isolated microspores cultured in vitro. This technology offers the possibilities of screening for recessive mutants in the first generation, selecting for nov el genotypes from very large haploid populations, avoiding chimerism and ra pidly fixing selected genotypes as fertile true breeding lines. The mutagen ic treatment, 10(-3)-10(-5) M sodium azide, was applied during the anther i nduction pre-treatment or immediately after the microspore isolation proced ure. Out of 616 M-2 doubled-haploid lines characterised under field conditi ons, a total of 63 morphological and developmental independent mutant lines were identified. The percentage of M-2 doubled-haploid lines carrying muta tions per line analysed was 3.8% when 10(-4) M sodium azide was applied to anthers from the low-responding cv. Volga; this increased to 8.6% and 15.6% when 10(-5) and 10(-4) M sodium azide were applied to freshly isolated mic rospores from model cultivars.