Induction of breviaristatum mutants in barley

Abstract

Short-awned (breviaristatum) mutants were induced in the barley varieties Bonus, Foma and Kristina by ionizing radiations (X- and γ-rays, neutrons) and by chemical mutagens (chiefly sulfonates and ethyleneimine) About 260 mutants were isolated and certified in 1953–1972. Of those tested for allelism approximately 140 were distributed into 17 loci represented by 2 to 26 allelic mutants. Two loci have a single allele. The skew distribution of mutants at different loci is evident. Mutation rates and proportions were determined in M2 progenies during four years of screening. Chlorophyll mutations were approximately 25 times more frequent than breviaristatum types. Among the morphological mutants, erectoides, eceriferum and breviaristaturn types were approximately equally common. In general, chemical mutagens were 2–3 times more efficient than radiations in the induction of all kinds of mutation. Differences in detectability of mutant groups depending on parent variety are briefly discussed. A brief phenotypical description of the individual breviaristatum (ari) loci is given, illustrating the pleiotropic effects often found. Mutants in loci ari-a, -c, -d, -e, which have previously been placed on the chromosome map, may serve as good marker genes. Mutants of loci ari-1 and -m are of some practical interest owing to their stiff short straw and prolific spikes.