Induced intermedium mutants in barley: origin, morphology and inheritance

Among 103 intermedium mutants induced in two-row cultivated barleys, and localized to 11 int loci, 5 of which being represented by one mutant each, no definite preference to the type of mutagen applied was found. There are clear morphological distinctions among intermedium mutants belonging to different loci, but also among allelic mutants; and there is an obvious distinction between intermedium mutants and the mutants belonging to the locus hex-v. Among the int mutants, only the int-d alleles show dominance, which is variable among the 13 alleles studied and also for the individual d allele. F2 data from crosses among int mutants showed no undisputable linkage among the 9 int loci studied in their normal positions. In spite of factors disturbing this analysis, mainly phenotypic overlapping and the variable dominance characterizing locus int-d, the 9 loci int-a, -b, -c, -d, -e, -f -h, -i, and int-k may for practical purposes be considered to approach an independent inheritance in relation to one another.