[en] The alcohol dehydrogenase-1 gene in maize presented advantages for mutational analysis. Foremost among these is the ability to select chemically ADH-negative and ADH-low gametotypes owing to their resistance to allyl alcohol vapour. Immature tassels were irradiated with either 220 kV X-rays or 400MeV/amu accelerated neons-ions; spontaneous mutants were also selected and recovered. RBE for neon-20 was about 5. A total of 70 presumptive mutants were placed into one of four classes on the basis of allozyme profiles following electrophoresis and ADH staining: (A) dysfunction, (B) underproducer, (C) overproducer, and (D) up-Adh2 gene. Mutants have been recovered and confirmed in the first three classes. These include two male-transmissible deletion-type lesions induced by X-rays, five underproducer transpotitions and one overproducer transposition induced by neon-20. Certain of the neon-induced alleles were unstable in their expression. All 70 mutants are chromosomal aberrations; no intragenic lesions were recovered although the experimental design would have preferentially recovered them if they had occurred. The mutagenic action of ionizing radiation is considered, and especially the well-documented differences between maize and Drosophila data. In particular, the effect of these chromosome derangements on the 'programmable' component(s) of the Adhl cistron is discussed. (author)