A mutant induced in the malting barley cv Triumph with reduced dormancy and ABA response

Induced mutants in the barley cultivar Triumph have been screened for reduc ed dormancy. One line, which germinated readily 2 weeks after harvest, was classified as ABA-insensitive, since it could tolerate a ten-fold increase in ABA, compared to its parent, before germination was inhibited. This muta nt, designated TL43, was genotypically similar to Triumph and phenotypicall y similar under Scottish growing conditions, except for a slightly reduced grain size. In Spain, it showed considerable reductions in both grain yield and plant height, suggesting that it was less widely adapted than its pare nt. Levels of alpha-amylase activity were increased at both sites. The muta nt appeared to be different from those with ABA insensitivity or altered do rmancy previously documented in either barley or Arabidopsis.