CHARACTERIZATION OF AN Spm-CONTROLLED BRONZE-MUTABLE ALLELE IN MAIZE

Abstract
The association of a receptor (Rs) of the Spm system with a Bz-1 allele has created a two-element Spm-controlled bz-mutable allele (bz-m13) of maize (Zea mays L.). In the absence of Spm, one copy of bz-m13 (bz/bz/bz-m13) conditions full anthocyanin production in the aleurone layer of the seed. In the presence of this Spm, bz-m13 produces a unique, coarsely variegated seed phenotype and has a high rate (50–83%) of gametic change to stable bz′ or Bz′ derivatives. Even one copy of a Bz′ derivative allele conditions full anthocyanin production in the aleurone, but the enzyme (UFGT) level of the progenitor Bz-1 allele is not restored in most Bz′ derivatives.