GENETIC ANALYSES OF A PUTATIVE MUTATOR-INDUCED DELETION INVOLVING THEBLUE FLUORESCENT1 (BF1) AND BROWN MIDRIB4 (BM4) LOCI IN MAIZE

A putative Mutator-induced alteration (isolate) involving the blue flu orescent1 (Bf1) and the brown midrib4 (bm4) loci is described. This is olate (Bf1-Mu-044-4) was one of the blue fluorescent1 mutants in a lar ge experiment designed to produce Mutator-induced mutations involving this locus. Evidence is presented supporting the conclusion that this alteration deletes all or part of both the bf1 and bm4 loci. The isola te is infrequently transmitted through the pollen, but is more readily transmitted through the egg, although at less than the expected frequ ency of 50% for a simple mutation. Heterozygotes of this isolate with the bm4-R allele have brown midribs. These brown midrib plants are sho rter than homozygous bm4-R plants and approximately 50% of these Bf1-1 Mu-044-4/bm4-R heterozygotes do not reach maturity. One putative Mutat or-induced bm4 mutation, which occurred in the course of the analysis of the Bf1-Mu-044 isolate, is described.