Genetic control of multiple esterases from needles and macrogametophytes ofPicea abies

The patterns of multiple esterases from needles and macrogametophytes ofPicea abies were examined by polyacrylamide-gel disc-electrophoresis. There are three patterns: (1) two slow-migrating bands, (2) three fast-migrating bands, and (3) a combination of (1) and (2). Re-electrophoresis of the individual bands and genetic analysis demonstrated the existence of two distinct isozymes controlled by two alleles at one locus. In a native population the esterase patterns were in a Hardy-Weinberg equilibrium. In the offspring of crosses between clonal grafts which represent individual trees with different esterase patterns, the patterns segregated in Mendelian ratios. In the haploid macrogametophytes of individual trees they also segregated as expected, i.e. in a 1:1 ratio. This latter fact allows a genetic analysis of individual trees without crossing experiments by investigation of the isozyme patterns only.