Inheritance of isozymes in seed and bud tissues of blue and Engelmann spruce

Abstract

Thirteen loci from 11 enzyme systems were identified among full-sib and half-sib progeny of blue and Engelmann spruce. Eleven of the loci were expressed in bud, embryo, and megagametophyte tissue; the remaining two loci were expressed only in embryo and megagametophyte tissue. There were no mobility differences observed between loci expressed in seed and bud tissues. The mode of inheritance for 10 of the loci was confirmed based on progeny genotypic distributions. For the two loci not expressed in bud tissue, acid phosphatase (Acp-2) and diaphorase (Dia-2), inheritance was inferred from pooled segregation ratios of megagametophytes from open-pollinated seed from heterozygous females. The inheritance of glutamate oxaloacetate transaminase (Got-3) was also inferred from segregation ratios and diploid embryo phenotypes of open-pollinated progeny owing to a lack of variability at this locus among the 40 parents in the mating design. Two loci, aldolase (Ald) and malate dehydrogenase (Mdh-2), were monomorphic among the 20 parents of both species. Key words: isozymes, Engelmann spruce, blue spruce, Picea.