Associations between Allozyme Genotypes and Quantitative Traits in Douglas-Fir [PSEUDOTSUGA MENZIESII (Mirb.) Franco].

Effects of maternal genotypes for eight enzyme loci on seven quantitative traits in 41 half-sib families were determined. Heritability estimates for the quantitative traits were highly significant and ranged from 0.57 to 0.86. Only six of 112 comparisons (56 comparisons for each of the genotypes and 56 for homozygous versus heterozygous contrasts) were statistically significant (P < 0.05). None of these significant comparisons could be associated with either a particular allele or a particular genotype. No heterotic effects were observed when the homozygous genotypes were compared with the heterozygous ones. Because the quantitative traits are highly correlated, a discriminant function analysis was performed to obtain the two most important canonical variates that accounted for 75% of the variance in the quantitative traits. There were no significant associations among enzyme loci and the two canonical variates. I conclude that, in this study, enzyme genotypic differences do not influence the quantitative traits to a major extent.