| Seeds were collected from 3 pairs of peatland and adjacent upland black spruce (Picea mariana (Mill.) B.S.P.) populations at 3 sites to study ecotypic differentiation in black spruce in Alberta, Canada. The study consisted of 3 parts. In an allozyme study, 40 maternal trees/population were genotyped using 16 enzymes coded by 28 loci. Mean number of alleles/locus, percent of polymorphic loci, observed and expected heterozygosities, F;In the allozyme study, there was little genetic differentiation between the habitats. In the germination and greenhouse studies, seeds from upland trees germinated better and their seedlings grew faster, but seeds from different habitats had no adaptive responses to the treatments. Genetic variation within populations was similar between habitats. However, peatland populations had higher plasticity than upland ones, and there were significant site-dependent habitat differences for plasticity and other traits. Among sites, the populations from site 3 were the most different. Within habitats, upland populations were more variable in the allozyme study, but in the other studies, peatland ones were. Results from all three studies showed that peatland and upland black spruce was not well differentiated. Different sets of traits showed different variation patterns among populations, indicating different characters are controlled by different genes or gene complexes. |
