Impact de la selection sur la variabilite genetique de l'epinette blanche au Quebec | Selection impact on genetic variability of white spruce in Quebec
1993
Desponts, M. | Plourde, A. | Beaulieu, J. | Daoust, G.
The genetic structure and variability of two natural white spruce (Picea glauca (Moench) Voss.) populations from southern Quebec were compared by isoenzymatic analysis with those observed from three superior provenances of the Great Lakes and St. Lawrence regions. Twenty 15- to 20-year-old trees, selected within the provenances and integrated into a diallel cross plan, were also studied. The analysis of seven enzymatic systems demonstrates, in an overall fashion, the consistency of variability within provenances when these are compared with natural populations. It indicates that the selection of a restricted number of individuals in these populations does not cause a significant loss of variability. The level of heterozygosity for the selected individuals integrated into the diallel cross plan appears very high and no loss of alleles is recorded when compared with the original provenances, despite the sizeable reduction in numbers. This result suggests that the second selection, in favour of individuals demonstrating a strengthened vigour, favored the most polymorph genotypes.
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