Genetic analysis of black spruce populations (Picea mariana (Mill.) B.S.P.) from wetlands and dry lands contaminated with metals from the Greater Sudbury (Canada): Application of ISSR and microsatellite markers.

摘要

Genetic variation and structure of black spruce ( Picea mariana (Mill.) B.S.P.) populations growing in wetlands and uplands (dry lands) with different levels of metal contamination were analyzed using ISSR and microsatellite markers. The percentage of polymorphic loci (P%) detected with ISSR primers ranged from 65% to 90% with a mean of 75%. Nei's gene diversity (h) varied from 0.264 to 0.359 with an average of 0.310, and Shannon's index (I) ranged from 0.381 to 0.524 with an average of 0.449. The level of genetic variation was higher in populations from wetlands than those from dry lands. Variation within populations accounts for most of total genetic variation. Long exposure (more than 50 years) to high concentrations of metals was not associated with the level of genetic variability. The genetic distance among the Picea mariana populations ranged from 0.171 to 0.351. The dendrogram constructed, based on ISSR data revealed a particular grouping between dry and wet land populations. None of the dry land population clusters with a population from a wetland. Microsatellite analysis revealed that the mean number of alleles per locus was 10.3 and the mean number of effective alleles was 5.595 in the black spruce populations. The observed and expected heterozygosities ranged from 0.119 to 0.256 and from 0.737 to 0.804, respectively. The population differentiation was found to be low with a value of 11.0%. Overall, the results of the present study indicate that black spruce populations from the Greater Sudbury region meet most of genetic criteria of sustainability.