Genetic diversity and population structure of selected black spruce populations from northwestern and southeastern Canada

Black spruce (Picea mariana (Mill.) B.S.P) is a widespread transcontinental and important tree species of the Canadian boreal forest region, and is found in almost all forested regions of Canada. Genetic diversity and population structure of black spruce has only been examined within a limited range and within a single province in Canada. There is no reported information on comparison of genetic diversity and population structure of black spruce from selected northwestern and southeastern populations.;The objective of the present study was to determine and compare genetic diversity and population structure of four selected natural populations of black spruce sampled from the northwestern (Yukon (YK), Yellowknife (YE), and Alberta (AB)) and southeastern (New Brunswick (NB)) parts of Canada. Sixty individual trees were sampled from each of four populations and individual trees were genotyped for 10 nuclear microsatellite markers.;The northern YE and YK populations harboured lower genetic diversity, effective population size and latent genetic potential than the northwestern AB population and the southeastern NB population. Each of the sampled populations was found to be genetically distinct. The northern YK and YE populations showed high genetic similarity and gene flow between them. The AB and NB populations are genetically well differentiated from each other as well as from the YK and YE populations. The YK and YE populations may have originated from a common ancestor, whereas the AB and NB populations may have originated from separate ancestors. The results follow a classical population genetic pattern where geographically close populations show higher genetic similarities than geographically distant populations. To my knowledge, this thesis study is the first to assess and compare genetic diversity and population structure of black spruce from northwestern and southeastern populations.;Key words: Picea mariana, nuclear microsatellites, genetic diversity and population structure.