The role of environmental factors in the formation of the genetic structure of P. аbies populations

Summary: Background. Norway spruce (Picea abies (L.) Karst.) is one of the main forest forming spruce species in Europe. Their populations are characterized by the genetic heterogeneity between individuals in population. The genetic structure of P. abies populations studied supported a hypothesis of an environment impact on the degree of genetic differentiation among populations. Materials and methods. Analysis of genetic diversity of natural populations in distinct geographical regions from North-West Russia, South-West Russia, South Norway were done using nuclear microsatellites. The needles were collected from the 20-30 adult trees in each geographical spot taking into account the local environment. The statistical calculations were performed with GenAlEx 6.5.03 and Structure 2.3.4. Results. The analysis highlighted the environmental impact on the genetic diversity. The genetic structure of spruce cenopopulations from poor conditions are extremely different from those of cenopopulations growing under rich environmental conditions in one geographic region. The genetic differences between them are comparable with the genetic differences between spatially remote populations. Conclusion. The role of the isolation by environment as a pattern in which genetic differentiation increases with environmental differences independent of the geographic distance is essential for genetic structure of spruce populations.