Changes in the gene pool composition of Scots pine depending on the mode of regeneration

Abstract

Silvicultural practices can alter forest genetic resources in unpredictable ways, thereby influencing the adaptive and evolutionary potential of forest populations. This is especially alarming in the case of species with more northern distribution centers, due to the lack of area that can be colonized further north. In this article, we studied the genetic diversity of the Scots pine seed tree stand in Poland, its natural regeneration, and two artificially established progeny plantations. The research aimed to determine whether the regeneration mode had affected the efficiency of the gene pool transmission from the maternal seed stand to its offspring. Using nuclear microsatellite markers we compared the parameters of genetic variation and allelic composition among the studied stands. The results showed that all stands represent a common genetic pool with slightly higher values of observed heterozygosity in the case of progeny plantations. Inbreeding was significant only in natural regeneration. All stands have gained and lost rare alleles compared to the maternal seed stand. Nevertheless, the analysis of population differentiation showed that the gene pool of the maternal stand had been transmitted more efficiently to the natural regeneration, though the difference was only minimal. Possible reasons for the differences in transmission efficiency between natural regeneration and artificially established progeny plantations mainly include variations in the number of mother trees and crossing patterns in different reproductive seasons. Furthermore, some individuals that grow in the studied progeny plantations may be natural regeneration of the neighboring stands. In light of the obtained results, we discuss the genetic considerations for establishing and using seeds from progeny plantations in Poland.