Current approaches and perspectives in population genetics of Scots pine (Pinus sylvestris L.)

Scots pine (Pinus sylvestris L.) is one of the most ecologically and economically important forest-forming tree species in the Northern Hemisphere. Because of value, numerous genetic studies have been conducted since the 19th century to develop or improve the breeding and conservation programs of the species. Current studies are motivated by growing concerns about the survival and productivity of Scots pine populations, especially in the face of long-term environmental change predictions. In this article, we review major questions in the population genetics of Scots pine and show how previous studies advance current research approaches. We refer to major outcomes of the research describing the genetic variation and postglacial history of Scots pine compared with those of other cold-tolerant tree species such as Norway spruce (Picea abies) and silver birch (Betula pendula). We present results from studies of quantitative trait variation and local adaptation across the Scots pine distribution. We focus on the main research directions in dissection of the genetic basis of adaptive traits and the search for signatures of selection using quantitative trait locus mapping, candidate genes, association genetics, and genome scanning approaches. Finally, we highlight novel approaches in molecular breeding and point out new research prospects in genomic studies of Scots pine and other forest tree species in the face of rapid developments in next-generation sequencing and genotyping methods