Spruce Population Genomics

Spruce (Picea spp.) species are the dominant component of the circumboreal forest and one of the most reforested species groups in the world. They have become a reference among conifers for fundamental and applied genomics research. This chapter reviews the compelling progress made in the field of spruce population genomics, from the supportive field trials established by tree breeders to the release of complete sequences of their cytoplasmic and nuclear genomes to most recent applications in forestry. Initial efforts focusing on sequencing the spruce gene space resulted in the development of extensive genomic resources such as expressed sequence tags libraries, gene and single nucleotide polymorphism catalogs, genotyping arrays, and high-resolution genetic maps. During the last decade, these resources allowed to gain insights into a variety of topics such as phylogeography and phylogeny, introgression and speciation processes, as well as association mapping. Thanks to the recent advent of high-throughput genotyping and sequencing technologies, population genomics data are now being produced at an exponential rate, which translates into new applications and opportunities in conservation genetics and spruce breeding, such as genomic prediction.