Genetic characterization of the Galician maritime pine (Pinus pinaster) breeding population in Spain

Breeding population of Pinus pinaster in Galicia included 116 plus trees with desirable characteristics for height growth, wood quality and resistance to pests and diseases. These trees are represented by 452 ramets in a clonal seed orchard. Given the historical presence of afforestation with Castilian origin in the region, molecular markers were used to genetically characterize the breeding material. A total of nine microsatellites (SSRs) and 61 single nucleotide polymorphisms (SNPs) were used for genotyping. Clonal identification based on both marker types revealed 98 unique multilocus genotypes. We estimated the genetic diversity and the geographic origin of the Galician breeding population by comparing it with a representative sample of populations across the species’ European distribution. Our results provide sufficient genetic resolution to identify clones, correct misidentifications and assess the genetic diversity and structure of the breeding population, revealing an Atlantic Iberian origin. Altogether these results indicate that the Galician breeding population harbors wide genetic diversity, providing a solid foundation in the breeding program and enhancing its potential to adapt to future threats. These results are essential to guide future actions within the Galician breeding program.