The Pinus nigra distribution in Portugal is restricted to six allochthonous populations with unknown origin and infraspecific taxonomy. This work intends to evaluate their genetic diversity, structure and relationships, and to infer about their infraspecific taxonomy by comparing molecular patterns produced by inter-simple sequence repeat and Start Codon Targeted markers among Portuguese and foreign samples with known taxonomy and provenance. 127 Portuguese P. nigra individuals were clustered per population. The genetic differentiation was higher within rather than among populations. The pooled molecular data indicated high genetic proximity among the Portuguese and foreign samples of subspecies laricio. However, the separate analysis per marker system demonstrated that two varieties of subspecies laricio (corsicana and calabrica) may have been used in the plantations of the Portuguese P. nigra stands performed in the last century. The genetic characterization and extrapolation of the intraspecific taxonomy of these populations provide useful information for forest management, afforestation and germplasm use.

Keywords: European black pine; Genetic structure; Infraspecific taxa; Molecular markers.