Nuclear microsatellites for Pinus pinea (Pinaceae), a genetically depauperate tree, and their transferability to P. halepensis

Abstract

Pinus pinea is one of the few widespread plant species that are also genetically depauperate. It is also an important commercial species with high market value seeds. A deeper knowledge of the existing population genetic variation was needed. Twelve nuclear microsatellites were isolated from genomic and cDNA sequences and screened for variability in 729 individuals from 33 natural populations. Low level of genetic variability was confirmed with average expected heterozygosity of 0.11. Hardy-Weinberg equilibrium expectations were not met in only ∼10% of the possible locus/population combinations. All loci were in linkage equilibrium, and the frequency of null alleles was very low (≤1% in 332 out of 396 locus/population combinations). Nine out of the 12 microsatellites were successfully transferred to P. halepensis. Despite low polymorphism, these new markers will be useful to resolve population structure and hold potential for seed origin identification and traceability.