Management and Genetic Diversity of an Italian Pistacia Collection Through Microsatellite Markers

Conservation and characterization of germplasm collections are essential for safeguarding agrobiodiversity and supporting breeding programs. A collection of 140 accessions comprising three different Pistacia species, P. integerrima, P. terebinthus, and P. vera, was analyzed using 27 EST-SSR markers. On average, 3.4 alleles per locus, and 28.2% rare alleles were found. Observed heterozygosity (Ho = 0.36) was lower than expected (He = 0.48), while five loci displayed PIC values above 0.50, highlighting their high informativeness. The phylogenetic analysis clearly separated the three species. Among P. vera samples, Nj tree and population structure analysis identified three main sub-groups: Eastern Mediterranean/Middle Eastern accessions, Italian traditional cultivars, and US modern cultivars. The first group showed higher internal variability, reflecting both local diversification and historical genetic exchanges. Through the use of EST-SSR markers, the present study assesses the genetic diversity within the Pistacia collection while highlighting errors due to mislabeling issues. These results confirm the effectiveness of microsatellite markers to provide a framework for the management and exploitation of genetic diversity for breeding and conservation strategies, also in the Pistacia genus.