Does the genetic diversity among pubescent white oaks in southern Italy, Sicily and Sardinia islands support the current taxonomic classification?

Molecular diversity analysis of deciduous pubescent oaks was conducted for populations from Calabria, Sicily and Sardinia.
The aims of this study were twofold. First, to provide data on the genetic diversity of pubescent oaks from an understudied
area which currently exhibits one of the highest concentrations of pubescent oak species in Europe. Second, to verify if these
groups of oaks are genetically distinct and if their identification is in accordance with the current taxonomic classification.
Molecular analyses of leaf material of 480 trees from seventeen populations belonging to putatively different pubescent oak
species (Quercus amplifolia, Q. congesta, Q. dalechampii, Q. ichnusae, Q. leptobalanos, Q. virgiliana) were performed.
Twelve gene-based Expressed Sequence Tag-Simple Sequence Repeat markers were selected, and genetic diversity and
differentiation were calculated. The results showed relatively high values of allelic richness, heterozygosity and number of
private alleles for the populations investigated. A weak but positive correlation between geographical and genetic distance
was detected. Genetic assignment (STRU CTU RE) and principle coordinate analyses exhibited a weak separation into two
genetic groups which, however, did not correspond to the taxonomic, chorological and ecological features of the populations
investigated. Sardinian populations formed one group which was separated from the Calabrian and Sicilian populations. In
light of the results obtained, the taxonomic classification for the pubescent white oaks currently reported in the major Italian
floras and checklists for the study area was not confirmed by molecular analyses.