Combining molecular analyses with geological and palaeontological data may reveal timing and modes for the divergence of lineages within species. The Mediterranean Basin is particularly appropriate for this kind of multidisciplinary studies, because of its complex geological history and biological diversity. Here, we investigated chloroplast DNA of Quercus suber populations in order to detect possible relationships between their geographical distribution and the palaeogeographical history of the western Mediterranean domain. We analysed 110 cork oak populations, covering the whole distribution range of the species, by 14 chloroplast microsatellite markers, among which eight displayed variation among populations. We identified five haplotypes whose distribution is clearly geographically structured. Results demonstrated that cork oak populations have undergone a genetic drift geographically consistent with the Oligocene and Miocene break-up events of the European-Iberian continental margin and suggested that they have persisted in a number of separate microplates, currently found in Tunisia, Sardinia, Corsica, and Provence, without detectable chloroplast DNA modifications for a time span of over 15 million years. A similar distribution pattern of mitochondrial DNA of Pinus pinaster supports the hypothesis of such long-term persistence, in spite of Quaternary climate oscillations and of isolation due to insularity, and suggests that part of the modern geographical structure of Mediterranean populations may be traced back to the Tertiary history of taxa.

DNA barcoding may be particularly important in influencing ecology, economic issues, and the fundamental crisis facing biodiversity as a standardized, species-level identification tool for taxonomy assessment. Trees play important roles in the conservation of many land ecosystems, the wood trade, and the definition of biogeographical processes; nevertheless, peculiar biological, evolutionary and taxonomical features will probably constitute an intriguing challenge to barcoders. We examined whether four marker regions (trnh-psba, rbcL, rpoc1, matK) proposed by the Consortium for the Barcode of Life (CBOL) matched species taxonomy in a preliminary tree biodiversity survey of Italian forested land. Our objective was to provide a test of future in situ applications of DNA barcodes by evaluating the efficacy of species discrimination under the criteria of uniformity of methods and natural co-occurrence of the species in the main forest ecosystems. Fifty-two species were included in a floristic study. We obtained 73% total discrimination success, with trnH-psbA as the best performing marker and oaks as the least responsive plants to the markers used. A further taxon-based study of Quercus (thirty specimens, 12 species) revealed that this genus is refractory to barcoding (0% discrimination success), a probable consequence of low variation rate at the plastid genome level, hybridization, and the incidence of biogeography. We conclude that some species-rich tree genera in small geographical regions may prove exceptionally difficult to barcode. Until more efficient markers are developed, we recommend that improved and diversified sampling (multiple locations of sympatric and co-occurring congenerics) be embraced as a timely and important goal for the precise assessment of haplotype specificity to facilitate the productive application of barcoding in practice.

Nuclear ribosomal DNA sequences encoding the 5.8S RNA and the Xanking internal transcribed spacers (ITS1 and ITS2) were used to test the phylogenetic relationships within 12 Italian Quercus taxa (Fagaceae). Hypotheses of sequence orthology are tested by detailed inspection of some basic features of oak ITS sequences (i.e., general patterns of conserved domains, thermodynamic stability and predicted conformation of the secondary structure of transcripts) that also allowed more accurate sequence alignment. Analysis of ITS variation supported three monophyletic groups, corresponding to subg. Cerris, Schlerophyllodrys ( D Ilex group sensu Nixon) and Quercus, as proposed by Schwarz [Feddes Rep., Sonderbeih. D,. A derivation of the "Cerris group" from the "Ilex group" is suggested, with Q. cerris sister to the rest of the "Cerris group." Quercus pubescens was found to be sister to the rest of the "Quercus group." The status of hybrispecies of Q. crenata (Q. cerris £ Q. suber) and Q. morisii (Q. ilex £ Q. suber) was evaluated and discussed. Finally, the phylogenetic position of the Italian species in a broader context of the genus is presented. The utility of the ITS marker to assess the molecular systematics of oaks is therefore conWrmed. The importance of Italy as a region with a high degree of diversity at the population and genetic level is discussed. 

AB The Azores provide an excellent field test for research activities aimed\ud at developing conservation strategies for endangered tree species. In\ud this work, the urgency to promote Picconia azorica conservation programs\ud addressed (a) insights into the biotaxonomy of the species (including an\ud evaluation of its origin and relationships with the only congeneric\ud species of P. azorica: P. excelsa from the Canary and Madeira islands)\ud and (b) the evaluation of P. azorica genetic diversity. Plastid DNA\ud sequence analysis and molecular markers (RFLP and SSR) were used for\ud this purpose. Phylogenetic data suggest the monophyly of Picconia and\ud support a late Miocene divergence of the two species. Three polymorphic\ud cpSSR loci allowed the identification of five different haplotypes in P.\ud azorica. Uniqueness and relictuality of lineages are presented and\ud discussed. Picconia azorica intra-specific diversity patterns revealed\ud low genetic diversity and a weak genetic structure, which could result\ud from long-lasting ecological stability and efficient inter-island seed\ud movement that have been severely affected in recent times. The species\ud survival is at risk, and we suggest management practices focusing on ex\ud situ and in situ conservation units based on eco-genetic data.\ud Additional measures contributing to mild erosion of the genepool and to\ud remove barriers to seed dispersal are indicated

Nuclear (AFLPs and ITSs) and chloroplast DNA markers (cpDNA) were analysed in Quercus suber L., Q. ilex L. and Q. coccifera L. in order to detect vicariant patterns in the Western Mediterranean Basin populations. Clustering methods, i.e., parsimony, minimum spanning network, UPGMA and PCO, were used to obtain robust phylogenies. The Mantel test was used to check the geographic structure of the populations. Nuclear markers’ based phylogenies showed high bootstrap values at basal nodes of clusters indicative of species. Within species, Q. suber and Q. ilex showed three and two groups respectively with strong geographic structure for cytoplasmic and nuclear markers. In contrast, Q. coccifera had overlapping cpDNA lineages and nuclear markers did not show any group with strong geographic structure. Taxonomic assignation of the species was well‐supported by our data. Ongoing allopatric speciation was inferred for Q. suber and Q. ilex derived from Pliocene vicariant events. Quercus coccifera showed a more homogeneous genetic pattern in the Western Mediterranean.