5S nuclear ribosomal DNA reveals cryptic diversity within the Fagus orientalis Lipsky alliance (Fagaceae) in Turkey

We perfomed HTS Illumina Sequencing of the nuclear 5S rDNA intergenic spacers to address taxonomy, diversity and evolution of the small isolates of Oriental beech (Fagus orientalis s.l. Lipsky) thriving at the south-easternmost edge of the genus range in Western Eurasia (Nur Mountains, South Anatolia). Data from 15 populations covering all four Western Eurasian beech species were used to assess their geno-taxonomic affinities and evolutive relationships. Three East Asian relatives of the Western Eurasian beeches (members of F. subg. Fagus) were included as comparison: F. crenata, F. hayatae, F. pashanica. Distinctiveness of the Nur Mountains beeches is expressed in the quantitative (number of exclusive) and qualitative (characteristic molecular features) composition of the detected 5S-IGS Operational Taxonomic Units (OTUs). Simultaneously generated 5S-IGS Amplified Sequence Variants (ASVs) showed a peculiar evolutionary imprint highlighting the ancestral nature the Nur Mountains population within the Euro-Euxinian (F. orientalis [s.str.] + F. sylvatica L.) and the Caucasian F. hohenackeriana Palib. species lineage. Our data suggest that that the Nur Mountains beeches are directly derived from the common ancestor of F. orientalis-F. sylvatica and retain sequence variants partly lost in all northwestern relatives.This fileset includes basic information on the working data, the used alignments and resultant inference files.Map—a GoogleEarth® file showing the distribution of the sampled populations.File S1—Details and geograpical location of the studied samples/populations, with Circos plots detailing their genetic (5S-IGS OTUs) composition;File S2—multiple spread-sheet (XLSX) file listing the abundance and characterisation of the OTU representative sequence detected in each sample/population;File S3—multiple spread-sheet (XLSX) file listing the abundance and characterisation of the ASV representative sequence detected in each sample/population;Supplementary Data Archive (SDA)—zipped data matrices and analyses files (including OTUs and ASVs MSAs, RAxML trees, PBC transformation and Neighbor-Net files); see _ReadMe.txt for archive's content.