DOI: 10.5061/dryad.rbnzs7hd9
title: Morphological and molecular data support the separate species status of Syringa fauriei in Korea

description: Syringa fauriei is an unresolved lilac taxon (Oleaceae) native to specific
 geographical areas and present in the rivers and valleys of Gangwon
 province in South Korea. It was first identified on Mt. Geumgang by Faurie
 in 1906 and recognized as an independent species. Nevertheless, S. fauriei
 has been controversial as a synonymous species for S. reticulata subsp.
 amurensis without clear evidence. Therefore, we conducted this study on
 the taxonomic position of S. fauriei by examining the morphological and
 molecular differences between S. fauriei and its related taxa, the S.
 reticulata complex. Phylogenetic relationships were also inferred using
 molecular markers of nuclear ribosomal DNA internal transcribed spacer
 (ITS1–5.8S–ITS2; ITS) and external transcribed spacer regions.
 Consequently, S. fauriei and its related taxa were classified into two
 distinct clades: S. fauriei and the S. reticulata complex. Morphological
 and molecular data revealed that S. fauriei was endemic to Korea. The
 species characteristics of S. fauriei were further described for taxonomic
 re-establishment.
description: Morphological dataset: Dried and
 liquid-preserved (fixed in 70 % ethanol) specimens for morphological
 analysis were collected during the flowering times (May to June 2020) from
 the four populations of <em>S. fauriei</em> and six
 populations of <em>S. reticulata</em> (synonym <em>S.
 reticulata</em> subsp. <em>amurensis</em>) in South
 Korea. Molecular dataset: PCR was conducted
 to amplify the nrDNA ITS and ETS regions using target gene-specific primer
 pairs. The reaction mixture included 20–100 ng template DNA and Dr.MAX DNA
 Polymerase. The other conditions were adopted as those described by Li et
 al. (2001). PCR conditions for gene amplification were as follows: a
 pre-denaturation step at 95 °C for 5 min, followed by 35 thermal cycles of
 denaturation at 95 °C for 30 s, annealing at 52 °C for 30 s, and extension
 at 72 °C for 1 min, followed by a final extension at 72 °C for 10 min. The
 PCR product was purified. The purified PCR products were then sequenced
 using Sanger-sequencing. Three primers (ITS4, ITS3B, and ITS-Leu) were
 used to sequence the entire ITS region, including 5.8S gene (Li et al.,
 2001). We used the primer pair (STT-ETS and 18S-ETS) to sequence the
 segment at the 3' end of the ETS region (Li et al., 2001). Nucleotide
 sequences were determined on both strands of the PCR amplification
 products at the Macrogen sequencing facility. The sequences obtained for
 each sample in both the forward and reverse orientations were assembled.
 The ETS and ITS sequences were aligned separately and then concatenated
 and manually adjusted. Information of the sample sources was attached as
 'source-table-sample'.
description: Data matrix of morphological
 characters was used to evaluate the morphological variations of
 <em>Syringa fauriei </em>and establish a relationship
 between<em> S. fauriei</em> and <em>S.
 reticulata </em>(synonym <em style="font-family:KievitWeb , sans-serif;font-size:medium;">S. reticulata</em> subsp. <em style="font-family:KievitWeb , sans-serif;font-size:medium;">amurensis</em>). There are some missing value, they
 has been filled using mean imputation.
 Sequence data matrix of nrDNA ITS
 and ETS regions was used to evaluate the sequence divergence of ETS and
 ITS and a phylogenetic relationship between <em>S.
 fauriei</em> and <em>S.
 reticulata </em>(synonym <em style="font-family:KievitWeb , sans-serif;font-size:medium;">S. reticulata</em> subsp. <em style="font-family:KievitWeb , sans-serif;font-size:medium;">amurensis</em>) using their related
 taxa.