Genetic delimitation of Oreocharis species from Hainan Island

Abstract

Hainan Island harbours an extraordinary diversity of Gesneriaceae with 14 genera and 23 species, amongst which two species and one variety are recognised in the genus Oreocharis. These three Oreocharis taxa are all Hainan-endemics and show a complex geographical distribution pattern with considerable morphological intermixtures. In this study, we combined DNA (nuclear ITS sequences and cpDNAtrnL-trnF and ycf1b) to evaluate genetic delimitation for 12 Oreocharis populations from the island, together with morphological similarity analysis using 16 morphological traits. The results showed Hainan Oreocharis taxa were monophyletic with relative low genetic diversity within populations, highly significant genetic differentiation amongst populations and a significant phylogeographical structure. The 12 populations formed three genetically distinct groups, roughly correspondent to the currently recognised two species and one unknown lineage. The PCA analyses of morphological traits indicate three distinctive groups, differing mainly in petal colour and corolla shapes. The roles of river and mountain isolations in the origin and distribution of these three lineages are discussed.

Oreocharis jasminina (Gesneriaceae), a new species from mountain tops of Hainan Island, South China

“…Our former study showed the new species O. jasminina and the three other Hainanendemic taxa are homologous, indicating these species in Hainan Island had a common origin (Ling et al 2020). The new species is only found on mountain tops higher than 1200 m in two mountains, Mt.…”

“…One nuclear ribosomal DNA (nrDNA) sequence, the ITS region comprising spacer 1, the 5.8S gene and spacer 2 (White et al 1990) and one chloroplast DNA (cpDNA) intron-spacer region trnL-trnF (Taberlet et al 1991) were used in this study. Laboratory procedures followed Ling et al (2020) and newly-acquired sequences were deposited in GenBank (Table 2).…”

“…According to Möller et al (2011), Chen et al (2014) and Ling et al (2020), Oreocharis sinohenryi (Chun) Mich.Möller & A.Weber which had the closest phylogenetic relationships with the Hainan Oreocharis taxa was used as outgroup with sequences (Genbank with accession numbers HQ632913 and HQ633009). The original chromatograms from both directions of the ITS1/2 and trnL-trnF sequences were evaluated using Bioedit (Hall 1999) for base confirmation and contiguous sequences editing, then we manually aligned sequences, where necessary, using MEGA v.6.5 (Kumar et al 2008) and ambiguous positions were excluded from the alignments.…”

“…Bayesian Inference (BI) analysis was conducted using MrBayes version 3.1.2 (Huelsenbeck and Ronquist 2001) and Maximum Likelihood (ML) analysis was performed using MEGA v.6.5 (Kumar et al 2008). Both procedures followed the Ling et al (2020), based on the combined ITS1/2 and trnL-trnF sequences.…”

“…O. dasyantha Chun, O. dasyantha Chun var. ferruginosa Pan and O. flavida Merrill (Li and Wang 2005;Ling et al 2020), while each of these species shows considerable variations in morphological traits (Wei 2010;Ling et al 2020a).…”