Abstract
The <em>Hepatica </em>section <em>Angulosa </em>consists of mainly tetraploid (2<em>n </em>= 28) species that are distributed disjunctly throughout Eurasia. Karyological evidence proves the hybrid origin of the polyploid species of this section. <em>Hepatica transsilvanica </em>is a member of this species group with a conspicuous distribution restricted to the Eastern Carpathians. Based on genome size and cytotypes, the paternal parent of <em>H. transsilvanica </em>is described to be the only diploid species in section <em>Angulosa</em>, <em>H. falconeri</em>. The maternal species is hypothesized to be <em>H. nobilis</em>, a European species with entirely lobed leaves and a wider distribution area. Although the hybrid origin of <em>H. transsilvanica </em>is well documented by karyological evidence, the time of hybridization has never been studied. By using sequences of both the nuclear and plastid genome, we reconstructed the phylogenetic relationships and divergence times of <em>H. transsilvanica </em>and its parental species. The identity of the parental species is corroborated by discordant gene tree topologies of the nrITS and plastid sequences. Moreover, both gene copies of the parental species could be identified with the low-copy nuclear gene, <em>MLH1</em>. Divergence dating analysis using Bayesian phylogenetic methods strongly supported the long-term survival of <em>H. transsilvanica </em>in the Southeastern Carpathians, as the most recent common ancestor of the hybrid and parent species existed not later than the beginning of the Pleistocene, ca. 3 million years ago. These results not only highlight the biogeographic importance of the Southeastern Carpathians in the Quaternary glaciation periods, but also emphasize that Tertiary lineages could have survived in a Central European cryptic refugium.
Highlights
Hepatica is traditionally known as a small genus within Anemoninae (Ranunculaceae) that comprises seven to nine species depending on the taxonomic concept applied (Tamura, 1993; Weiss et al, 2002)
The distribution area of H. transsilvanica is restricted to the Southeastern Carpathians in Romania (Kliment et al, 2016), whereas H. nobilis Mill. – the only species of the genus in Europe that belong to the section with entirely lobed leaves – has a much wider distribution area, which covers most of Europe (Figure S1)
We found two positions that showed an additive pattern between H. nobilis and H. falconeri
Summary
Hepatica is traditionally known as a small genus within Anemoninae (Ranunculaceae) that comprises seven to nine species depending on the taxonomic concept applied (Tamura, 1993; Weiss et al, 2002). S.: the mainly diploid section Hepatica (2n = 14) is characterized by species with entirely lobed leaves, whereas the predominantly polyploid section Angulosa (2n = 28) consists of crenateleaved species (Zonneveld, 2010). The genus shows both inter- and intracontinental disjunct distribution, with the highest species diversity in Northeast Asia (Pfosser et al, 2011). – the only species of the genus in Europe that belong to the section with entirely lobed leaves – has a much wider distribution area, which covers most of Europe (Figure S1) Other species of this latter section occur in E Asia and N America (Pfosser et al, 2011, Figure 1)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
