Characterization of sympatric Platanthera bifolia and Platanthera chlorantha (Orchidaceae) populations with intermediate plants
A peer-reviewed article of this Preprint also exists.
Author and article information
Abstract
Platanthera bifolia and P. chlorantha are terrestrial and rewarding orchids with a wide Eurasian distribution. Although genetically closely related, they exhibit significant morphological, phenological and ecological differences that maintain reproductive isolation between the species. However, where both species co-occur, individuals with intermediate phenotypic traits, often considered as hybrids, are frequently observed. Here, we combined neutral genetic markers (AFLPs), morphometrics and floral scent analysis (GC-MS) to investigate two mixed Platanthera populations where morphologically intermediate plants were found. Self-pollination experiments revealed a low level of autogamy and artificial crossings combined with assessments of fruit set and seed viability, showed compatibility between the two species. The results of the genetic analyses showed the same genetic patterns of morphologically intermediate individuals with the P. bifolia group. These results are corroborated also by floral scent analyses, which confirmed a strong similarity in floral scent composition between intermediate morphotypes and P. bifolia. Therefore, this study provided a much more detailed picture of the genetic structure of a sympatric zone between two closely allied species and supports the hypothesis that intermediate morphotypes in sympatry could reflect an adaptive evolution in response to local pollinator-mediated selection.
Cite this as
2017. Characterization of sympatric Platanthera bifolia and Platanthera chlorantha (Orchidaceae) populations with intermediate plants. PeerJ Preprints 5:e3279v1 https://doi.org/10.7287/peerj.preprints.3279v1note This preprint is not peer-reviewed. You may wish to reference the subsequent peer-reviewed version of this article.
Author comment
This is a submission to PeerJ for review.
Sections
Supplemental Information
Morphological data from allopatric populations (summarized in Table 2)
Morphological data from Botton sympatric population (summarized in Table 2)
Morphological data from Bois Niau sympatric population (summarized in Table 2)
Genotype frequencies of species-specific markers in P. bifolia, P. chlorantha species and intermediate morphotypes of two sympatric zones (Table 3)
Viability index (calculated from the data in the previous file - see text)
Additional Information
Competing Interests
The authors declare that they have no competing interests.
Author Contributions
Fabiana Esposito conceived and designed the experiments, performed the experiments, analyzed the data, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper.
Nicolas J. Vereecken conceived and designed the experiments, performed the experiments, analyzed the data, contributed reagents/materials/analysis tools, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper.
Maddalena Gammella analyzed the data, wrote the paper, reviewed drafts of the paper.
Rosita Rinaldi performed the experiments, analyzed the data, contributed reagents/materials/analysis tools.
Pascal Laurent performed the experiments, analyzed the data, contributed reagents/materials/analysis tools.
Daniel Tyteca conceived and designed the experiments, performed the experiments, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper.
Field Study Permissions
The following information was supplied relating to field study approvals (i.e., approving body and any reference numbers):
Field experiments were approved by the Département de la Nature et des Forêts of the Walloon Region of Belgium.
Funding
This study was supported by grants-in-aid from the Fonds Scientifique de Recherche of the Université catholique de Louvain for two years between 2013 and 2015. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
