Neogene diversification in the temperate lichen-forming fungal genus Parmelia (Parmeliaceae, Ascomycota)

Abstract

The lichen-forming genus Parmelia Acharius occurs worldwide but its centre of distribution is in the northern hemisphere and it is widespread in boreal-temperate Eurasia and North America. Recent molecular work on Parmelia has identified phylogenetic relationships within two major groups of the genus: P. saxatilis s. lat. and P. sulcata s. lat. However, little is known about the diversification and historical biogeography of these groups. Here we have used a dataset of two genetic markers and 64 samples to estimate phylogenetic relationships within Parmelia. The dated phylogeny provides evidence for major diversification during the Neogene and Pleistocene. These diversification events are probably correlated with climatic changes during these periods. Evidence of gene flow within species between populations from North America and Europe has been found in three species: P. sulcata Taylor, P. saxatilis (L.) Acharius and P. barrenoae Divakar, M.C. Molina & A. Crespo. Cryptic species recently segregated on the basis of molecular differences (P. encryptata A. Crespo, Divakar & M.C. Molina vs. P. sulcata and P. saxatilis vs. P. mayi Divakar, A. Crespo & M.C. Molina) do not share a common ancestor. Moreover, the P. saxatilis complex is remarkably diverse. Two morphotypes of P. saxatilis s. lat. were shown to represent independent monophyletic lineages. Consequently, two species (P. sulymae Goward, Divakar, & M.C. Molina & A. Crespo and P. imbricaria Goward, Divakar, M.C. Molina & A. Crespo) are newly described here.

Key words:

• biogeographic distribution
• diversification
• evolution model
• Neogene
• Parmelia
• phenotypic plasticity
• phylogenetic relationship

Acknowledgements

This work was supported by the Spanish Ministerio de Ciencia e Innovación CGL2013-42498-P and a research grant from Rey Juan Carlos University to MCM (Estancias Breves de Investigación). The authors thank Alvaro Márquez (Universidad Rey Juan Carlos) and Edinson Sánchez (Universidad Rey Juan Carlos) for their comments and technical help, respectively. We are grateful to Lena Struwe (Rutger University) for providing laboratory facilities and financial support for sequencing some samples during MCM's visit to her laboratory. We are especially grateful to all the collectors for their invaluable participation. MCM gratefully acknowledges Rutgers University for hosting her as a Visiting Scientist. Finally, we thank Jason Hollinger for kindly granting us permission to use his photographs of P. imbricaria and P. sulymae.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

Supplemental data for this article can be accessed here: http://dx.doi.org/10.1080/14772000.2016.1226977.

Additional information

Funding

This work was supported by the Spanish Ministerio de Ciencia e Innovación [CGL2013-42498-P].