Abstract Detail

Ferns at the extreme: the case of moonworts, grape-ferns and adder’s tongues of the family Ophioglossaceae

Mossion, Vinciane [1], Koenen, Erik [2], Grant, Jason [3], Croll, Daniel [1], Farrar, Donald [4], Kessler, Michael [2].

Diversity and diversification of the common moonwort ferns (Botrychium lunaria, Ophioglossaceae).

Botrychium lunaria (L.) Sw. is a group of closely related ferns species showing a widespread temperate-circumboreal distribution. Until recently, two species were recognized within this group, B. lunaria and B. crenulatum, but molecular studies in North America and Northern Europe have led to the identification and description of five new taxa (B. lunaria var. melzeri, B. neolunaria, B. nordicum, B. tunux, and B. yaaxudakeit Stensvold & Farrar). Similarly, uncharacterized genetic lineages were recently found throughout Eurasia. Here, we aim to assess the global diversity and investigate the diversification processes of the B. lunaria group with a strong focus on the understudied parts of Eurasia. We performed the first global phylogenetic study of the group including 513 accessions sequenced at four non-coding plastid loci (trnHGUG-psbA intergenic spacer, trnLUAA-trnFGAA intergenic spacer, matK intron, and rpl16 intron). We recovered ten well-supported monophyletic clades with three new Eurasian lineages. The time divergence estimates of B. lunaria lineages converged on the Pleistocene, which was marked by glaciation cycles. The complex population dynamics induced by these climatic events may have driven the radiation of the B. lunaria group. Population dynamics under such climatic oscillations was shown to be associated with adaptations to climatic or soil conditions in Alpine species. We evaluated the role of ecological factors in the diversification of the B. lunaria group using climatic variables and soil acidity. Climatic niches of lineages broadly overlapped but soil pH preferences underpin the phylogenetic structure suggesting that edaphic factors may have played a role in the diversification of the group. The improved assessment of the B. lunaria lineages highlights that half of the lineages were previously uncharacterized. We performed morphological analyses using herbarium sheets and high-resolution scans of the uncharacterized lineages. Based on a combination of morphological, molecular, and ecological evidence, we propose four new Eurasian species (B. himalayense, B. orientale, B. nemus, B. rotundum), and refine the description of a previously synonymized species (B. onondagense) occurring in both North America and Europe.

1 - University of Neuchâtel, Laboratory of Evolutionary Genetics, Neuchâtel, Switzerland
2 - University of Zürich, Department of Systematic and Evolutionary Botany, Zürich, Switzerland
3 - University of Neuchatel, Laboratory of evolutionary genetics, Emile-Argand 11, Neuchatel, Neuchatel, 2000, Switzerland
4 - Iowa State University, Ames, IA, 50011, United States


Presentation Type: Colloquium Presentations
Number: C4010
Abstract ID:593
Candidate for Awards:None

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