Botrychium; phylogeography; biparental inheritance; genome scan; local adaptation; ferns; population genetics; systematics; polyploidy; landscape genetics; Ophioglossaceae
Benjamin Dauphin Jason R. Grant Donald R. Farrar Carl J. Rothfels (2018), Rapid allopolyploid radiation of moonwort ferns (Botrychium; Ophioglossaceae) revealed by PacBio sequencing of homologous and homeologous nuclear regions, in Molecular Phylogenetics and Evolution
, 120, 342-353.
Benjamin Dauphin Donald R. Farrar Alessio Maccagni and Jason R. Grant (2017), A Worldwide Molecular Phylogeny Provides New Insight on Cryptic Diversity Within the Moonworts (Botrychium s. s., Ophioglossaceae), in Systematic Botany
, 42(4), 620-639.
Benjamin Dauphin Jason Grant Patrik Mraz (2016), Ploidy level and genome size variation in the homosporous ferns Botrychium s.l. (Ophioglossaceae), in Plant Systematics and Evolution
, 302, 575-584.
The Pteridophyte Phylogeny Group (2016), A community-derived classification for extant lycophytes and ferns, in Journal of Systematics and Evolution
, 54(6), 563-603.
Peter Ståhl Joakim Ekman Sture Westerberg Jason R. Grant & Benjamin Dauphin (2016), Mer om pysslinglåsbräken i Sverige, in Svensk Botanisk Tidskrift
, 110(2), 68-74.
Background. The moonwort genus Botrychium of the fern family Ophioglossaceae is composed of diploid and polyploid species that occur in generally cool mountainous regions of the northern and southern hemisphere. Its species are phenotypically variable, and have slight to significant genetic variation within species, between species, or species groups. Consequently there are significant taxonomic problems on a worldwide scale. Speciation and evolutionary processes are largely unknown.General objectives. The proposed project combines phylogeographical and landscape genetic approaches to address a set of questions focusing on speciation processes on local to global scales. This research proposal builds on my knowledge and specimen accessibility in a group that will serve as a promising model of evolution. In particular, this research intends to associate one of the fundamental issues inferring relationships between taxa with key evolutionary processes responsible in adaptation to particular environmental conditions.Specific aims. Where is the center of species richness of Botrychium? Is it the same geographical area that holds the greatest genetic diversity? Have the allopolyploid taxa arisen from a single or multiple origin/event? To what extent are there maternal or paternal preferences in the formation of allopolyploids, and what is the divergence time between them? Finally, what are the spatial genetic structures, and do we have indirect evidence of adaptation to environmental components in diploid B. lunaria populations along their altitudinal ranges (from 800 to 2300 meters)?Experimental design and approaches. The first aim is to produce a new plastid phylogeny based on psbA-trnHGUG, trnLUAA-trnFGAA, and rpL16 regions. Sampling will be concentrated on previously missing species and unsampled geographical areas, especially in Asia. Five specimens of each taxon will be included in the molecular analyses to assess haplotypic diversity within taxa of the same region. The second goal is to reconstruct a nuclear phylogeny to identify parental couples responsible for the formation of the allopolyploids. Subsequently, the comparative analysis between nuclear and plastid phylogenies will allow us to determine the impact of reticulate evolution in the genus and the origin of these taxa following a single or multiple formation in the North hemisphere. The third aim is to distinguish patterns of spatial genetic structures between Swiss populations of Botrychium lunaria in order to infer indirect evidence of local adaptation. Value of the proposed project. For the first time, robust plastid and nuclear phylogenies containing all species with high worldwide representativeness will be generated. I will also attempt to characterize the relationships between polyploids and their diploid progenitors. Using a fern as a model for understanding adaptation to environmental components in populations along altitudinal ranges is a novel approach. The results will be of significant interest to evolutionary biologists, systematic biologists and conservation biologists throughout the world where the genus occurs.