Linked Selection and Gene Density Shape Genome-Wide Patterns of Diversification in Peatmosses.

Genome evolution under speciation is poorly understood in nonmodel and nonvascular plants, such as bryophytes-the largest group of nonvascular land plants. Their genomes are structurally different from angiosperms and likely subjected to stronger linked selection pressure, which may have profound consequences on genome evolution in diversifying lineages, even more so when their genome architecture is conserved. We use the highly diverse, rapidly radiated group of peatmosses () to characterize the processes affecting genome diversification in bryophytes.

Parallel patterns of genetic diversity and structure in circumboreal species of the Sphagnum capillifolium complex.

Premise: Shared geographical patterns of population genetic variation among related species is a powerful means to identify the historical events that drive diversification. The Sphagnum capillifolium complex is a group of closely related peat mosses within the Sphagnum subgenus Acutifolia and contains several circumboreal species whose ranges encompass both glaciated and unglaciated regions across the northern hemisphere. In this paper, we (1) inferred the phylogeny of subg.

Short stories from of rare species, taxonomy, and speciation.

Conserving species and their genetic variation are a global priority to safeguard evolutionary potential in a rapidly changing world. Species are fundamental units in research and nature management, but taxonomic work is increasingly undermined. Increasing knowledge on the species genetic diversity would aid in prioritizing conservation efforts.

A regionally coherent ecological fingerprint of climate change, evidenced from natural history collections.

Climate change has dramatic impacts on ecological systems, affecting a range of ecological factors including phenology, species abundance, diversity, and distribution. The breadth of climate change impacts on ecological systems leads to the occurrence of fingerprints of climate change. However, climate fingerprints are usually identified across broad geographical scales and are potentially influenced by publication biases.

Phylogenomic structure and speciation in an emerging model: the Sphagnum magellanicum complex (Bryophyta).

Sphagnum magellanicum is one of two Sphagnum species for which a reference-quality genome exists to facilitate research in ecological genomics. Phylogenetic and comparative genomic analyses were conducted based on resequencing data from 48 samples and RADseq analyses based on 187 samples. We report herein that there are four clades/species within the S.

Extensive Genome-Wide Phylogenetic Discordance Is Due to Incomplete Lineage Sorting and Not Ongoing Introgression in a Rapidly Radiated Bryophyte Genus.

The relative importance of introgression for diversification has long been a highly disputed topic in speciation research and remains an open question despite the great attention it has received over the past decade. Gene flow leaves traces in the genome similar to those created by incomplete lineage sorting (ILS), and identification and quantification of gene flow in the presence of ILS is challenging and requires knowledge about the true phylogenetic relationship among the species. We use whole nuclear, plastid, and organellar genomes from 12 species in the rapidly radiated, ecologically diverse, actively hybridizing genus of peatmoss (Sphagnum) to reconstruct the species phylogeny and quantify introgression using a suite of phylogenomic methods.

Phylogenetic structure in the Sphagnum recurvum complex (Bryophyta) in relation to taxonomy and geography.

Premise: The Sphagnum recurvum complex comprises a group of closely related peat mosses that are dominant components of many northern wetland ecosystems. Taxonomic hypotheses for the group range from interpreting the whole complex as one polymorphic species to distinguishing 6-10 species. The complex occurs throughout the Northern Hemisphere, and some of the putative species have intercontinental ranges.

Can mowing restore boreal rich-fen vegetation in the face of climate change?

Low-frequency mowing has been proposed to be an effective strategy for the restoration and management of boreal fens after abandonment of traditional haymaking. This study investigates how mowing affects long-term vegetation change in both oceanic and continental boreal rich-fen vegetation. This will allow evaluation of the effectiveness of mowing as a management and restoration tool in this ecosystem in the face of climate change.

Contrasting spatial, temporal and environmental patterns in observation and specimen based species occurrence data.

Species occurrence data records the location and time of an encounter with a species, and is valuable for many aspects of ecological and evolutionary analyses. A key distinction within species occurrence data is between (1) collected and preserved specimens that can be taxonomically validated (i.e.

Divergent evolution and niche differentiation within the common peatmoss Sphagnum magellanicum.

Premise Of The Study: Populations with phenotypic polymorphism in discrete characters may be good models for investigating genome evolution and speciation. Sphagnum magellanicum Brid. is found throughout the northern hemisphere, and despite considerable variation in morphological characters, it is considered one of the least taxonomically controversial peatmoss species.

Spatial Genetic Structure of the Abundant and Widespread Peatmoss Sphagnum magellanicum Brid.

Spore-producing organisms have small dispersal units enabling them to become widespread across continents. However, barriers to gene flow and cryptic speciation may exist. The common, haploid peatmoss Sphagnum magellanicum occurs in both the Northern and Southern hemisphere, and is commonly used as a model in studies of peatland ecology and peatmoss physiology.

Highly overlapping winter diet in two sympatric lemming species revealed by DNA metabarcoding.

Sympatric species are expected to minimize competition by partitioning resources, especially when these are limited. Herbivores inhabiting the High Arctic in winter are a prime example of a situation where food availability is anticipated to be low, and thus reduced diet overlap is expected. We present here the first assessment of diet overlap of high arctic lemmings during winter based on DNA metabarcoding of feces.

Restricted variation in plant barcoding markers limits identification in closely related bryophyte species.

Species-level identification and delimitation of bryophytes using the proposed general barcode markers for land plants has been challenging. Bryophyta (mosses) is the second most species-rich group of land plants after angiosperms, and it is thus of great importance to find useful barcoding regions also for this group of plants. We investigated how the plastid regions atpF-atpH, rbcL and trnH-psbA and the nuclear ITS2 region performed as barcode markers on closely related bryophyte taxa of selected moss (Bartramia, Distichium, Fissidens, Meesia and Syntrichia) and liverwort (Blepharostoma) genera from boreal and arctic regions.

Molecular species delimitation in the Racomitrium canescens complex (Grimmiaceae) and implications for DNA barcoding of species complexes in mosses.

In bryophytes a morphological species concept is still most commonly employed, but delimitation of closely related species based on morphological characters is often difficult. Here we test morphological species circumscriptions in a species complex of the moss genus Racomitrium, the R. canescens complex, based on variable DNA sequence markers from the plastid (rps4-trnT-trnL region) and nuclear (nrITS) genomes.

New environmental metabarcodes for analysing soil DNA: potential for studying past and present ecosystems.

Metabarcoding approaches use total and typically degraded DNA from environmental samples to analyse biotic assemblages and can potentially be carried out for any kinds of organisms in an ecosystem. These analyses rely on specific markers, here called metabarcodes, which should be optimized for taxonomic resolution, minimal bias in amplification of the target organism group and short sequence length. Using bioinformatic tools, we developed metabarcodes for several groups of organisms: fungi, bryophytes, enchytraeids, beetles and birds.

The rare peat moss Sphagnum wulfianum (Sphagnaceae) did not survive the last glacial period in northern European refugia.

Premise Of The Study: Organisms may survive unfavorable conditions either by moving to more favorable areas by means of dispersal or by adapting to stressful environments. Pleistocene glacial periods represent extremely unfavorable conditions for the majority of life forms, especially sessile organisms. Many studies have revealed placements of refugial areas and postglacial colonization patterns of seed plants, but little is still known about areas of long-term survival and historical migration routes of bryophytes.

High genetic diversity in a remote island population system: sans sex.

It has been proposed that long-distance dispersal of mosses to the Hawaiian Islands rarely occurs and that the Hawaiian population of the allopolyploid peat moss Sphagnum palustre probably resulted from a single dispersal event. Here, we used microsatellites to investigate whether the Hawaiian population of the dioicous S. palustre had a single founder and to compare its genetic diversity to that found in populations of S.

North American origin and recent European establishments of the amphi-Atlantic peat moss Sphagnum angermanicum.

Genetic and morphological similarity between populations separated by large distances may be caused by frequent long-distance dispersal or retained ancestral polymorphism. The frequent lack of differentiation between disjunct conspecific moss populations on different continents has traditionally been explained by the latter model, and has been cited as evidence that many or most moss species are extremely ancient and slowly diverging. We have studied intercontinental differentiation in the amphi-Atlantic peat moss Sphagnum angermanicum using 23 microsatellite markers.

Genetic variation and structure in the expanding moss Pogonatum dentatum (Polytrichaceae) in its area of origin and in a recently colonized area.

Genetic variation in the expanding moss species Pogonatum dentatum was studied using intersimple sequence repeat (ISSR) markers. The genetic consequences of range expansion were studied by comparing source populations in a mountain area with populations from a recently colonized lowland area in Sweden. Indices of genetic variation show slightly lower number of alleles per locus in the lowlands and a similar gene diversity in both areas.