The Possible Earliest Allopolyploidization in Tracheophytes Revealed by Phylotranscriptomics and Morphology of Selaginellaceae.

Selaginellaceae, originated in the Carboniferous and survived the Permian-Triassic mass extinction, is the largest family of lycophyte, which is sister to other tracheophytes. It stands out from tracheophytes by exhibiting extraordinary habitat diversity and lacking polyploidization. The organelle genome-based phylogenies confirmed the monophyly of Selaginella, with six or seven subgenera grouped into two superclades, but the phylogenetic positions of the enigmatic Selaginella sanguinolenta clade remained problematic.

The first homosporous lycophyte genome revealed the association between the recent dynamic accumulation of LTR-RTs and genome size variation.

The contrasting genome size between homosporous and heterosporous plants is fascinating. Different from the heterosporous seed plants and mainly homosporous ferns, the lycophytes are either heterosporous (Isoetales and Selaginellales) or homosporous (Lycopodiales). Many lycophytes are the resource plants of Huperzine A (HupA) which is invaluable for treating Alzheimer's disease.

Mitogenome-based phylogenomics provides insights into the positions of the enigmatic sinensis group and the sanguinolenta group in Selaginellaceae (Lycophyte).

Spikemoss (Selaginellaceae) is one of the basal lineages of vascular plants. This family has a single genus Selaginella which consists of about 750 extant species. The phylogeny of Selaginellaceae has been extensively studied mainly based on plastid DNA and a few nuclear sequences.

Plastid Phylogenomics and Plastomic Diversity of the Extant Lycophytes.

Although extant lycophytes represent the most ancient surviving lineage of early vascular plants, their plastomic diversity has long been neglected. The ancient evolutionary history and distinct genetic diversity patterns of the three lycophyte families, each with its own characteristics, provide an ideal opportunity to investigate the interfamilial relationships of lycophytes and their associated patterns of evolution. To compensate for the lack of data on Lycopodiaceae, we sequenced and assembled 14 new plastid genomes (plastomes).

Plastid phylogenomic analyses of the Selaginella sanguinolenta group (Selaginellaceae) reveal conflict signatures resulting from sequence types, outlier genes, and pervasive RNA editing.

Different from the generally conserved plastomes (plastid genomes) of most land plants, the Selaginellaceae plastomes exhibit dynamic structure, high GC content and high substitution rates. Previous plastome analyses identified strong conflict on several clades in Selaginella, however the factors causing the conflictions and the impact on the phylogenetic inference have not been sufficiently investigated. Here, we dissect the distribution of phylogenetic signals and conflicts in Selaginella sanguinolenta group, the plastome of which is DR (direct repeats) structure and with genome-wide RNA editing.

Fire-prone Rhamnaceae with South African affinities in Cretaceous Myanmar amber.

The rapid Cretaceous diversification of flowering plants remains Darwin's 'abominable mystery' despite numerous fossil flowers discovered in recent years. Wildfires were frequent in the Cretaceous and many such early flower fossils are represented by charcoalified fragments, lacking complete delicate structures and surface textures, making their similarity to living forms difficult to discern. Furthermore, scarcity of information about the ecology of early angiosperms makes it difficult to test hypotheses about the drivers of their diversification, including the role of fire in shaping flowering plant evolution.

Ellipinema and ×Ellipisorus? Just Lepisorus (Polypodiaceae)!

The establishment of a segregate lepisoroid fern genus Ellipinema was mainly to accommodate the isolated position of Lepisorus jakonensis (Polypodiaceae) recovered in plastid gene tree. Using newly obtained nuclear data, we recovered that Ellipinema and allied genera, such as Lepidomicrosorium, Lemmaphyllum, Neolepisorus, Paragramma, Tricholepidium and Weatherbya are deeply nested within Lepisorus. The nuclear phylogeny showing incongruent phylogenetic placement in comparison with plastid results perhaps indicated ancient hybridization events.

Distinctive evolutionary pattern of organelle genomes linked to the nuclear genome in Selaginellaceae.

Plastids and mitochondria are endosymbiotic organelles that store genetic information. The genomes of these organelles generally exhibit contrasting patterns regarding genome architecture and genetic content. However, they have similar genetic features in Selaginellaceae, and little is known about what causes parallel evolution.

Backbone phylogeny of Lepisorus (Polypodiaceae) and a novel infrageneric classification based on the total evidence from plastid and morphological data.

The fern genus Lepisorus represents one of the most complicated and controversial lineages in Polypodiaceae, with about 80 species which have been classified into several separate genera, and is notorious for its taxonomic difficulty. Despite progress in recent phylogenetic studies of the family Polypodiaceae involving Lepisorus and its allies, the deep phylogenetic relationship within this group of ferns is still unresolved, and no formal infrageneric classification has been proposed. This contribution presents the most comprehensive phylogenetic analysis of the genus, with 72% species sampled, using a total-evidence approach based on eight plastid markers and ≤25 morphological characters for each species.

Plastome-based phylogenomics resolves the placement of the sanguinolenta group in the spikemoss of lycophyte (Selaginellaceae).

Selaginellaceae have been shown to be monophyletic in previous studies, and include only the single genus Selaginella. However, the two most recent classifications of the genus disagree in terms of the number of subgenera recognized, and the position of problematic clades such as the "sanguinolenta" group, which has been resolved in quite different positions in different studies. Here, we performed a plastid-genome based phylogenomic analysis of Selaginellaceae to address this problem.

The complete chloroplast genome of the , an endangered Pinaceae species in Southern China.

is critically endangered and endemic to Guangxi province of China, with no more than 900 surviving individuals. In this study, we reported the complete chloroplast (cp) genome of . The complete chloroplast genome is 121897 bp in size.

Correction to: Directed Repeats Co-occur with Few Short-Dispersed Repeats in Plastid Genome of a Spikemoss, Selaginella vardei (Selaginellaceae, Lycopodiopsida).

Following the publication of this article [1], the authors reported that the Fig. 2 described in the article had a mistake that two grey blocks in S. moellendorffii was not placed as background color, and in the Fig.

Directed Repeats Co-occur with Few Short-Dispersed Repeats in Plastid Genome of a Spikemoss, Selaginella vardei (Selaginellaceae, Lycopodiopsida).

Background: It is hypothesized that the highly conserved inverted repeats (IR) structure of land plant plastid genomes (plastomes) is beneficial for stabilizing plastome organization, whereas the mechanism of the occurrence and stability maintenance of the recently reported direct repeats (DR) structure is yet awaiting further exploration. Here we describe the DR structure of the Selaginella vardei (Selaginellaceae) plastome, to elucidate the mechanism of DR occurrence and stability maintenance.

Results: The plastome of S.

The Unique Evolutionary Trajectory and Dynamic Conformations of DR and IR/DR-Coexisting Plastomes of the Early Vascular Plant Selaginellaceae (Lycophyte).

Both direct repeats (DR) and inverted repeats (IR) are documented in the published plastomes of Selaginella species indicating the unusual and diverse plastome structure in the family Selaginellaceae. In this study, we newly sequenced complete plastomes of seven species from five main lineages of Selaginellaceae and also resequenced three species (Selaginella tamariscina, Selaginella uncinata, and Selaginella moellendorffii) to explore the evolutionary trajectory of Selaginellaceae plastomes. Our results showed that the plastomes of Selaginellaceae vary remarkably in size, gene contents, gene order, and GC contents.

Plastid Phylogenomics Resolve Deep Relationships among Eupolypod II Ferns with Rapid Radiation and Rate Heterogeneity.

The eupolypods II ferns represent a classic case of evolutionary radiation and, simultaneously, exhibit high substitution rate heterogeneity. These factors have been proposed to contribute to the contentious resolutions among clades within this fern group in multilocus phylogenetic studies. We investigated the deep phylogenetic relationships of eupolypod II ferns by sampling all major families and using 40 plastid genomes, or plastomes, of which 33 were newly sequenced with next-generation sequencing technology.

Elevation Shift in Mill. (Pinaceae) of Subtropical and Temperate China and Vietnam-Corroborative Evidence from Cytoplasmic DNA and Ecological Niche Modeling.

The "elevational shift" scenario has been proposed as a model to explain the response of cold-adapted organisms to Quaternary climatic fluctuations in Europe and North America. However, the elevational shift model has not been well-explored in eastern Asia, which is more topographically complex than the other Northern Hemisphere biogeographic regions. Here, we evaluated the role of elevational shift in the closely related firs, or Mill.

Isolation and characterization of microsatellite markers in the complex (Polypodiaceae).

Premise Of The Study: Microsatellites were designed and characterized in the Sino-Himalayan fern complex (Polypodiaceae) to further study the phylogeography and reproductive ecology of this species.

Methods And Results: From a genomic library obtained by next-generation sequencing, 10 polymorphic and six monomorphic microsatellite loci were developed. In one population of from Taibaishan in central China, the number of alleles observed for these microsatellites ranged from seven to 29, and observed and expected heterozygosity ranged from 0.

Molecular Phylogeny of the Cliff Ferns (Woodsiaceae: Polypodiales) with a Proposed Infrageneric Classification.

The cliff fern family Woodsiaceae has experienced frequent taxonomic changes at the familial and generic ranks since its establishment. The bulk of its species were placed in Woodsia, while Cheilanthopsis, Hymenocystis, Physematium, and Protowoodsia are segregates recognized by some authors. Phylogenetic relationships among the genera of Woodsiaceae remain unclear because of the extreme morphological diversity and inadequate taxon sampling in phylogenetic studies to date.

Phylogenetic relationships, possible ancient hybridization, and biogeographic history of Abies (Pinaceae) based on data from nuclear, plastid, and mitochondrial genomes.

Abies, the second largest genus of Pinaceae, consists of approximately 48 species occurring in the north temperate region. Previous molecular phylogenetic studies improved our understanding of relationships within the genus, but were limited by relying on only DNA sequence data from single genome and low taxonomic sampling. Here we use DNA data from three genomes (sequences of internal transcribed spacer of nrITS, three chloroplast DNA intergenic spacers, and two mitochondrial intergenic spacers) from 42 species to elucidate species relationships and construct the biogeographic history of Abies.

The rise of the Himalaya enforced the diversification of SE Asian ferns by altering the monsoon regimes.

Background: The rise of high mountain chains is widely seen as one of the factors driving rapid diversification of land plants and the formation of biodiversity hotspots. Supporting evidence was reported for the impact of the rapid rise of the Andean mountains but this hypothesis has so far been less explored for the impact of the "roof of the world". The formation of the Himalaya, and especially the rise of the Qinghai-Tibetan Plateau in the recent 20 million years, altered the monsoon regimes that dominate the current climates of South East Asia.

Indehiscent sporangia enable the accumulation of local fern diversity at the Qinghai-Tibetan Plateau.

Background: Indehiscent sporangia are reported for only a few of derived leptosporangiate ferns. Their evolution has been likely caused by conditions in which promotion of self-fertilization is an evolutionary advantageous strategy such as the colonization of isolated regions and responds to stressful habitat conditions. The Lepisorus clathratus complex provides the opportunity to test this hypothesis because these derived ferns include specimens with regular dehiscent and irregular indehiscent sporangia.

Phylogeography of the Sino-Himalayan fern Lepisorus clathratus on "the roof of the world".

Background: The Qinghai-Tibetan Plateau (QTP) and its southern and southeastern mountain ranges, Himalaya-Hengduan Mountains (HHM), are one of the most extensive habitats for alpine plants in the world. How ferns occurring in QTP and HHM changed their distribution ranges in response to Quaternary climatic oscillations remains almost unknown.

Methodology And Results: We employed sequences of two chloroplast DNA regions, rps4-trnS and trnL-trnF, to reconstruct phylogeography of the Sino-Himalayan fern Lepisorus clathratus, occurring mainly in the QTP and HHM.

Phylogeny of the paleotropical fern genus Lepisorus (Polypodiaceae, Polypodiopsida) inferred from four chloroplast DNA regions.

Phylogenetic relationships within the paleotropical genus Lepisorus (Polypodiaceae) were investigated using plastid DNA sequences from four regions: rbcL, rps4 and rps4-trnS IGS, trnL intron plus trnL-F IGS, rbcL-atpB IGS. Over 4000 nucleotides were sequenced for 77 specimens belonging to 54 species. Each cpDNA region was analyzed separately and combined into a single dataset.