Alkylation Repair Homolog 5 Regulates N(6)-methyladenosine (m6A) Methylation of Mitsugumin 53 to Attenuate Myocardial Infarction by Inhibiting Apoptosis and Oxidative Stress.

ABSTRACT: N(6)-methyladenosine (m6A) methylation modification is involved in the progression of myocardial infarction (MI). In this study, we investigated the effects of demethylase alkylation repair homolog 5 (ALKBH5) on cell apoptosis and oxidative stress in MI. The ischemia/reperfusion (I/R) injury mouse model and hypoxia/reoxygenation (H/R) cell model were established. The levels of ALKBH5 and mitsugumin 53 (MG53) were measured by quantitative real-time polymerase chain reaction, immunohistochemical, and immunofluorescence analysis. Apoptosis was evaluated by TUNEL assay, flow cytometry, and western blot. Oxidative stress was assessed by antioxidant index kits. Methylation was analyzed by RNA binding protein immunoprecipitation (RIP), MeRIP, and dual-luciferase reporter assay. We observed that ALKBH5 and MG53 were highly expressed in MI. Overexpression of ALKBH5 inhibited H/R-induced cardiomyocyte apoptosis and oxidative stress in vitro, and it inhibited I/R-induced collagen deposition, cardiac function, and apoptosis in vivo. ALKBH5 could bind to MG53, inhibit m6A methylation of MG53, and increase its mRNA stability. Silencing of MG53 counteracted the inhibition of apoptosis and oxidative stress induced by ALKBH5. In conclusion, ALKBH5 suppressed m6A methylation of MG53 and inhibited MG53 degradation to inhibit apoptosis and oxidative stress of cardiomyocytes, thereby attenuating MI. The results provided a theoretical basis that ALKBH5 is a potential target for MI treatment.

Accumulation, translocation, and fractionation of rare earth elements (REEs) in fern species of hyperaccumulators and non-hyperaccumulators growing in urban areas.

The issue of ion-adsorption type rare earth deposits (IADs) in urban areas of South China has garnered significant attention due to its environmental implications. Hyperaccumulator-based phytoremediation is a potentially effective solution for reducing the environmental impact of IADs in urban areas, particularly using ferns as they are known to be REE hyperaccumulators. However, the ability of different fern species to accumulate REEs in urban areas remains unknown. In this study, four fern species, including known hyperaccumulators (Dicranopteris linearis and Blechnum orientale) and other ferns (Pteris ensiformis and Cibotium barometz), were studied to investigate their REE accumulation abilities in the Guangzhou urban area. The aboveground parts of Dicranopteris linearis (848.7 µg g-1) and Blechum orientale (1046.8 µg g-1) have been found to accumulate high concentrations of REEs, demonstrating they probably can be applied for phytoremediation in the natural environments. Despite having lower REE concentrations than REE hyperaccumulators, Pteris ensiformis and Cibotium barometz still probably have the function as phytostabilizers in urban areas, as REEs can be enriched in their roots beyond the normal levels of plants. The enrichment of REEs in ferns is influenced by the availability of various nutrients (K, Ca, Fe, and P), which probably can be associated with different growth processes. The four fern species show LREE enrichment, moderate Eu anomalies and different Ce anomalies. It is difficult to absorb and transfer Ce to the aboveground parts of Blechnum orientale and Cibotium barometz. The study also identified selective enrichment of Ce in Pteris ensiformis, which has potential for comprehensive extraction of REEs when combined with other REE hyperaccumulators. REE fractionations are probably determined by the specific characteristics of different fern parts. Overall, these findings provide insights for addressing potential environmental problems related to IADs and offer guidelines for phytoremediation technology in addressing high REE levels in urban areas.

Genome-wide data reveal cryptic diversity and hybridization in a group of tree ferns.

Discovery of cryptic diversity is essential to understanding both the process of speciation and the conservation of species. Determining species boundaries in fern lineages represents a major challenge due to lack of morphologically diagnostic characters and frequent hybridization. Genomic data has substantially enhanced our understanding of the speciation process, increased the resolution of species delimitation studies, and led to the discovery of cryptic diversity. Here, we employed restriction-site-associated DNA sequencing (RAD-seq) and integrated phylogenomic and population genomic analyses to investigate phylogenetic relationships and evolutionary history of 16 tree ferns with marginate scales (Cyatheaceae) from China and Vietnam. We conducted multiple species delimitation analyses using the multispecies coalescent (MSC) model and novel approaches based on genealogical divergence index (gdi) and isolation by distance (IBD). In addition, we inferred species trees using concatenation and several coalescent-based methods, and assessed hybridization patterns and rate of gene flow across the phylogeny. We obtained highly supported and generally congruent phylogenies inferred from concatenated and summary-coalescent methods, and the monophyly of all currently recognized species were strongly supported. Our results revealed substantial evidence of cryptic diversity in three widely distributed Gymnosphaera species, each of which was composite of two highly structure lineages that may correspond to cryptic species. We found that hybridization was fairly common between not only closely related species, but also distantly related species. Collectively, it appears that scaly tree ferns may contain cryptic diversity and hybridization has played an important role throughout the evolutionary history of this group.

Research status and development trend of extracorporeal membrane oxygenation based on bibliometrics.

Background: Using bibliometric method to analyze the research status and development trend of extracorporeal membrane oxygenation (ECMO), we aim to provide clinicians, scientists, and stakeholders with the most up-to-date and comprehensive overview of ECMO research. Materials and methods: Using Excel and VOSviewer, the literature on ECMO was systematically analyzed regarding publication trends, journal source, foundation, countries, institutions, core authors, research hotspots, and market distribution. Results: There were five important time nodes in the research process of ECMO, including the success of the first ECMO operation, the establishment of ELSO, and the outbreak of influenza A/H1N1 and COVID-19. The R&D centers of ECMO were the United States, Germany, Japan, and Italy, and the attention to ECMO was gradually increasing in China. The products most used in the literature were from Maquet, Medtronic, and LivaNova. Medicine enterprises attached great importance to the funding of ECMO research. In recent years, the literature has mainly focused on the following aspects: the treatment of ARDS, the prevention of coagulation system-related complications, the application in neonatal and pediatric patients, mechanical circulatory support for cardiogenic shock, and ECPR and ECMO during the COVID-19 pandemic. Conclusion: The frequent epidemic occurrence of viral pneumonia and the technical advancement of ECMO in recent years have caused an increase in clinical applications. The hot spots of ECMO research are shown in the treatment of ARDS, mechanical circulatory support for cardiogenic shock, and the application during the COVID-19 pandemic.

Ventricular arrhythmia and sudden cardiac death in hypertrophic cardiomyopathy: From bench to bedside.

Patients with hypertrophic cardiomyopathy (HCM) mostly experience minimal symptoms throughout their lifetime, and some individuals have an increased risk of ventricular arrhythmias and sudden cardiac death (SCD). How to identify patients with a higher risk of ventricular arrythmias and SCD is the priority in HCM research. The American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) both recommend the use of risk algorithms to identify patients at high risk of ventricular arrhythmias, to be selected for implantation of implantable cardioverters/defibrillators (ICDs) for primary prevention of SCD, although major discrepancies exist. The present SCD risk scoring systems cannot accurately identify early-stage HCM patients with modest structural remodeling and mild disease manifestations. Unfortunately, SCD events could occur in young asymptomatic HCM patients and even as initial symptoms, prompting the determination of new risk factors for SCD. This review summarizes the studies based on patients' surgical specimens, transgenic animals, and patient-derived induced pluripotent stem cells (hiPSCs) to explore the possible molecular mechanism of ventricular arrhythmia and SCD. Ion channel remodeling, Ca2+ homeostasis abnormalities, and increased myofilament Ca2+ sensitivity may contribute to changes in action potential duration (APD), reentry circuit formation, and trigger activities, such as early aferdepolarization (EAD) or delayed afterdepolarization (DAD), leading to ventricular arrhythmia in HCM. Besides the ICD implantation, novel drugs represented by the late sodium current channel inhibitor and myosin inhibitor also shed light on the prevention of HCM-related arrhythmias. The ideal prevention strategy of SCD in early-stage HCM patients needs to be combined with gene screening, hiPSC-CM testing, machine learning, and advanced ECG studies, thus achieving individualized SCD prevention.

Tectariadanangensis (Tectariaceae), a new fern species from Vietnam.

A new fern species, Tectariadanangensis (Tectariaceae) from Vietnam, which had long been misreported as T.crenata, is described and illustrated. The new species resembles T.poilanei, a species long neglected in the fern flora of Indochina, in the frond shape and sori arrangement, but differs by its irregularly 2-rowed sori (versus regularly 2-rowed, distantly and evenly arranged) between lateral veins of pinnae, fronds being more or less dimorphic (versus monomorphic) and basal pinnae each with a base-joined (versus free) lobe. Phylogenetic analyses of five plastid regions (atpB, ndhF + ndhF-trnN, rbcL, rps16-matK + matK and trnL-F) suggested T.danangensis has a close affinity to T.harlandii. Tectariadanangensis appears to be an intermediate species between T.harlandii and T.poilanei.

A phylogenetic and morphological study of the Tectariafuscipes group (Tectariaceae), with description of a new species.

The fern species Tectariafuscipes and morphologically similar species, which are common in tropical and subtropical mainland Asia, constitute a taxonomically confusing group. To better understand species boundaries and relationships within the T.fuscipes group, we conducted phylogenetic analyses of five plastid regions and morphological observations of herbarium specimens and living plants. As a result, we produced a generally well-resolved phylogeny of the T.fuscipes group and related species in Asia. The phylogenetic analyses supported the monophyly of the T.fuscipes group, which includes T.dissecta, T.fuscipes, T.ingens, T.paradoxa, T.setulosa, T.subfuscipes, T.subsageniacea and a new species, but excludes T.kusukusensis. However, T.fuscipes, T.subfuscipes and T.subsageniacea are almost indistinguishable in morphology, which form a complex characterised by the black linear-lanceolate stipe scales. The new species found in southern China and Vietnam is described here as T.fungii. It is similar to the T.fuscipes complex and T.kusukusensis, but differs from the former mainly by its brown-castaneous lanceolate stipe scales and from the latter by having nearly hairless laminae (versus frond axes abaxially bearing copious hairs).

Perioperative safety of simultaneous off-pump coronary artery bypass grafting with non-cardiac surgery of moderate-to-severe severity.

BACKGROUND: To evaluate the perioperative safety of simultaneous off-pump coronary artery bypass grafting (OPCABG) with non-cardiac surgery. METHODS: From September 2013 to January 2019, patients who underwent OPCABG surgery in the Department of Cardiology, Peking University First Hospital were included in this retrospective study. A total of 54 patients who underwent simultaneous surgery were defined as simultaneous surgery group. A total of 108 patients who had recently undergone isolated OPCABG surgery, and had similar vascular reconstruction methods were selected for matching, and these patients were defined as the OPCABG group. The general data and laboratory indicators were detected and were used as baseline data, and the EuroSCORE II scoring system was used to evaluate the surgical risk of patients based on these data. During surgery, intraoperative indicators were assessed and evaluated during surgery. In addition, evaluation of postoperative indicators was performed, including mechanical ventilation time, residence time in ICU, and proportion of perioperative myocardial infarction, perioperative stroke, postoperative renal failure, and surgical wound infection. RESULTS: All the combined non-cardiac surgeries were assessed to be of moderate-to-severe grade by operative severity scoring system. The analysis of intraoperative indicators showed that there were no significant differences in proportion of emergency or urgent surgery, cases of arterial and venous anastomosis, and proportion of intraoperative blood transfusion between two groups (P > 0.05). Meanwhile, the values of operation time and intraoperative blood loss of patients in simultaneous surgery group were significantly higher than that in OPCABG group (P < 0.05). No perioperative death events occurred in this study. In terms of postoperative indicators, the values of operation duration and intraoperative blood loss of patients in simultaneous surgery group were significantly higher than that in OPCABG group (P < 0.05). CONCLUSIONS: Simultaneous OPCABG surgery with non-cardiac surgeries of moderate-to-severe severity may not be associated with increased postoperative risks when compared with isolated OPCABG.

Allopolyploid Speciation Accompanied by Gene Flow in a Tree Fern.

Hybridization in plants may result in hybrid speciation or introgression and, thus, is now widely understood to be an important mechanism of species diversity on an evolutionary timescale. Hybridization is particularly common in ferns, as is polyploidy, which often results from hybrid crosses. Nevertheless, hybrid speciation as an evolutionary process in fern lineages remains poorly understood. Here, we employ flow cytometry, phylogeny, genomewide single nucleotide polymorphism data sets, and admixture and coalescent modeling to show that the scaly tree fern, Gymnosphaera metteniana is a naturally occurring allotetraploid species derived from hybridization between the diploids, G. denticulata and G. gigantea. Moreover, we detected ongoing gene flow between the hybrid species and its progenitors, and we found that G. gigantea and G. metteniana inhabit distinct niches, whereas climatic niches of G. denticulata and G. metteniana largely overlap. Taken together, these results suggest that either some degree of intrinsic genetic isolation between the hybrid species and its parental progenitors or ecological isolation over short distances may be playing an important role in the evolution of reproductive barriers. Historical climate change may have facilitated the origin of G. metteniana, with the timing of hybridization coinciding with a period of intensification of the East Asian monsoon during the Pliocene and Pleistocene periods in southern China. Our study of allotetraploid G. metteniana represents the first genomic-level documentation of hybrid speciation in scaly tree ferns and, thus, provides a new perspective on evolution in the lineage.

Bolbitis lianhuachihensis (Dryopteridaceae), a new species from Taiwan.

A new species of Bolbitis, B. lianhuachihensis sp. nov., was found in central Taiwan. It most resembles B. virens var. compacta and B. hainanensis. A phylogenetic tree of Taiwanese and other Asian species of Bolbitis species supports the recognition of the new species. Morphologically, the combination of anastomosing venation and fewer sterile pinnae are critical characters to discriminate B. lianhuachihensis from other Taiwanese Bolbitis species. Bolbitis lianhuachihensis can be further distinguished from B. virens var. compacta and B. hainanensis by having lanceolate sterile pinnae and absent or fewer free veinlets in small areoles of sterile pinnae. The morphological descriptions, illustration, ecology and distribution of the new species are presented. A key to all Taiwanese Bolbitis is also provided.

Nuclear loci developed from multiple transcriptomes yield high resolution in phylogeny of scaly tree ferns (Cyatheaceae) from China and Vietnam.

The scaly tree ferns, Cyatheaceae, form a large natural group of ca. 640 species. They comprise an ideal model for studying the biogeography of plants due to their broad distribution across the tropical to south-temperate areas of the world. However, tracing the biogeographic history of this highly diversified group has been hampered by unresolved evolutionary relationships among the major clades. Here, we generated transcriptome sequences of five species in three genera of Cyatheaceae (Alsophila, Gymnosphaera, and Sphaeropteris) and used them to search for single-copy nuclear loci for phylogenetic reconstruction. We identified a total of 818 candidate single-copy loci across multiple Cyatheaceae species. To test their phylogenetic utility, we further obtained sequence data of 12 of these loci for 76 samples representing all 13 known species of scaly tree ferns in China and Vietnam. Phylogenetic analyses based on multispecies coalescent and, alternatively, concatenation models yielded congruent results with high resolution. Additionally, we used the 12 loci to identify genetic signals of hybridization. Overall, our results demonstrated that multiple, single-copy loci are informative and efficient tools for phylogenetic or evolutionary studies of scaly tree ferns.

New Species of the Fern Genus Lindsaea (Lindsaeaceae) from New Guinea with Notes on the Phylogeny of L. sect. Synaphlebium.

To determine the taxonomic identities and the systematic positions of some collections of Lindsaea sect. Synaphlebium (Lindsaeaceae) from Papua New Guinea, we conducted morphological comparisons and phylogenetic analyses on the whole section. A total of 22 morphological characters were selected and coded for each of all known taxa in L. sect. Synaphlebium, and were analyzed using maximum parsimony. The datasets containing either of or combined two plastid DNA sequences (trnL-trnF spacer and trnH-psbA spacer) of 37 taxa were analyzed using maximum parsimony, maximum likelihood, and Bayesian inference. Morphological comparisons revealed two new species which are formally published here as L. subobscura and L. novoguineensis. Lindsaea subobscura is similar to sympatric L. obscura and L. modesta but differs in the obviously reduced upper pinnules and other characters. Lindsaea novoguineensis is most similar to L. pacifica from Melanesia but differs in having rhomboid pinnules with truncate apices and concave soral receptacles. Molecular analyses resolved L. sect. Synaphlebium and allied species into five well-supported clades, namely L. rigida clade, L. obtusa clade, L. pulchella clade, L. multisora clade, and L. cultrata clade. The new species L. novoguineensis is included in L. obtusa clade; L. subobscura is in L. pulchella clade; whereas the majority of L. sect. Synaphlebium is clustered in L. cultrata clade. As the section Synaphlebium sensu Kramer is strongly suggested as polyphyletic, we propose the concept of a monophyletic L. sect. Synaphlebium in a broad sense that comprises five lineages. The morphological circumscription of L. sect. Synaphlebium sensu lato and the divergence in morphology, habit, and distribution between the five lineages are briefly discussed. Further molecular study is needed to test the systematic positions of 16 other species which are supposed to be within L. sect. Synaphlebium sensu lato but have not been included in this and previous molecular analyses.

Phylogeny and character evolution of the fern genus Tectaria (Tectariaceae) in the Old World inferred from chloroplast DNA sequences.

In this study we provide a phylogeny for the pantropical fern genus Tectaria, with emphasis on the Old World species, based on sequences of five plastid regions (atpB, ndhF plus ndhF-trnL, rbcL, rps16-matK plus matK, and trnL-F). Maximum parsimony, maximum likelihood, and Bayesian inference are used to analyze 115 individuals, representing ca. 56 species of Tectaria s.l. and 36 species of ten related genera. The results strongly support the monophyly of Tectaria in a broad sense, in which Ctenitopsis, Hemigramma, Heterogonium, Psomiocarpa, Quercifilix, Stenosemia, and Tectaridium should be submerged. Such broadly circumscribed Tectaria is supported by the arising pattern of veinlets and the base chromosome number (x=40). Four primary clades are well resolved within Tectaria, one from the Neotropic (T. trifoliata clade) and three from the Old World (T. subtriphylla clade, Ctenitopsis clade, and T. crenata clade). Tectaria crenata clade is the largest one including six subclades. Of the genera previously recognized as tectarioid ferns, Ctenitis, Lastreopsis, and Pleocnemia, are confirmed to be members in Dryopteridaceae; while Pteridrys and Triplophyllum are supported in Tectariaceae. To infer morphological evolution, 13 commonly used characters are optimized on the resulting phylogenetic trees and in result, are all homoplastic in Tectaria.

[Peri-operative management and follow-up outcomes of cardiac surgery in dialysis-dependent patients with end stage renal disease].

OBJECTIVE: To summarize the perioperative management experience of patients with end-stage renal diseases (ESRD) undergoing cardiac surgery and the follow-up outcomes. METHODS: From September 2004 to February 2012, 18 dialysis-dependent patients with ESRD received cardiac surgery in Department of Cardiac Surgery, Peking University First Hospital. A series of methods were employed to maintain water-electrolyte and acid-base balance and coagulation function. We followed up the patients by clinic service or telephone. RESULTS: The spectra of surgical interventions included isolated coronary artery bypass graft (CABG, n=13), isolated valve replacement (VR, n=2) and concomitant CABG and VR (n=3). Of the 18 patients, 3 died within the Peri-operative period and 15 recovered and were discharged. The follow up period was 6-91 months [(27.6±27.5) months]. Within the follow up period, 2 patients died (66th month and 76th month), non-fatal complications occurred in 3 patients. Cardiac functions of the survived patients were good according to the New York Heart Association (NYHA) classification, 4 of them were within NYHA class I and 9 within NYHA class II. CONCLUSION: Dialysis-dependent patients with end-stage renal diseases are a high risk group receiving cardiac surgery, but a comprehensive Peri-operative management of water-electrolyte and acid-base balance and coagulation function could yield a better outcome.

Molecular circumscription and major evolutionary lineages of the fern genus Dryopteris (Dryopteridaceae).

BACKGROUND: The fern genus Dryopteris (Dryopteridaceae) is among the most common and species rich fern genera in temperate forests in the northern hemisphere containing 225-300 species worldwide. The circumscription of Dryopteris has been controversial and various related genera have, over the time, been included in and excluded from Dryopteris. The infrageneric phylogeny has largely remained unclear, and the placement of the majority of the supraspecific taxa of Dryopteris has never been tested using molecular data. RESULTS: In this study, DNA sequences of four plastid loci (rbcL gene, rps4-trnS spacer, trnL intron, trnL-F spacer) were used to reconstruct the phylogeny of Dryopteris. A total of 122 accessions are sampled in our analysis and they represent 100 species of the expanded Dryopteris including Acrophorus, Acrorumohra, Diacalpe, Dryopsis, Nothoperanema, and Peranema. All four subgenera and 19 sections currently recognized in Dryopteris s.s. are included. One species each of Arachniodes, Leptorumohra, and Lithostegia of Dryopteridaceae are used as outgroups. Our study confirms the paraphyly of Dryopteris and provides the first strong molecular evidence on the monophyly of Acrophorus, Diacalpe, Dryopsis, Nothoperanema, and Peranema. However, all these monophyletic groups together with the paraphyletic Acrorumohra are suggested to be merged into Dryopteris based on both molecular and morphological evidence. Our analysis identified 13 well-supported monophyletic groups. Each of the 13 clades is additionally supported by morphological synapomophies and is inferred to represent a major evolutionary lineage in Dryopteris. In contrast, monophyly of the four subgenera and 15 out of 19 sections currently recognized in Dryopteris s.s is not supported by plastid data. CONCLUSIONS: The genera, Acrophorus, Acrorumohra, Diacalpe, Dryopsis, Nothoperanema, and Peranema, should all be merged into Dryopteris. Most species of these genera share a short rhizome and catadromic arrangement of frond segments, unlike the sister genus of Dryopteris s.l., Arachniodes, which has anadromic arrangement of frond segments. The non-monophyly of the 19 out of the 21 supraspecific taxa (sections, subgenera) in Dryopteris strongly suggests that the current taxonomy of this genus is in need of revision. The disagreement between the previous taxonomy and molecular results in Dryopteris may be due partly to interspecific hybridization and polyplodization. More morphological studies and molecular data, especially from the nuclear genome, are needed to thoroughly elucidate the evolutionary history of Dryopteris. The 13 well-supported clades identified based on our data represent 13 major evolutionary lineages in Dryopteris that are also supported by morphological synapomophies.

Detection of perioperative myocardial infarction with ischemia-modified albumin.

We assessed the perioperative pattern of serum ischemia-modified albumin and its role as a myocardial ischemia indicator for early detection of perioperative myocardial infarction in patients undergoing off-pump coronary artery bypass grafting. Venous blood samples were collected from 63 consecutive patients before the operation, immediately after the operation, and at 3, 6, 12, and 24 h postoperatively. Serum ischemia-modified albumin levels were analyzed using an albumin cobalt binding test. The patients were divided into 2 groups retrospectively, according to the occurrence of perioperative myocardial infarction. The serum ischemia-modified albumin levels were compared between groups. The levels peaked immediately after the operation, followed by a gradual regression, but remained elevated during the first 24 h in all patients. The occurrence of perioperative myocardial infarction was identified in 10 patients who had significantly higher ischemia-modified albumin levels at 3 h postoperatively and slower regression rates. Perioperative serum ischemia-modified albumin levels might be helpful in predicting perioperative myocardial infarction.

Extreme multiple reticulate origins of the Pteris cadieri complex (Pteridaceae).

The Pteris cadieri complex displays extensive morphological variation and seems to have originated through hybridization. However, the members of this complex reproduce by apogamy, which usually limits genetic variation. To evaluate the hypotheses of hybrid origins, the pattern of evolution in this species complex is reconstructed. Multiple methodologies were used. Diploids, triploids, and tetraploids were identified by chromosome counts and flow cytometry. Nuclear DNA markers (cytosolic phosphoglucose isomerase gene, PgiC) were used, together with chloroplast DNA markers (atpB-rbcL spacer and rbcL gene) to infer the biparental and maternal lineages of the Pteris cadieri complex. The three cpDNA haplotype groups and five PgiC alleles found in this study indicate that the evolution of the Pteris cadieri complex has been extremely reticulate. Up to 11 taxa belonging to eight morphs were identified. By comparing genetic variation in the Pteris cadieri in two independent areas, Hainan and Taiwan, we inferred that hybridization has occurred independently in different areas. Furthermore, we found evidence for phenological divergence (evergreen and deciduous) within Taiwan. We propose that the Pteris cadieri complex originated from different genetic lineages through multiple hybridizations in different geographical areas, leading to its present morphological diversity.

Polyphyly of the fern family Tectariaceae sensu Ching: insights from cpDNA sequence data.

Tectariaceae are a pantropical fern family of about 20 genera, among which 8 are distributed in China. The morphological distinctiveness of the family is widely recognized, yet relatively little systematic research has been conducted on members of Tectariaceae. Phylogenetic analyses of chloroplast DNA sequence data (rbcL and atpB) from 15 species representing all 8 genera in China were carried out under parsimony criteria and Bayesian inference. The phylogenetic reconstructions indicated that the fern family Tectariaceae as traditionally circumscribed are polyphyletic. Ctenitis, Dryopsis, Lastreopsis clustered with and should be included within the newly-defined Dryopteridaceae, and Pleocnemia is also tentatively assigned to it. A narrowly monophyletic Tectariaceae is identified, which includes Ctenitopsis, Hemigramma, Pteridrys, Quercifilix, and Tectaria. In the single rbcL analysis, Arthropteris clustered with the above-mentioned monophyletic Tectariaceae. Although further investigations are still needed to identify infrafamilial relationships within the monophyletic Tectariaceae and to redefine several problematic genera, we propose a working concept here that better reflects the inferred evolutionary history of this group.