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Premise: Apomixis in ferns is relatively common and obligatory. Sterile hybrids may restore fertility via apomixis at a cost of long‐term genetic stagnation. In this study, we outlined apomixis as a possible temporary phase leading to sexuality and analyzed factors relating to transitioning to and away from apomixis, such as unreduced and reduced spore formation in apomict and apo‐sex hybrid ferns. Methods: We analyzed the genome size of 15 fern species or hybrids ("taxa") via flow cytometry. The number of reduced and unreduced gametophytes was established as a proxy for viable spore formation of either type. We also calculated the spore abortion ratio (sign of reduced spores) in several taxa, including the apo‐sex hybrid Dryopteris × critica and its 16 apomictically formed offspring. Results: Four of 15 sampled taxa yielded offspring variable in genome size. Specifically, each variable taxon formed one viable reduced plant among 12–451 sampled gametophytes per taxon. Thus, haploid spore formation in the studied apomicts was very rare but possible. Spore abortion analyses indicated gradually decreasing abortion (haploid spore formation) over time. In Dryopteris × critica, abortion decreased from 93.8% to mean 89.5% in one generation. Conclusions: Our results support apomixis as a transitionary phase toward sexuality. Newly formed apomicts hybridize with sexual relatives and continue to form haploid spores early on. Thus, they may get the genomic content necessary for regular meiosis and restore sexuality. If the missing relative goes extinct, the lineage gets locked into apomixis as may be the case with the Dryopteris affinis complex. [ABSTRACT FROM AUTHOR]

Polypodium paleaceum Borkh. has appeared in the literature as a name not related to a well-defined species and its type specimen, a plant from Gärtner's garden, in Calw (Germany), does not exist anymore. Our study of Borkhausen's protologue leads us to think that it is likely to be a Dryopteris. A neotype, based on Dryopteris filix-mas, with material collected in 2023 in the same area in Germany where Gärtner's plant was believed to have been collected, is designated. [ABSTRACT FROM AUTHOR]

Abstract Most drugs used in the treatment of helminthiasis in humans and animals have lost their efficacy due to the development of drug-resistance in helminths. Moreover, since anthelmintics, like many pharmaceuticals, are now recognized as hazardous contaminants of the environment, returning to medicinal plants and their products represents an environmentally friendly way to treat helminthiasis. The goal of the present study was to test the anthelminthic activity of methanol extracts of eight selected European ferns from the genera Dryopteris, Athyrium and Blechnum against the nematode Haemonchus contortus, a widespread parasite of small ruminants. Eggs and adults of H. contortus drug-susceptible strain ISE and drug-resistant strain WR were isolated from experimentally infected sheep. The efficacy of fern extracts was assayed using egg hatch test and adults viability test based on ATP-level measurement. Among the ferns tested, only Dryopteris aemula extract (0.2 mg/mL) inhibited eggs hatching by 25% in comparison to control. Athyrium distentifolium, Dryopteris aemula and Dryopteris cambrensis were effective against H. contortus adults. In concentration 0.1 mg/mL, A. distentifolium, D. aemula, D. cambrensis significantly decreased the viability of females from ISE and WR strains to 36.2%, 51.9%, 32.9% and to 35.3%, 27.0%, 23.3%, respectively in comparison to untreated controls. None of the extracts exhibited toxicity in precise cut slices from ovine liver. Polyphenol’s analysis identified quercetin, kaempferol, luteolin, 3-hydroxybenzoic acid, caffeic acid, coumaric acid and protocatechuic acid as the major components of these anthelmintically active ferns.

Most drugs used in the treatment of helminthiasis in humans and animals have lost their efficacy due to the development of drug-resistance in helminths. Moreover, since anthelmintics, like many pharmaceuticals, are now recognized as hazardous contaminants of the environment, returning to medicinal plants and their products represents an environmentally friendly way to treat helminthiasis. The goal of the present study was to test the anthelminthic activity of methanol extracts of eight selected European ferns from the genera Dryopteris, Athyrium and Blechnum against the nematode Haemonchus contortus, a widespread parasite of small ruminants. Eggs and adults of H. contortus drug-susceptible strain ISE and drug-resistant strain WR were isolated from experimentally infected sheep. The efficacy of fern extracts was assayed using egg hatch test and adults viability test based on ATP-level measurement. Among the ferns tested, only Dryopteris aemula extract (0.2 mg/mL) inhibited eggs hatching by 25% in comparison to control. Athyrium distentifolium, Dryopteris aemula and Dryopteris cambrensis were effective against H. contortus adults. In concentration 0.1 mg/mL, A. distentifolium, D. aemula, D. cambrensis significantly decreased the viability of females from ISE and WR strains to 36.2%, 51.9%, 32.9% and to 35.3%, 27.0%, 23.3%, respectively in comparison to untreated controls. None of the extracts exhibited toxicity in precise cut slices from ovine liver. Polyphenol's analysis identified quercetin, kaempferol, luteolin, 3-hydroxybenzoic acid, caffeic acid, coumaric acid and protocatechuic acid as the major components of these anthelmintically active ferns. [ABSTRACT FROM AUTHOR]

Premise of research. Polyploidy and hybridization are prevalent and widespread phenomena in plants. The genetic consequences of genome duplication are numerous, but we understand very little about the comparative ecology of polyploids. In particular, the ways in which hybrid and polyploid offspring differ in ecology relative to their parents and relatives are poorly known. Among angiosperms, the triploid bridge is hypothesized to accrue some marginal fitness benefit to parent species from mostly sterile hybrid offspring. Because of the complexities of the fern life cycle, involving two free-living life stages, the ability to backcross via a triploid bridge should be more limited. If the triploid sporophyte offspring provide no fitness benefit to parents via subsequent generations, this raises the question about whether triploids further compete with parents by occupying similar ecological niches. We investigated comparative ecophysiology across light and wetness gradients of five members of the hybrid wood fern complex, Dryopteris. Methodology. We selected two related triads. Each triad consisted of a triploid and its diploid and tetraploid progenitor species: the D. × triploidea (3n) triad, with the parents D. carthusiana (4n) and D. intermedia (2n), and the D. × bootii (3n) triad, with the parents D. cristata (4n) and D. intermedia (2n). We sampled the temperature and relative humidity, population abundance and relative frequency, photosynthetic parameters, and hydraulic conductivity of populations to examine the extent of shared ecological niche space. Pivotal results. We found that triploids varied in habitat space relative to their parents. In the case of the triploid D. × bootii , this taxon occupied habitats similar to those of its parents at similar abundances and frequencies. In the case of D. × triploidea , the hybrid occurred across a more diverse range of habitats, which was more similar to its diploid parent. In both triads, the triploid's photosynthetic rate was intermediate between those of its parents, and the majority of the photosynthetic parameters were similar to those of the parents. There were some differences in hydraulic conductivity: xylem-specific hydraulic conductivity of the triploid D. × bootii was significantly higher than that of its diploid parent. Conclusions. Our results show that related triploids, diploids, and tetraploids substantially overlap in morphological and physiological niche space. The high relative frequency of triploids in habitats and the lack of clear niche partitioning within triads suggest that in addition to not contributing to parental reproductive fitness, the triploids could also negatively impact their progenitors by potentially competing for space and light resources in similar ways. [ABSTRACT FROM AUTHOR]

A number of studies were undertaken in the territory of the "Syrovatka river basin of the Emerald Network of Ukraine (UA0000428 Syrovatka river basin). Based on the data gathered from field work surveys of the area, the characteristics of the habitats (C1.222, C1.224, C1.32, C1.33, C2.33+, С2.34, C3.4, C3.51, D5.2, E1.2, E2.2, E3.4, E5.4, F3.247, F9.1+G1.11, G1.21+G1.41, G1.A1, G1.7, G1.8, G1.A4) are presented according to the area covered and their ecological features. Phytosociological characteristics of habitats were given. As a result of the analysis of the distribution of certain species of sozophytes, a brief description of the status of the identified populations was presented. Populations of vascular plant species protected in Europe (Ostericum palustre, Iris hungarica), Ukraine (Epipactis helleborine, Lilium martagon, Platanthera bifolia), and at the regional level (Carpinus betulus, Campanula persicifolia, Calla palustris, Dryopteris cristata, Inula helenium, Utricularia vulgaris) have been studied in detail. The main threats to the existence of the natural complex of this area, which may appear in the situation of increasing economic impact are drainage and ploughing of floodplains, terracing, and afforestation of meadow-steppe slopes of the ravine. The typological characteristics of artificial and natural forest plantations of the territory were described based on the generalization of details gathered from information on their local management. [ABSTRACT FROM AUTHOR]

Background: Hyperglycemia when sustained leads to diabetes which has become a chronic disorder having morbidity and mortality rate. This study investigated the effect of methanolic leaf extract of Dryoptersis dilatata (MEDd) on kidney injury caused on streptozotocin (STZ)-induced diabetic Wistar rats. Materials and Methods: Thirty Wistar rats were divided into five groups of six rats each. Group 1 received distilled water (10 ml/kg); Group 2 received STZ (60 mg/kg) only, Groups 3 and 4 received STZ followed by 400 and 800 mg/kg of MEDd, respectively, while Group 5 received STZ + Pioglitazone (10 mg/kg). After 2 weeks of treatment, rats were sacrificed and blood, spleen, liver, pancreas, and kidney were collected for biochemical analysis. Results: The results showed that MEDd extract caused a significant decrease (P < 0.05) in STZ-induced diabetic rats, oxidative stress markers, malondialdehyde nitric oxide, and glutathione superoxide were ameliorated in organs such as the kidney and pancreas in diabetic rats after treatment with MEDd. Kidney markers (urea and creatinine) were ameliorated as well as reduction in organ weights in diabetic rats following treatment with MEDd. Conclusion: Therefore, it was observed from our study that MEDd has antidiabetic and nephron-protective capacity as it ameliorates in vivo adopted in lieu of nephropancreatic caused by STZ-induced diabetes. [ABSTRACT FROM AUTHOR]

Traditional medicinal plants are a possible source of anti-malarial and anti-typhoid medications, and there is growing interest in the usage and development of herbal medicinal therapies for these ailments. The study aims to investigate the anti-malaria and anti-typhoid properties of Dryopteris dilataa leaves in silico. The plant leaves were extracted in ethanol and analyzed using Fourier transform infrared spectrometer (FTIR) and gas chromatography-mass spectrometry (GC--MS). The drug likeness and ADME predictions were done with OSIRIS property explorer and ADMETSAR webserver, while the molecular docking against dehydrogenase (Malaria target) and D-glutamate ligase enzyme (Typhoid Target) was done using Autodock Vina. The FT-IR results indicated the presence of -OH, CH3, C-H aromatic and C=O functional groups while the GC-MS revealed thirteen (13) potential medicinal compounds, nine (9) compounds showed good pharmacokinetic properties having high human intestinal absorption, less toxic and good overall drug score. The molecular docking study revealed that three compounds, 1,2,3,4,7,8,9,10-Octahydro-12H-[1]benzothieno[2,3-d]pyrido[1,2- a]pyrimidin-12-one (-6.7 Kcal/mol), 4,7,9-Trihydroxy-2-methylnaphtho[2,3-b]furan-5,8-dione (- 6.0 Kcal/mol), and 1,2,3-Triazol, 2-(E-4,4-dicyano-3-N-methylanilino-1,3-butadien-1-yl)-4- (methoxycarbonyl) (-6.3 Kcal/mol), gave better score for binding affinity than the control antimalarial drug artesunate (-5.9 Kcal/mol). The typhoid docking also revealed the compounds, 4,7,9-trihydroxy-2-methylnaphtho[2,3-b]furan-5,8-dione (-8.6 Kcal/mol) and 1,2,3-Triazol, 2- (E-4,4-dicyano-3-N-methylanilino-1,3-butadien-1-yl)-4-(methoxycarbonyl)- (-8.3 Kcal/mol) had better binding affinity score than the reference anti-typhoid drug Ciprofloxacin (-8.1 Kcal/mol). The research justifies the local claims on the use of the plant and strengthens the relevance of these compounds as promising lead candidates for the treatment of Malaria and typhoid. [ABSTRACT FROM AUTHOR]

Premise: Apomixis and hybridization are two essential and complementary factors in the evolution of plants, including ferns. Hybridization combines characteristics from different species, while apomixis conserves features within a lineage. When combined, these two processes result in apo‐sex hybrids. The conditions leading to the formation of these hybrids are poorly understood in ferns. Methods: We cultivated spores from 66 fern samples (43 apomicts, 7 apo‐sex hybrids, and 16 sexuals), and measured their development in vitro over 16 weeks. We evaluated germination, lateral meristem formation rates, sexual expression, and production of sporophytes and then compared ontogenetic patterns among the three groups. Results: The three examined groups formed antheridia (male gametangia) but differed in overall gametophyte development. Sexual species created archegonia (female, 86% of viable samples), but no sporophytes. Apomicts rarely created nonfunctional archegonia (8%) but usually produced apogamous sporophytes (75%). Surprisingly, apomictic and sexual species showed similar development speed. The sexually reproducing parents of viable studied hybrids formed about twice as many meristic gametophytes as the apomictic parents (39% vs. 20%, respectively). Conclusions: We present the most thorough comparison of gametangial development of sexual and apomictic ferns, to date. Despite expectations, apomictic reproduction might not lead to earlier sporophyte formation. Apomicts produce functional sperm and thus can contribute this type of gamete to their hybrids. The development patterns found in the parents of hybrids indicate a possible increase of hybridization rates by antheridiogens. The apo‐sex hybrids always inherit the apomictic reproductive strategy and are thus capable of self‐perpetuation. [ABSTRACT FROM AUTHOR]

Premise: Few studies have explored competition in fern gametophyte populations. One limiting factor is the tedious measurement of gametophyte size as a proxy for biomass in these small plants. Here, an alternative approach of estimating the number of green pixels from photos was employed to measure the competitive interactions among apomictic and sexual Dryopteris gametophytes. Methods: We cultivated the gametophytes of two apomictic (diploid and triploid) and one sexual (tetraploid) Dryopteris species in monocultures and in two‐species mixtures in the ratios 1 : 1 and 1 : 3. The total gametophyte cover of each population originating from 20 spores was assessed using Easy Leaf Area. Assessments were performed weekly between weeks 4 and 10 of cultivation. Additionally, during week 5, the cover of each species in each mixture was estimated separately. Results: We identified a positive correlation between gametophyte size and ploidy level as well as sexual reproduction. The performance of the tested species in mixtures was dependent on the competitor species identity, indicating the importance of competition between gametophytes. Discussion: The methods outlined can be used for a rapid assessment of fern gametophyte cover in large gametophyte populations. Ploidy level and reproduction type seem to play a major role in the competitive abilities of fern gametophytes, but more research is needed on this topic. [ABSTRACT FROM AUTHOR]

Abstract Premise Few studies have explored competition in fern gametophyte populations. One limiting factor is the tedious measurement of gametophyte size as a proxy for biomass in these small plants. Here, an alternative approach of estimating the number of green pixels from photos was employed to measure the competitive interactions among apomictic and sexual Dryopteris gametophytes. Methods We cultivated the gametophytes of two apomictic (diploid and triploid) and one sexual (tetraploid) Dryopteris species in monocultures and in two‐species mixtures in the ratios 1 : 1 and 1 : 3. The total gametophyte cover of each population originating from 20 spores was assessed using Easy Leaf Area. Assessments were performed weekly between weeks 4 and 10 of cultivation. Additionally, during week 5, the cover of each species in each mixture was estimated separately. Results We identified a positive correlation between gametophyte size and ploidy level as well as sexual reproduction. The performance of the tested species in mixtures was dependent on the competitor species identity, indicating the importance of competition between gametophytes. Discussion The methods outlined can be used for a rapid assessment of fern gametophyte cover in large gametophyte populations. Ploidy level and reproduction type seem to play a major role in the competitive abilities of fern gametophytes, but more research is needed on this topic.

Ethnopharmacological Relevance: The Dryopteris crassirhizoma Nakai., a commonly used herb, is known as "Guan Zhong" in China, "Oshida" in Japan and "Gwanjung" in Korea. It has long been used for parasitic infestation, hemorrhages and epidemic influenza., Aim of the Review: The present paper aims to provide an up-to-date review at the advancements of the investigations on the traditional use, phytochemistry, pharmacological activity, toxicology and pharmacokinetics of D. crassirhizoma. Besides, possible trends, therapeutic potentials, and perspectives for future research of this plant are also briefly discussed., Materials and Methods: Relevant information on traditional use, phytochemistry, pharmacological activity, toxicology and pharmacokinetics of D. crassirhizoma was collected through published materials and electronic databases, including the Chinese Pharmacopoeia, Flora of China, Web of Science, PubMed, Baidu Scholar, Google Scholar, and China National Knowledge Infrastructure. 109 papers included in the article and we determined that no major information was missing after many checks. All authors participated in the review process for this article and all research paper are from authoritative published materials and electronic databases., Results: 130 chemical components, among which phloroglucinols are the predominant groups, have been isolated and identified from D. crassirhizoma. D. crassirhizoma with its bioactive compounds is possessed of extensive biological activities, including anti-parasite, anti-microbial, anti-viral, anti-cancer, anti-inflammatory, anti-oxidant, anti-diabetic, bone protective, immunomodulatory, anti-platelet and anti-hyperuricemia activity. Besides, D. crassirhizoma has special toxicology and pharmacokinetics characterization., Conclusions: D. crassirhizoma is a traditional Chinese medicine having a long history of application. This review mainly summarized the different chemical components extract from D. crassirhizoma and various reported pharmacological effects. Besides, the toxicology and pharmacokinetics of D. crassirhizoma also be analysed in this review. However, the chemical components of D. crassirhizoma are understudied and require further research to expand its medicinal potential, and it is urgent to design a new extraction scheme, so that the active ingredients can be obtained at a lower cost., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Here we investigate the morphology of the spores of 12 native taxa of Dryopteridaceae that grow in Malakand division, Pakistan; most of these species not fully described before. This study intends to survey the taxonomic significance of spore morphological features and their variation useful for species identification in 7 species of Polystichum and 5 taxa of Dryopteris. The spores examinations were accomplished utilizing a light microscope (LM), and scanning electron microscope (SEM). The spores are monolete, medium‐sized, with variable shapes in both equatorial and polar views. The mean estimation of equatorial diameter ranging from 28.3 to 58.3 μm and the polar diameter varied from 27.6 to 45.8 μm. The exospore thickness ranges between 1.6 to 3.8 μm, and the thickness of perispore is 0.8–6.7 μm. The perispore is perforated, ornamentation elements occur in different ways in the studied taxa of Polystichum. In investigated Dryopteris taxa, rugate perispore type is found. Results of multivariate statistical analysis (UPGMA, and PCA) established on quantitative and qualitative morphological traits of spores demonstrate that the species form distinct groups, not reflecting any phylogenetic relationships. A key to the spores types is provided for species identification, which dependent on the diagnostic characters of spores. The results of this study indicate that variation of spore morphological traits; in particular, the ornamentation and perispore characteristics, which is surface texture, have diagnostic value at the species level. Our data will help in the identification of spores of the family Dryopteridaceae in palynological and taxonomic studies. [ABSTRACT FROM AUTHOR]

Athyrium filix-femina and Dryopteris affinis subsp. affinis are forest ferns that live together frequently. Spore viability and speed in germination, together with gametophyte development are cues for the competitive success of ferns in a certain habitat. Monospecific and mixed spore cultures were established, and kept at 10o, 15o and 20oC, and at low light intensity, from 1.8 to 1.0 µmol m-2 s-1, the latter at 20 oC. Total germination percentages and time (T50), were registered in each case. In addition, gametophyte development and sexual expression was studied in both species. Final germination percentages were generally high, slightly higher in cultures with mixed spores. However, temperature clearly affected germination time that was shorter in Dryopteris at all tested temperatures. Cultures at low light intensities reached high germination percentages, decreasing markedly at 1 µmol m-2 s-1, notably in Athyrium. Sexual expression in mixed cultures, on soil at 20°C and 50 µmol m-2 s-1, was similar after three and six months. Athyrium showed high percentages of female gametophytes promoting sporophytic outcrossing, while Dryopteris showed a high number of apogamous sporophytes. [ABSTRACT FROM AUTHOR]

Abstract The spore morphology and wall ultrastructure of Dryopteris filix-mas, D. patula and D. wallichiana from Argentina were studied using light microscope, scanning and transmission electron microscope. The study was carried out with herbarium material from Argentine institutions. Equatorial diameters, polar diameters and laesura length were measured. The spores are monoletes with a rugate ornamentation. The folds are short to long, inflate, irregular in shape and size, and varying from subglobose to elongate. The perispore surface is rugulate. The exospore of all the species analyzed is two-layered in section. Simple and branched channels are also present. The perispore is composed of two layers, the inner one forms the ornamentation and the outer covers all the outer and inner surfaces. Some abnormalities, such as globose, triangular or twisted spores were observed. The morphology and ultrastructure of the species are very similar. The differences observed are related to the length and thickness of the perispore folds. The characteristics of these spores would not provide relevant information to differentiate species or sections within the genus, but can provide information for phylogenetic studies as well as for alterations in the biological cycles.

Environmental context: Rare earth elements (REEs) are strategic metals and emerging contaminants for which plant-based remediation measures are needed. We screened a collection of hardy ferns and identified new accumulator species that preferentially transferred light REEs to their fronds. This study is an important step towards understanding the mechanisms of REE accumulation in plants. Rare earth elements (REEs) include the lanthanides plus yttrium and scandium, and can be split according to their atomic mass into light (LREEs) and heavy REEs (HREEs). The increasing demand for REEs is mainly driven by new technologies, and their current low recyclability has led them to become emerging contaminants. The identification of new REE accumulators may help in determining the REE transfer mechanisms and may result in interesting candidates for phytoremediation techniques. To that end, a collection of 49 hardy fern species, grown in REE-spiked substrate, were screened for their potential in REE accumulation. REE concentrations were very low in the fronds of all Polypodium species, whereas all Athyrium species highly accumulated REEs. The REE accumulation level was more variable among the different species of Dryopteris , Blechnum , Woodwardia , Cystopteris and Polystichum. However, whatever the species, LREEs were preferentially transferred to the fronds over HREEs. This conserved trait was independent of the availability of different REEs in the substrate and instead may arise from specific transfer systems in ferns for the two groups of REEs. Furthermore, REE accumulation was correlated to Ca and Al, which suggested the existence of common uptake pathways. Altogether, these results are of great interest for phytoremediation purposes since appropriate species can be chosen according to the area to be remediated, and they also provide new insights into a more in-depth characterisation of the underlying REE accumulation mechanisms in ferns. Environmental context. Rare earth elements (REEs) are strategic metals and emerging contaminants for which plant-based remediation measures are needed. We screened a collection of hardy ferns and identified new accumulator species that preferentially transferred light REEs to their fronds. This study is an important step towards understanding the mechanisms of REE accumulation in plants. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Arachniodes is a notoriously known for its taxonomic difficulty and chaos. • A large global sampling (275 accessions vs. 2–17 accessions in earlier studies) is achieved. • Arachniodes s.s. is monophyletic and resolved into 12 major clades. • The New World Arachniodes is not monophyletic. • Arachniodes might contain 83 species worldwide. Abstract Arachniodes (Dryopteridaceae) is one of the most confusing and controversial fern genera in terms of its circumscription, nomenclature, and taxonomy. Estimates of species number range from 40 to 200. Previous molecular works included only 2–17 accessions representing 2–12 species of Arachniodes and allied genera, leaving most of the Asian species remain unsampled and the infragneric relationships unclear. In this study DNA sequences of seven plastid markers of 343 accessions representing ca. 68 species of Arachniodes (275 accessions), and 64 outgroup accessions from subfam. Dryopteridoideae and subfam. Polybotryoideae were used to infer a phylogeny with maximum likelihood, Bayesian inference, and maximum parsimony approaches. Our major results include: (1) Two species currently assigned in Arachniodes (A. macrostegia and A. ochropteroides are resolved outside of the core Arachniodes making the currently defined Arachniodes polyphyletic, confirming earlier findings; (2) Lithostegia , Leptorumohra , and Phanerophlebiopsis are indeed synonyms of Arachniodes ; (3) Leptorumohra is confirmed to be monophyletic, but Phanerophlebiopsis is polyphyletic; (4) The New World species of Arachniodes are confirmed to be not monophyletic with A. denticulata being nested within the Old World species, suggesting that this species is dispersed from the Old World; (5) Arachniodes s.s is resolved into 12 major clades, some of which are further divisable into recognizable subclades and groups, with A. mutica from Japan being resolved as the sister to the rest of the genus; (6) A number of systematic implications of the phylogeny have been suggested; and (7) the genus is estimated to contain ca. 83 species. [ABSTRACT FROM AUTHOR]

Abstract Dryopteris fragrans (L.) Schott is a traditional herbal medicine containing medicinal sterols and triterpenoids. Squalene synthase (SQS) is the first crucial enzyme in the biosynthesis pathway of sterols and triterpenoids. The full-length cDNA named DfSQS1 was isolated by RACE. It was predicted that DfSQS1 contained an open reading frame (ORF) of 1239 bp coding 412 amino acid residues with molecular weight of 46.6 kDa. It had 18 potential phosphorylation sites, 1 potential N-glycosylation site and 2 transmembrane domains. In neighbor-joining (NJ) phylogenetic tree, DfSQS1 was away from branch of gymnosperms and angiosperms. One hydrophobic domain at the C-terminal of DfSQS1 was deleted to express soluble recombinant enzyme. The truncated DfSQS1 (tDfSQS1) was expressed in Escherichia coli BL21 (DE3). Then, tDfSQS1 was obtained and incubated with farnesyl diphosphate (FPP) to identify its enzymatic activity. The result demontrated that squalene, the product of enzyme catalyzed reaction, was detected by HPLC. Quantitative real-time PCR (qRT-PCR) analysis revealed that the transcription level of DfSQS1 in D. fragrans was the highest in roots, followed by leaves and rhizomes. This work is the first report on cloning, characteration and expression of SQS from D. fragrans. It will be helpful to understand the regulatory role of SQS on the biosynthesis of triterpenoids in the fern. Highlights • We cloned a squalene synthase (SQS) gene from a fern, Dryopteris fragrans, and named DfSQS1. • The nucleotide sequence and protein sequence were analyzed with bioinformatics softwares. • The gene had the strongest expression level in the roots, followed by leaves and rhizomes. • Different length of expression vectors were constructed, and it was transmitted into Escherichia coli BL21 (DE3) to express protein. • However, the full-length ORF could not be expressed successfully. • Only truncated DfSQS1 was expressed and purified. • We characterised its enzyme activity by HPLC. • This is the first report of cloning, characteration and expression of squalene synthase from D. fragrans and the first squalene synthase gene in fern. [ABSTRACT FROM AUTHOR]

Flavonoids are secondary metabolites of plants that often have medical applications. The influences of different sample drying pretreatments on flavonoids and antioxidant activity of ferns have not studies. Dryopteris erythrosora leaves used to analyze flavonoid alterations resulting from drying pretreatments. The total flavonoid content of D. erythrosora leaves exposed to different pretreatments was significantly different. The total flavonoid content of samples initially air-dried in shade and then oven-dried at 75°C were the highest (7.6%), while samples initially dried at 75°C had the lowest content (2.17%). Antioxidant activities of D. erythrosora leaves with different pretreatments varied. Group B first air-dried in the shade and then oven-dried at 75°C and group C first air-dried in the sun and then oven-dried at 75°C, both showed relatively stronger antioxidant activity. The best pretreatment for preserving the flavonoids was to first dry the plant material in the shade and then complete the drying process in an oven at 75°C. It was tentatively identified 22 flavonoids among the four different pretreatments by HPLC-ESI-TOF-MS. [ABSTRACT FROM AUTHOR]

Initiation and proliferation of leaf primordia, leaf expansion and maturation of a basket fern Dryopteris wallichiana are described based on two years of observation. The phenology of these events is strictly seasonal beginning with the onset of spring in the temperate Himalayan climate. Leaf primordia initiated during late summer often remain dormant but expand in the next growing season. Maturation of most of the leaves of a growing season is completed before the start of winter, but these withstand the winter cold. Leaves of the previous growing season remain erect on the rhizome for about 20 months after which they collapse. Significance of the presence of green and dry collapsed leaves on the rhizome is discussed. [ABSTRACT FROM AUTHOR]

The article discusses the potential invasiveness of Dryopteris erythrosora (Dryopteridaceae) in North America. Topics discussed include a plant identification course at the University of North Georgia that discovered a large colony of D. erythrosora spreading aggressively down a moist embankment in Alpharetta, Georgia and stem count from population in Alpharetta.

We analyzed the endogenous phytohormones composition and dynamics in the fronds and rhizomes of perennial fern Dryopteris filix-mas using high-performance liquid chromatography in combination with mass spectrometry. Samples were selected at the following phenological phases: an intensive growth (30.04), sori ripening (29.05), spores release (17.06), summer vegetation (10.07) and vegetation termination (21.10). It was shown that the content of indole-3-acetic acid (IAA) and abscisic (ABA) acids in fronds was higher that in rhizomes. Conjugated IAA accumulated in rhizome during spring vegetation at the phase of intensive growth. In contrast, the active form of ABA was dominant in fronds. During the development of sori, spores maturation and their falling, the quantity of free IAA and ABA in fronds increased. At the end of the vegetation the content of IAA and ABA reached its maximum with the predominance of conjugated IAA in fronds and rhizomes, and free ABA - in fronds. The maximum content of free gibberellic acid (GA3) was in fronds at the phase of active metabolism, whereas the higher level of conjugated form was in rhizomes in the autumn vegetation phase during the sporophyte transition to dormancy. The obtained results indicated that support of the auxin homeostasis during the transition from intensive growth to the formation and maturation of spores in sori and at the end of the vegetation involved conjugation mechanisms, and in the period of mass falling of mature spores - metabolic strategies of biosynthesis / catabolism. The dynamics and localization of GA3 showed that hormone was involved in the regulation of spores development and maturation. The character of the ABA accumulation indirectly confirmed the involvement of the hormone in the activation of protective adaptation processes in the autumn vegetation. [ABSTRACT FROM AUTHOR]

Dryopteris and Polystichum are the 2 complex taxonomic genera of Dryopteridaceae. The comparative foliar epidermal anatomy of 12 species of both genera from Pakistan were studied using standard protocols of light microscopy (LM) and scanning electron microscopy (SEM). The objective of which was systematic comparison and investigation to elucidate the taxonomic importance of foliar micromorphology, which may be useful to taxonomists for identifying complex Dryopteridaceae taxa. Principal component analysis and UPGMA clustering analysis were performed to test the validity of leaf anatomical features as method of separating species and genera. The foliar epidermal anatomy described here is a good source of taxonomic characters in both groups that can help genera and species delimitation. This is the first report on leaf micromorphology in most of these species. Observation of foliar anatomy showed that stomata are only present on the abaxial surface; i.e., leaves of all species are hypostomatic. The shapes of epidermal cells in all studied species are irregular. The anticlinal walls are strongly lobed, irregular wavy and elongated wavy. However, substantial variation in epidermal cell size and other stomatal features were observed on both upper and lower surfaces in all investigated species. Two types of stomata were observed in all studied species. The presence of polocytic stomata in Dryopteris and staurocytic stomata in Polystichum are the important characters for the segregation of these genera. Elongate elliptic stomatal shape, narrow kidney shaped guard cells and broad elliptic shaped stomatal pores are diagnostic for all five species of Dryopteris selected. On the other hand, size and number of epidermal cells, lobes per cell, stomatal size, subsidiary cell size, stomatal pore size and stomatal index are the key features for species differentiation in Polystichum . An identification key was developed in order to apply the foliar anatomical characters in the discrimination of the species studied. [ABSTRACT FROM AUTHOR]

Background: Dryopteris fragrans (D. fragrans) is a potential medicinal fern distributed in volcanic magmatic rock areas under tough environmental condition. Sporangia are important organs for fern reproduction. This study was designed to characterize the transcriptome characteristics of the wild D. fragrans sporangia in three stages (stage A, B, and C) with the aim of uncovering its molecular mechanism of growth and development. Results: Using a HiSeq 4000, 79.81 Gb clean data (each sample is at least 7.95 GB) were obtained from nine samples, with three being supplied from each period, and assembled into 94,705 Unigenes, among which 44,006 Unigenes were annotated against public protein databases (NR, Swiss-Prot, KEGG, COG, KOG, GO, eggNOG and Pfam). Furthermore, we observed 7126 differentially expressed genes (DEG) (Fold Change > 4, FDR < 0.001), 349,885 SNP loci, and 10,584 SSRs. DEGs involved in DNA replication and homologous recombination were strongly expressed in stage A, and several DEGs involved in cutin, suberin and wax biosynthesis had undergone dramatic changes during development, which was consistent with morphological observations. DEGs responsible for secondary metabolism and plant hormone signal transduction changed clearly in the last two stages. DEGs homologous to those known genes associated with the development of reproductive organs of flowering plants have also been validated and discussed, such as AGL61, AGL62, ONAC010. In particular, a Unigene encoding TFL1, an important flower–development regulator in flowering plants, was identified and exhibited the highest expression level in stage B in D. fragrans sporangia. Conclusions: This study is the first report on global transcriptome analysis in the development of sporangia of wild D. fragrans. DEGs related to development and homologous to flower-seed development in flowering plants were discussed. All DEGs involved in DNA replication and homologous recombination were consistent with morphological observations of paraffin slices. The results of this study provide rare resources for further investigation of the D. fragrans sporangium development, stress resistance and secondary metabolism. [ABSTRACT FROM AUTHOR]

The most abundant fern species in northeast United States forests are wintergreen. These ferns keep their fronds for one year before replacing them in the spring. The wintergreen fronds soften at their base in fall and survive the winter under snow, allowing vernal photosynthesis and providing an energetic benefit to the plant. This study addressed whether or not the softening of the stipe is critical to the evolutionary adaptiveness of the wintergreen leaf habit. I kept the fronds of 12 Dryopteris intermedia plants upright through the winter of 2015-2016 and left those of 12 other plants prostrate as controls. In the spring of 2016, a greater proportion of the frond surface area had frost damage on the upright fronds than on the control plants, and a greater proportion of the fronds were broken in the upright plants than in the control plants. The softening of the stipe was probably a critical step in the evolution of the wintergreen habit in D. intermedia. [ABSTRACT FROM AUTHOR]

On the basis of five phytosociological relevés, the fern-meadow vegetation with Oreopteris limbosperma and Dryopteris cambrensis from the region around Oban, Argyll, West Scotland is described and compared with similar communities in the Netherlands and West Germany. It is concluded that these fern-meadows can be assigned to the Luzulo luzuloides-Thelypteridetum limbospermae, which in Central and continental West Europe is restricted to forest edges. In West Scotland this community is also common in open landscapes, due to the hyperatlantic climate. In comparison with the fern communities in the Netherlands and Germany, the Scottish examples are very rich in fern species, illustrating the optimal development of the community in West Argyll. Possible future development of this community in the Netherlands are discussed in the light of the increase in records of Oreopteris limbosperma and the ecological requirements of Dryopteris cambrensis. [ABSTRACT FROM AUTHOR]

Dryopteris blanfordii (C.Hope) C.Chr. is a member of the Dryopteridaceae, growing in high altitude Picea or Abies forests (2900-3500 m) in China and India. Phylogenetic relationships between D. blanfordii subsp. nigrosquamosa and closely related species of Dryopteris were investigated using a combined analysis of multiple molecular data sets (the protein-coding region of rbcL and matK genes and intergenic spacers psbA-trnH, trnP-petG, rps4-trnS, trnL-trnF and rbcL-accD). An assumption about the position of D. blanfordii subsp. nigrosquamosa within Dryopteris was made by using the Maximum Likelihood and Bayesian Inference approach and chloroplast marker sequences of Dryopteris species from GenBank. The results demonstrated that Asian taxa D. blanfordii subsp. nigrosquamosa and D. laeta as well as two American species D. arguta and D. marginalis belong to the same clade, all four of them being part of Dryopteris section Dryopteris. [ABSTRACT FROM AUTHOR]

Premise of research. Ferns are vital components of temperate and tropical ecosystems, but they have not been examined in the context of a central-peripheral hypothesis. Dryopteris fragrans is an ideal species to examine the genetic variation between central and peripheral populations because of its arctic north to temperate south distribution pattern. In addition to understanding colonization dynamics, our study also addresses the issue regarding the conservation value of peripheral plant populations. Methodology. We examined 82 individuals from 22 populations from northern Canada (N-CA) and the northeastern United States (NE-US), which represent central and peripheral populations of D. fragrans, respectively. Two-hundred two loci were resolved using inter-simple sequence repeat markers, allowing analyses of genetic diversity and population structure, insights into gene flow and mating system, and correlations of genetic diversity with geographical distance, population size, and air temperature. Pivotal results. Dryopteris fragrans exhibits high genetic diversity at the species level, with most of its genetic variation due to differences between populations. At the regional level, however, there is a sharp contrast in the patterns of genetic variation between N-CA and NE-US populations, with the latter exhibiting low genetic diversity, high population differentiation, low gene flow, and a predominantly inbreeding mating system. The NE-US populations also exhibit several unique loci that indicate that they are not merely a reduced representative of the overall genetic diversity of the species. Conclusions. Dryopteris fragrans in the NE-US are genetically distinct from those in N-CA, and this result may serve as justification for the species' conservation in the NE-US. Our results also indicate that D. fragrans in the NE-US may have originated from the Canadian populations through several instances of single-spore founding events facilitated by long-distance spore dispersal and self-fertilization. [ABSTRACT FROM AUTHOR]

Background: Dryopteris erythrosora (D.C. Eaton) Kuntze is a species of fern in the family of Dryopteridaceae, which is distributed throughout East Asia. The genus Dryopteris has been used as traditional medicine, especially to treat hepatitis and protect liver. However, only few studies of chemical constituents of D. erythrosora have been conducted so far. Objective: In this study, we investigated the phytochemical constituents of D. erythrosora. Materials and Methods: The 80% methanol extract of the aerial part of D. erythrosora was used for the isolation of phenolic compounds. The isolated compounds were elucidated by various spectroscopic methods including nuclear magnetic resonance and mass spectrometry. Results: The present phytochemical investigation on the aerial part of D. erythrosora led to the isolation of two new phenolic glycosides, 1 and 2, as well as nine known flavonoids including two flavones (3 and 4) and seven flavonols (5-11). Conclusion: In this study, two new phenolic glycosides together with nine known flavonoids were isolated from the aerial part of D. erythrosora. Among them, compounds 4, 8, and 11 were isolated for the first time in Dryopteridaceae family from the present investigation. These results helped us to enrich our understanding of the chemical constituents of D. erythrosora and to identify compounds 1 and 2 which could be potential chemotaxonomic markers for the species. [ABSTRACT FROM AUTHOR]