ResearchPad - molecular-systematics https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[The complete mitochondrial genome sequence of <i/> L. Koch, 1878 (, ), with a comparative analysis of other centipede genomes]]> https://www.researchpad.co/article/elastic_article_12587 L. Koch, 1878 is an important Chinese animal with thousands of years of medicinal history. However, the genomic information of this species is limited, which hinders its further application. Here, the complete mitochondrial genome (mitogenome) of was sequenced and assembled by next-generation sequencing. The genome is 15,011 bp in length, consisting of 13 protein-coding genes (PCGs), 14 tRNA genes, and two rRNA genes. Most PCGs start with the ATN initiation codon, and all PCGs have the conventional stop codons TAA and TAG. The mitogenome revealed nine simple sequence repeats (SSRs), and an obviously lower GC content compared with other seven centipede mitogenomes previously sequenced. After analysis of homologous regions between the eight centipede mitogenomes, the mitogenome further showed clear genomic rearrangements. The phylogenetic analysis of eight centipedes using 13 conserved PCG genes was finally performed. The phylogenetic reconstructions showed as a separate group, and in a sister-group relationship with and . Collectively, the mitogenome provided new genomic resources, which will improve its medicinal research and applications in the future.

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<![CDATA[Discovery of a new species of the Hypoxylon rubiginosum complex from Iran and antagonistic activities of Hypoxylon spp. against the Ash Dieback pathogen, Hymenoscyphus fraxineus, in dual culture]]> https://www.researchpad.co/article/N42b420df-f01d-4492-b8d8-193894490051

Abstract

During a survey of xylarialean fungi in Northern Iran, several specimens that showed affinities to the Hypoxylon rubiginosum complex were collected and cultured. A comparison of their morphological characters, combined with a chemotaxonomic study based on high performance liquid chromatography, coupled with diode array detection and mass spectrometry (HPLC-DAD/MS) and a multi-locus phylogeny based on ITS, LSU, rbp2 and tub2 DNA sequences, revealed a new species here described as Hypoxylon guilanense. In addition, Hypoxylon rubiginosumsensu stricto was also encountered. Concurrently, an endophytic isolate of the latter species showed strong antagonistic activities against the Ash Dieback pathogen, Hymenoscyphus fraxineus, in a dual culture assay in our laboratory. Therefore, we decided to test the new Iranian fungi for antagonistic activities against the pathogen, along with several cultures of other Hypoxylon species that are related to H. rubiginosum. Our results suggest that the antagonistic effects of Hypoxylon spp. against Hym. fraxineus are widespread and that they are due to the production of antifungal phomopsidin derivatives in the presence of the pathogen.

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<![CDATA[Revision of the genus Hoplodrina Boursin, 1937 (Lepidoptera, Noctuidae, Xyleninae). I. Hoplodrina octogenaria (Goeze, 1781) and its sister species H. alsinides (Costantini, 1922) sp. rev. in Europe]]> https://www.researchpad.co/article/N0edc772b-3fac-452d-87a9-685bb59cfb30

Abstract

The taxonomic status of the European Hoplodrina octogenaria (Goeze, 1781) is discussed and its partly sympatric sister species, Hoplodrina alsinides (Costantini, 1922) sp. rev., is separated and re-described based on morphological and molecular taxonomic evidence. The adults and their genitalia are illustrated and DNA barcodes, as well as genome-wide single nucleotide polymorphism data collected by fractional genome sequencing (ddRAD), of the two species are provided.

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<![CDATA[The InBIO Barcoding Initiative Database: DNA barcodes of Portuguese Diptera 01]]> https://www.researchpad.co/article/N3175e8cf-63a3-4462-af46-c6b7c10dda20
Abstract

Background

The InBIO Barcoding Initiative (IBI) Diptera 01 dataset contains records of 203 specimens of Diptera. All specimens have been morphologically identified to species level, and belong to 154 species in total. The species represented in this dataset correspond to about 10% of continental Portugal dipteran species diversity. All specimens were collected north of the Tagus river in Portugal. Sampling took place from 2014 to 2018, and specimens are deposited in the IBI collection at CIBIO, Research Center in Biodiversity and Genetic Resources.

New information

This dataset contributes to the knowledge on the DNA barcodes and distribution of 154 species of Diptera from Portugal and is the first of the planned IBI database public releases, which will make available genetic and distribution data for a series of taxa. All specimens have their DNA barcodes made publicly available in the Barcode of Life Data System (BOLD) online database and the distribution dataset can be freely accessed through the Global Biodiversity Information Facility (GBIF).

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<![CDATA[Molecular phylogenetic study of the tribe Tropidieae (Orchidaceae, Epidendroideae) with taxonomic and evolutionary implications]]> https://www.researchpad.co/article/N67d0c8ad-70d0-42c3-8803-6849f5f30715
Abstract

The orchid tribe Tropidieae comprises three genera, Tropidia, Corymborkis and Kalimantanorchis. There are three fully mycoheterotrophic species within Tropidieae: Tropidia saprophytica, T. connata and Kalimantanorchis nagamasui. A previous phylogenetic study of K. nagamasui, based only on plastid matK data, placed K. nagamasui outside the clade of Tropidia and Corymborkis without support. In this study, we performed phylogenetic analyses using a nuclear ribosomal DNA spacer (ITS1-5.8S-ITS2), a low-copy nuclear coding gene (Xdh) and a mitochondrial intron (nad1b-c intron) to study the phylogenetic relationships within Tropidieae. We included six photosynthetic and all three fully mycoheterotrophic Tropidieae species. The resulting phylogenetic trees placed these fully mycoheterotrophic species inside the Tropidia clade with high support. In our trees, these three species do not form a monophyletic group together, because the photosynthetic T. graminea is nested amongst them. Our results also suggest that the loss of photosynthetic ability occurred at least twice in Tropidia.

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<![CDATA[Integrative taxonomy confirms three species of Coniocarpon (Arthoniaceae) in Norway]]> https://www.researchpad.co/article/N74f06736-99fa-4e3f-a241-02ddba5eaa51
Abstract

We have studied the highly oceanic genus Coniocarpon in Norway. Our aim has been to delimit species of Coniocarpon in Norway based on an integrative taxonomic approach. The material studied comprises 120 specimens of Coniocarpon, obtained through recent collecting efforts (2017 and 2018) or received from major fungaria in Denmark, Finland, Norway and Sweden, as well as from private collectors. We have assessed (1) species delimitations and relationships based on Bayesian and maximum likelihood phylogenetic analyses of three genetic markers (mtSSU, nucITS and RPB2), (2) morphology and anatomy using standard light microscopy, and (3) secondary lichen chemistry using high-performance thin-layer chromatography. The results show three genetically distinct lineages of Coniocarpon, representing C. cinnabarinum, C. fallax and C. cuspidans comb. nov. The latter was originally described as Arthonia cinnabarina f. cuspidans and is herein raised to species level. All three species are supported by morphological, anatomical and chemical data.

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<![CDATA[A new Diplolepis Geoffroy (Hymenoptera, Cynipidae, Diplolepidini) species from China: a rare example of a rose gall-inducer of economic significance]]> https://www.researchpad.co/article/Ne5007647-fb13-4787-93ae-25ed2fc5cf40
Abstract

A new species of the genus Diplolepis Geoffroy, Diplolepis abei Pujade-Villar & Wang sp. nov. is described on host plant Rosa sertata Rolfe × R. rugosa Thunb. from China with an integrative approach based on molecular and morphological data. Diagnosis, distribution and biology of the new species are included and illustrated. This species is the first known rose gall-inducer of economic importance. A review of Eastern Palearctic species of Diplolepis is given and a key to the Chinese fauna is presented.

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<![CDATA[Silene sunhangii (Caryophyllaceae), a new species from China]]> https://www.researchpad.co/article/Ne9ea15e5-dc9a-4c4e-9f01-bbecf6a930ca
Abstract

Silene sunhangii, a new species of Caryophyllaceae known from only three populations in Hubei and Hunan provinces of central China, is described. Both morphological and molecular data were used to assess the taxonomic status and relationships of this species. Morphologically, S. sunhangii is most similar to S. platyphylla Franch. from which it differs most readily in having 3-veined elliptical leaves without pubescence, tasseled catacorolla, pale purple to red petals without a linear lobe or narrow tooth and lanceolate, bifid to one third. A phylogenetic analysis based on nuclear ITS region identified the new species as a well-supported, independent lineage. Our new species is nested within a grade that encompasses species representing a polyphyletic Silene sect. Physolychnis (Benth.) Bocquet. Both the genetic and morphological data support the recognition of Silene sunhangii as a distinct species, although there is inconsistency between these two datasets as to the relationships of the new species.

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<![CDATA[Taxonomic studies on the Chara section Hartmania in Poland based on morphological and molecular data]]> https://www.researchpad.co/article/Nd848817e-f45b-4881-a3af-72e7ba7bdeeb
Abstract

Charophytes are aquatic green macroalgae, which inhabit fresh and brackish water ecosystems. In this study, four species belonging to the genus Chara were examined to determine their taxonomic status. Morphological characteristics of the plant bodies as well as plastid psaB barcoding genes were applied to test the relations among Chara species. Plants were initially classified using morphological features into four species: C. baltica, C. hispida, C. polyacantha and C. rudis, and twelve quantitative characters were used in a principal component analysis and discriminant analysis to determine groupings among the species and to determine the morphological features that best separated the groups. In the component analysis and discriminant analysis, results showed that only C. polyacantha and partly C. baltica formed separate groups. The other species C. hispida and C. rudis were only partially distinguishable. All species from one molecular group, and no differentiation in the psaB variability between them has been found.

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<![CDATA[The genus Massalongia (lichenised ascomycetae) in the Southern Hemisphere]]> https://www.researchpad.co/article/N80b64ecc-fbce-4acf-8d36-d42ab4f56aec
Abstract

The species of Massalongia recorded and described from the Southern Hemisphere are revised and it is shown that only one is present; M. patagonica which is widespread, with populations in Australia and New Zealand that differ from the South American populations, but at present best regarded as part of the variation of that species. Records from this hemisphere of all other species placed in the genus are incorrect. The type species, M. carnosa, is restricted to the Northern Hemisphere. Two species, M. antarctica and M. novozelandica cannot be identified precisely due to lack of sufficient type material and with the types as the only collections known of these, but none belongs in Massalongia according to available data. Massalongia griseolobata (from Gough Isl.) is shown here to belong in the Pannariaceae and is part of the parmelielloid clade. M. intricata (from South Georgia) and M. olechiana (from South Shetland) have both recently been correctly transferred to the genus Steinera in the Arctomiaceae.

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<![CDATA[Intraspecific variation and phylogeography of the millipede model organism, the Black Pill Millipede Glomerismarginata (Villers, 1789) (Diplopoda, Glomerida, Glomeridae)]]> https://www.researchpad.co/article/5c96bf32d5eed0c4848b5f2a
Abstract

The Black Pill Millipede, Glomerismarginata, is the best studied millipede species and a model organism for Diplopoda. Glomerismarginata is widespread, with numerous colour morphs occurring across its range, especially in the south. This study investigates whether colour morphs might represent cryptic species as well as the haplotype diversity and biogeography of G.marginata. The results of the COI barcoding fragment analysis include 97 G.marginata, as well as 21 specimens from seven potentially related species: G.intermedia Latzel, 1884, G.klugii Brandt, 1833 (G.undulata C.L. Koch, 1844), G.connexa Koch, 1847, G.hexasticha Brandt, 1833, G.maerens Attems, 1927, G.annulata Brandt, 1833 and G.apuana Verhoeff, 1911. The majority of the barcoding data was obtained through the German Barcode of Life project (GBOL). Interspecifically, G.marginata is separated from its congeners by a minimum uncorrected genetic distance of 12.9 %, confirming its monophyly. Uncorrected intraspecific distances of G.marginata are comparable to those of other widespread Glomeris species, varying between 0–4.7%, with the largest genetic distances (>2.5 %) found at the Mediterranean coast. 97 sampled specimens of G.marginata yielded 47 different haplotypes, with identical haplotypes occurring at large distances from one another, and different haplotypes being present in populations occurring in close proximity. The highest number of haplotypes was found in the best-sampled area, western Germany. The English haplotype is identical to northern Spain; specimens from southern Spain are closer to French Mediterranean specimens. Analyses (CHAO1) show that approximately 400 different haplotypes can be expected in G.marginata. To cover all haplotypes, it is projected that up to 6,000 specimens would need to be sequenced, highlighting the impossibility of covering the whole genetic diversity in barcoding attempts of immobile soil arthropod species.

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<![CDATA[Genome-enhanced detection and identification of fungal pathogens responsible for pine and poplar rust diseases]]> https://www.researchpad.co/article/5c648cebd5eed0c484c81ab7

Biosurveillance is a proactive approach that may help to limit the spread of invasive fungal pathogens of trees, such as rust fungi which have caused some of the world’s most damaging diseases of pines and poplars. Most of these fungi have a complex life cycle, with up to five spore stages, which is completed on two different hosts. They have a biotrophic lifestyle and may be propagated by asymptomatic plant material, complicating their detection and identification. A bioinformatics approach, based on whole genome comparison, was used to identify genome regions that are unique to the white pine blister rust fungus, Cronartium ribicola, the poplar leaf rust fungi Melampsora medusae and Melampsora larici-populina or to members of either the Cronartium and Melampsora genera. Species- and genus-specific real-time PCR assays, targeting these unique regions, were designed with the aim of detecting each of these five taxonomic groups. In total, twelve assays were developed and tested over a wide range of samples, including different spore types, different infected plant parts on the pycnio-aecial or uredinio-telial host, and captured insect vectors. One hundred percent detection accuracy was achieved for the three targeted species and two genera with either a single assay or a combination of two assays. This proof of concept experiment on pine and poplar leaf rust fungi demonstrates that the genome-enhanced detection and identification approach can be translated into effective real-time PCR assays to monitor tree fungal pathogens.

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<![CDATA[Development and validation of probe-based multiplex real-time PCR assays for the rapid and accurate detection of freshwater fish species]]> https://www.researchpad.co/article/5c5b52d9d5eed0c4842bd127

Reliable species identification methods are important for industrial environmental monitoring programs. Probe based real-time quantitative polymerase chain reaction (qPCR) provides an accurate, cost-effective and high-throughput method for species identification. Here we present the development and validation of species-specific primers and probes for the cytochrome c oxidase (COI) gene for the identification of eight ecologically and economically important freshwater fish species: lake whitefish (Coregonus clupeaformis), yellow perch (Perca flavescens), rainbow smelt (Osmerus mordax), brook trout (Salvelinus fontinalis), smallmouth bass (Micropterus dolomieu), round whitefish (Prosopium cylindraceum), spottail shiner (Notropis hudsonius) and deepwater sculpin (Myoxocephalus thompsonii). In order to identify novel primer-probe sets with maximum species-specificity, two separate primer-probe design criteria were employed. Highest ranked primer-probe sets from both methods were assayed to identify sequences that demonstrated highest specificity. Specificity was determined using control species from same genus and non-target species from different genus. Selected primer-probe sets were optimized for annealing temperature and primer-probe concentrations to identify minimum reagent parameters. The selected primer-probe sets were highly sensitive, with DNA concentrations as low as 1 ng adequate for positive species identification. A decoder algorithm was developed based on the cumulative qPCR results that allowed for full automation of species identification. Blinded experiments revealed that the combination of the species-specific primer/probes sets with the automated species decoder resulted in target species identification with 100% accuracy. We also conducted a cost/time comparison analysis between the qPCR assays established in this study with other species identification methods. The qPCR technique was the most cost-effective and least time consuming method of species identification. In summary, probe-based multiplex qPCR assays provide a rapid and accurate method for freshwater fish species identification, and the methodology established in this study can be utilized for various other species identification initiatives.

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<![CDATA[EMBL2checklists: A Python package to facilitate the user-friendly submission of plant and fungal DNA barcoding sequences to ENA]]> https://www.researchpad.co/article/5c40f7a5d5eed0c48438651a

Background

The submission of DNA sequences to public sequence databases is an essential, but insufficiently automated step in the process of generating and disseminating novel DNA sequence data. Despite the centrality of database submissions to biological research, the range of available software tools that facilitate the preparation of sequence data for database submissions is low, especially for sequences generated via plant and fungal DNA barcoding. Current submission procedures can be complex and prohibitively time expensive for any but a small number of input sequences. A user-friendly software tool is needed that streamlines the file preparation for database submissions of DNA sequences that are commonly generated in plant and fungal DNA barcoding.

Methods

A Python package was developed that converts DNA sequences from the common EMBL and GenBank flat file formats to submission-ready, tab-delimited spreadsheets (so-called ‘checklists’) for a subsequent upload to the annotated sequence section of the European Nucleotide Archive (ENA). The software tool, titled ‘EMBL2checklists’, automatically converts DNA sequences, their annotation features, and associated metadata into the idiosyncratic format of marker-specific ENA checklists and, thus, generates files that can be uploaded via the interactive Webin submission system of ENA.

Results

EMBL2checklists provides a simple, platform-independent tool that automates the conversion of common DNA barcoding sequences into easily editable spreadsheets that require no further processing but their upload to ENA via the interactive Webin submission system. The software is equipped with an intuitive graphical as well as an efficient command-line interface for its operation. The utility of the software is illustrated by its application in four recent investigations, including plant phylogenetic and fungal metagenomic studies.

Discussion

EMBL2checklists bridges the gap between common software suites for DNA sequence assembly and annotation and the interactive data submission process of ENA. It represents an easy-to-use solution for plant and fungal biologists without bioinformatics expertise to generate submission-ready checklists from common DNA sequence data. It allows the post-processing of checklists as well as work-sharing during the submission process and solves a critical bottleneck in the effort to increase participation in public data sharing.

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<![CDATA[DNA barcoding data release for Coleoptera from the Gunung Halimun canopy fogging workpackage of the Indonesian Biodiversity Information System (IndoBioSys) project]]> https://www.researchpad.co/article/5c5afb71d5eed0c48426001d
Abstract

We present the results of a DNA barcoding pipeline that was established as part of the German-Indonesian IndobioSys project - Indonesian Biodiversity Information System. Our data release provides the first large-scale diversity assessment of Indonesian coleoptera obtained by canopy fogging. The project combined extensive fieldwork with databasing, DNA barcode based species delineation and the release of results in collaboration with Indonesian counterparts, aimed at supporting further analyses of the data. Canopy fogging on 28 trees was undertaken at two different sites, Cikaniki and Gunung Botol, in the south-eastern area of the Gunung Halimun-Salak National Park in West Java, Indonesia. In total, 7,447 specimens of Coleoptera were processed, of which 3,836 specimens produced DNA barcode sequences that were longer than 300 bp. A total of 3,750 specimens were assigned a Barcode Index Number (BIN), including 2,013 specimens from Cikaniki and 1,737 specimens from Gunung Botol. The 747 BINs, that were obtained, represented 39 families of Coleoptera. The distribution of specimens with BINs per tree was quite heterogeneous in both sites even in terms of the abundance of specimens or diversity of BINs. The specimen distribution per taxon was heterogeneous as well. Some 416 specimens could not be identified to family level, corresponding to 72 BINs that lack a family level identification. The data have shown a large heterogeneity in terms of abundance and distribution of BINs between sites, trees and families of Coleoptera. From the total of 747 BINs that were recovered, 421 (56%) are exclusive from a single tree. Although the two study sites were in close proximity and separated by a distance of only about five kilometres, the number of shared BINs between sites is low, with 81 of the 747 BINs. With this data release, we expect to shed some light on the largely hidden diversity in the canopy of tropical forests in Indonesia and elsewhere.

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<![CDATA[Evidence of cryptic species in the blenniid Cirripectesalboapicalis species complex, with zoogeographic implications for the South Pacific]]> https://www.researchpad.co/article/5c394877d5eed0c484a412c5
Abstract

Rapa Nui, commonly known as Easter Island (Chile), is one of the most isolated tropical islands of the Pacific Ocean. The island location of Rapa Nui makes it the easternmost point of the geographic ranges for many western Pacific fish species that are restricted to the subtropical islands south of 20°S latitude. The blenniid fish species Cirripectesalboapicalis has been thought to have one of the most extensive geographic distribution ranges among these southern subtropical fish species, extending from the southern Great Barrier Reef to Rapa Nui. A phylogenetic analysis was conducted to determine the taxonomic status of the species. The results provide genetic evidence that suggests that this formerly South Pacific-wide species comprises at least three cryptic species with allopatric geographic distributions. The analyses reveal the geographic distributions of these clades and their genetic relationships with each other, and with other species within the genus Cirripectes. The processes that culminated in the current geographic distribution of this species complex and the zoogeographic implications of this finding for the South Pacific region are discussed.

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<![CDATA[Radiation of members of the Soroserishookeriana complex (Asteraceae) on the Qinghai-Tibetan Plateau and their proposed taxonomic treatment]]> https://www.researchpad.co/article/5c394873d5eed0c484a41179
Abstract

The existence of intermediate types is a major obstacle that can hinder the circumscription of species. Elucidating the mechanism responsible for intermediate types is essential for achieving a reasonable taxonomical treatment. In this study, we explored the evolutionary history and taxonomic treatment of the Soroserishookeriana (C.B.Clarke) Stebbins complex, which comprises six named taxa that may be taxonomically distinct and are all native to the Qingha-Tibetan Plateau (QTP). We made an investigation across the distribution range of Soroseris Stebbins and sampled 27 populations, mostly from the complex. Internal transcribed spacer (ITS) and two chloroplast loci were sequenced and analysed using the neighbour-joining and Bayesian inference methods. The resulting phylogenies show no well supported inconsistence in topologies, in line with the lack of incongruence detected by the length difference test. However, all the trees were largely unresolved within S.hookeriana complex, irrespective of the optimality criterion employed. We interpret these results as an experience of radiation, which is a common process for native genera on the QTP. Thus, we suggest that all of the morphotypes might be different forms, generated by incipient speciation due to recent explosive differentiation, possibly triggered by the drastic environmental changes of the QTP. Given their evolutionary history, we propose a pragmatic method for treating all of these species as subspecies with a total of four new combinations.

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<![CDATA[Taxonomic circumscription of melanconis-like fungi causing canker disease in China]]> https://www.researchpad.co/article/5c22c79bd5eed0c484aa6770
Abstract

Melanconis-like species comprise latent fungal pathogens with a wide range of woody hosts. Taxonomy of these pathogens is difficult due to their uninformative descriptions and similar asexual morphology. Based on molecular phylogenies, many species of this group were placed in various families of Diaporthales. In this study, eight species of melanconis-like fungi were isolated from Betulaalbosinensis, B.platyphylla (Betulaceae), Cornuscontroversa (Cornaceae), Corylusmandshurica (Betulaceae) and Juglansregia (Juglandaceae) in China. These species were phylogenetically placed in three families of Diaporhthales, i.e. Juglanconisjuglandina, J.oblonga (Juglanconidaceae), Melanconiellabetulicolasp. nov., M.corylinasp. nov. (Melanconiellaceae), Melanconisbetulae, Ms.itoana, Ms.stilbostoma (Melanconidaceae) and one new genus, Sheathospora (Melanconiellaceae). Sheathospora is proposed to accommodate Melanconiellacornuta with conical and discrete pycnidia with aseptate, hyaline, cylindrical to ellipsoidal conidia with distinct hyaline sheath on branches of Cornuscontroversa. Combined analyses of ITS, LSU, CAL, RPB2 and TEF1-α sequence data were used to construct the molecular phylogeny. Additionally, we provided separate phylogenetic trees for three families (Juglanconidaceae, Melanconidaceae and Melanconiellaceae) to show the species distribution of melanconis-like fungi in China.

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<![CDATA[Deepbinner: Demultiplexing barcoded Oxford Nanopore reads with deep convolutional neural networks]]> https://www.researchpad.co/article/5bfdb372d5eed0c4845c990b

Multiplexing, the simultaneous sequencing of multiple barcoded DNA samples on a single flow cell, has made Oxford Nanopore sequencing cost-effective for small genomes. However, it depends on the ability to sort the resulting sequencing reads by barcode, and current demultiplexing tools fail to classify many reads. Here we present Deepbinner, a tool for Oxford Nanopore demultiplexing that uses a deep neural network to classify reads based on the raw electrical read signal. This ‘signal-space’ approach allows for greater accuracy than existing ‘base-space’ tools (Albacore and Porechop) for which signals must first be converted to DNA base calls, itself a complex problem that can introduce noise into the barcode sequence. To assess Deepbinner and existing tools, we performed multiplex sequencing on 12 amplicons chosen for their distinguishability. This allowed us to establish a ground truth classification for each read based on internal sequence alone. Deepbinner had the lowest rate of unclassified reads (7.8%) and the highest demultiplexing precision (98.5% of classified reads were correctly assigned). It can be used alone (to maximise the number of classified reads) or in conjunction with other demultiplexers (to maximise precision and minimise false positive classifications). We also found cross-sample chimeric reads (0.3%) and evidence of barcode switching (0.3%) in our dataset, which likely arise during library preparation and may be detrimental for quantitative studies that use multiplexing. Deepbinner is open source (GPLv3) and available at https://github.com/rrwick/Deepbinner.

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<![CDATA[Quillworts from the Amazon: A multidisciplinary populational study on Isoetes serracarajensis and Isoetes cangae]]> https://www.researchpad.co/article/5b87837240307c3c45097671

Isoetes are ancient quillworts members of the only genus of the order Isoetales. The genus is slow evolving but is resilient, and widespread worldwide. Two recently described species occur in the Eastern Brazilian Amazon, Isoetes serracarajensis and Isoetes cangae. They are found in the ironstone grasslands known as Canga. While I. serracarajensis is present mostly in seasonal water bodies, I. cangae is known to occur in a single permanent lake at the South mountain range. In this work, we undertake an extensive morphological, physiological and genetic characterization of both species to establish species boundaries and better understand the morphological and genetic features of these two species. Our results indicate that the morphological differentiation of the species is subtle and requires a quantitative assessment of morphological elements of the megaspore for diagnosis. We did not detect differences in microspore output, but morphological peculiarities may establish a reproductive barrier. Additionally, genetic analysis using DNA barcodes and whole chloroplast genomes indicate that although the plants are genetically very similar both approaches provide diagnostic characters. There was no indication of population structuring I. serracarajensis. These results set the basis for a deeper understanding of the evolution of the Isoetes genus.

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