ITS Phylogeny Research Articles

A new species of Hypericum section Olympia (Hypericaceae) from Central Greece

Hypericum intricatum, discovered in an ophiolitic area near the city of Domokos, Central Greece, is here described and illustrated as a species new to science. It belongs to section Olympia, as indicated by nuclear ribosomal ITS phylogeny, congruent with several but not all key morphological characters of this taxon. The sole known population of the new species is critically small and restricted to a floristically noteworthy spot accompanied by other rare and threatened serpentine-specialist species.

Two new records of freshwater Sordariomycetes, Sporoschisma chiangraiense (Chaetosphaeriales) and Trichoderma pinicola (Hypocreales), from the Philippines

ABSTRACT One of our studies on lignicolous aquatic fungi in the Philippines yielded two new records of freshwater Sordariomycetes in the genera Sporoschisma and Trichoderma. The newly collected specimens, UPVMI 24–0003 and UPVMI 24–0004, exhibit morphological similarities to the holotypes of Trichoderma pinicola (SFC 20130926-S233) and Sporoschisma chiangraiense (MFLU 18–1722), respectively. Combined ITS-TEF1-α phylogenetic analysis showed that UPVMI 24–0003 clustered with the ex-type strain of T. pinicola (KACC 48486), and with T. simplex (HMAS 248842) as a sister taxon. The isolate UPVMI 24–0004 grouped with three strains of S. chiangraiense (MFLUCC 18-0703, MFLUCC 18-0336, and GMB0090), with 97% ML and 1.00 BYPP bootstrap supports in the ITS phylogeny. We provide detailed descriptions and illustrations for both T. pinicola and S. chiangraiense, along with a synopsis of morphological characters for freshwater Sporoschisma species.

Description of Nothotylenchus savadkoohensis n. sp. (Rhabditida, Anguinidae) from Iran based on morphological and molecular data.

Nothotylenchus savadkoohensis n. sp. was recovered from rotten wood samples of an unidentified forest tree in the Mazandaran province and described herein. It is mainly characterized by an elongated conoid tail ending in a sharply pointed tip and four lines in the lateral field. Females of the new species have 379-662 μm long bodies with 5.8-6.9 μm long stylets ending in fine posteriorly sloping knobs, the metacorpus not valvate, the pharyngeal bulb slightly overlapping the intestine, and the vulva at 76.5-84.0% of body length. Males are also common and have 13.0-14.5 μm long spicules and bursa cloacal. By having an elongated conoid tail and four lines in the lateral field, the new species comes close to four known species, namely N. acris, N. acutus, N. antricolus, and N. truncatus. The morphological differences between the new species and the abovementioned species are discussed. The new species was sequenced for its D2-D3 segment of LSU and ITS rDNA regions. In the LSU phylogenetic tree, the currently available LSU sequences of the genus Nothotylenchus occupied distant placements from each other and the LSU sequence of the new species formed clade with a sequence assigned to Neotylenchus sp. In ITS phylogeny, the newly generated sequence of the new species formed a clade with a clade that includes sequences of Ditylenchus sp. and Neomisticius platypi and N. variabilis.

Circinaria tominii (Megasporaceae, lichenized Ascomycota) is represented by two different growth forms

Molecular study of Circinaria specimens collected in arid habitats of the Chuya Steppe showed the existence of two different growth forms, crustose and vagrant, in C. tominii that implies a more complex lifecycle of the species compared to that postulated by Mereschkowsky for vagrant taxa. An ITS phylogeny revealed the position of Circinaria tominii relative to three vagrant species, C. alpicola, C. aschabadensis and C. jussufii. Circinaria tominii was first collected in 1926 and was rediscovered in its type locality 90 years later in the only habitat near Ortolyk settlement in the Republic of Altai (Russia). The species is found on soil in stony habitats of the Chuya Steppe. The estimated abundance of the species reaches several hundred specimens.

Resolution of eleven reported and five novel Podaxis species based on ITS phylogeny, phylogenomics, morphology, ecology, and geographic distribution.

The genus Podaxis was first described from India by Linnaeus in 1771, but several revisions of the genus have left the taxonomy unclear. Forty-four Podaxis species names and nine intraspecific varieties are currently accepted, but most fungarium specimens are labelled Podaxis pistillaris. Recent molecular analyses based on barcoding genes suggest that the genus comprises several species, but their status is largely unresolved. Here we obtained basidiospores and photographs from 166 fungarium specimens from around the world and generated a phylogeny based on rDNA internal transcribed spacer ITS1,5.8S and ITS2 (ITS), and a phylogenomic analysis of 3 839 BUSCO genes from low-coverage genomes for a subset of the specimens. Combining phylogenetics, phylogenomics, morphology, ecology, and geographical distribution, spanning 250 years of collections, we propose that the genus includes at least 16 unambiguous species. Based on 10 type specimens (holotype, paratype, and syntype), four recorded species were confirmed, P. carcinomalis, P. deflersii, P. emerici, and P. farlowii. Comparing phylogenetic analysis with described species, including morphology, ecology, and distribution, we resurrected P. termitophilus and designated neotypes, epitypes, or lectotypes for five previously described species, P. aegyptiacus, P. africana, P. beringamensis, P. calyptratus, and P. perraldieri. Lastly, based on phylogenies and morphology of type material, we synonymized three reported species, P. algericus, P. arabicus, and P. rugospora with P. pistillaris, and described five new species that we named P. desolatus, P. inyoensis, P. mareebaensis, P. namaquensis, and P. namibensis. Citation: Li GS, Leal-Dutra CA, Cuesta-Maté A, et al. 2023. Resolution of eleven reported and five novel Podaxis species based on ITS phylogeny, phylogenomics, morphology, ecology, and geographic distribution. Persoonia 51: 257-279. doi: 10.3767/persoonia.2023.51.07.

Resurrection of the genus Camelinopsis (Brassicaceae, tribe Thlaspideae); with introduction of a new species

The ditypic genus Camelinopsis was recently subsumed into Pseudocamelina. However, we here show that the type species of the genus, Camelinopsis campylopoda is distinct from Pseudocamelina, and should be recognized as a separate genus. The second species C. kurdica, however belongs to the genus Pseudocamelina. Camelinopsis differs from Pseudocamelina mainly by its subglobose to broadly obovoid, slightly flattened silicle which is 1.8–2.6 mm wide, instead of a linear, narrowly ellipsoid, occasionally oblong to obovoid silique, that is never wider than 1.5 mm. In addition, seeds of Camelinopsis are mucilaginous when wetted while seeds of Pseudocamelina are not. A new species of Camelinopsis is also described and illustrated based on new collections from western Alborz Mountains, northern Iran. This novelty, C. alborzica, is readily distinguished from C. campylopoda by its biennial (versus annual) habit, straight (versus strongly flexuous) racemes, longer sepals (1.7–2.1 versus 1.2–1.5 mm), shorter fruiting pedicels (0.5–1 versus 1.5– 4 cm) and higher ovule number (8 versus 4 per ovary). The genus Camelinopsis is considered a low mountain relative of the high‐elevation genus Didymophysa, as indicated by an ITS phylogeny.

Morphological and molecular analysis of Ephydatia fluviatilis (Porifera: Spongillida: Spongillidae) from Nanjing, China

We present a comprehensive morphological description of Ephydatia fluviatilis collected in Nanjing for the first time in studies of freshwater sponges in China, based on scanning electron micrography of the sponge meshwork, the megascleres, the gemmules, and the delicate gemmuloscleres, in comparison with relevant data reported worldwide. The morphotype revealed in this study shows a peculiar spicular complement of the skeleton composed of two types of megascleres (the normal oxeas and occasional styles) with abundant tiny, centrally distributed microspinoses, gemmules (ca. 440 μm in diameter) bearing two types of spinose decoration on the shaft (i.e., erect long spines and microspinoses). We report the first complete ITS sequences of the morphotype of E. fluviatilis from China, which, combined with homologous sequences of related taxa from GenBank, are used in a phylogenetic analysis in order to understand the species relationship within Ephydatia and neighbouring taxa. Combining the ITS phylogeny and the gemmulosclere morphotypes, we identify three clades in the paraphyletic genus Ephydatia that are distinguished by different birotule gemmulosclere morphotypes for gemmule-bearing species. Multiple losses of gemmules within endemic taxa, as previously proposed, are confirmed in this study in a phylogenetic context obtained herein. Additionally, genetic similarities are found in some morphologically diverse species, likely indicating recent endemism leading to morphological specialization. Considering the diverse fossil record of Ephydatia from Cenozoic sedimentary strata of wide geographic ranges, we hypothesize that Ephydatia might have a deep root in the Paleogene or earlier and experienced a rapid, Quaternary radiation with emergences of specialized endemic species that lost gemmules under glacial-interglacial paleoenvironment.

Discovery and structural assignment of (S)-sydosine from amphipod-derived Aspergillus sydowii MBC15-11F through HRMS, advanced Mosher, and molecular modelling analyses.

This study aims to prioritize fungal strains recovered from under-explored habitats that produce new metabolites. HRMS dereplication is used to avoid structure redundancy, and molecular modelling is used to assign absolute configuration. MBC15-11F was isolated from an amphipod and identified using ITS, 28S, and β-tubulin phylogeny as Aspergillus sydowii. Chemical profiling using taxonomic-based dereplication identified structurally diverse metabolites, including unreported ones. Large-scale fermentation led to the discovery of a new N-acyl adenosine derivative: (S)-sydosine (1) which was elucidated by NMR and HRESIMS analyses. Two known compounds were also identified as predicted by the initial dereplication process. Due to scarcity of 1, molecular modelling was used to assign its absolute configuration without hydrolysis, and is supported by advanced Mosher derivatization. When the isolated compounds were assessed against a panel of bacterial pathogens, only phenamide (3) showed anti-Staphylococcus aureus activity. Fermentation of A. sydowii yielded a new (S)-sydosine and known metabolites as predicted by HRESIMS-aided dereplication. Molecular modelling prediction of the absolute configuration of 1 agreed with advanced Mosher analysis.

Survivors from a Pliocene Climatic Catastrophe: Gyrodactylus (Platyhelminthes, Monogenea) Parasites of the Relict Fishes in the Central Asian Internal Drainage Basin of Mongolia

We investigated the Gyrodactylus ectoparasites on relict fishes in the isolated endorheic Central Asian Internal drainage basin in Mongolia (The Hollow) and placed them into the global phylogenetic framework based on internal transcribed spacer regions of the nuclear ribosomal DNA (ITS). Much of the rich Pliocene lacustrine ichthyofauna is extinct. We sampled five riverine survivors: Altai osmans Oreoleuciscus humilis and O. potanini (Leuciscidae), Mongolian grayling Thymallus brevirostris (Salmonidae), and stone loaches Barbatula conilobus and B. cobdonensis (Nemacheilidae). We found eight species of the subgenus Gyrodactylus (Limnonephrotus) and four of G. (Gyrodactylus). Nine species were identified as taxa described earlier, and three were described as new. The endemic Mongolian grayling carried four species, only one of wageneri group typical to salmonids (Gyrodactylus radimi sp. nov.), two of nemachili group (G. zavkhanensis sp. nov., G. pseudonemachili Ergens and Bychowsky, 1967), and G. amurensis Akhmerov, 1952 of subgenus G. (Gyrodactylus). G. pseudonemachili was also found on osman and loach. A parasite clade typical for Nemacheilidae was overrepresented by five species (G. tayshirensis sp. nov. on Barbatula conilobus, G. mongolicus Ergens and Dulmaa, 1970, G. nemachili Bychowsky, 1936). Relaxed host specificity mentioned already by Ergens and Dulmaa was evident. In the updated global ITS phylogenies of the two freshwater-restricted subgenera, the parasites from the Mongolian relict populations assumed positions concordant with a hypothesis of multiple ancient introductions from the Euro-Siberian fauna, strong rarefaction and three cases of endemic divergence.

Physiological changes in tomato colonized by dark septate endophytic fungi

As is customary in mycorrhizae, the interaction between plant and dark septate endophytic (DSE) fungi can result in physiological changes in the host plant, which are still poorly understood. This study aimed to evaluate the physiological changes in tomato plants colonized by DSE fungi. Four DSE isolates previously identified through ITS phylogeny were inoculated on tomato seeds and compared to non-inoculated plants (control). Kinetic parameters (Vmax and Km) were calculated measuring the nitrate content in the nutrient solution. The contents of NO3--N, NH4+-N, amino-N, soluble sugars in the root, petiole, stem and leaf, and the contents of macronutrients in the shoot were determined. The plants inoculated with A101 and A105 exhibited (i) significant increases in the soluble sugar contents; (ii) increases in the contents of P, K, Mg and S; and (iii) increased dry biomass compared to control. The A103 inoculation was antagonistic when compared to the other treatments, leading to a higher influx of NO3--N in the plants, resulting in a higher amino-N and the lower soluble sugar content in the shoot. The physiological parameters of tomato varied depending on the inoculation, and the changes ranged from positive to negative depending on each isolate involved in the interaction.

Endophytic Fusarium proliferatum Reprogrammed Phytohormone Production and Antioxidant System of Oryza sativa under Drought Stress

The aim of the current study was to isolate endophytes from the roots of Rhazya stricta and assess their potential to improve the growth of drought-stressed sunflower seedlings. The potential role of the isolated endophytic fungus was initially screened by using two rice varieties (mutant rice cultivar Waito-C: Gibberellins deficient; and Dongji byeo: Gibberellins-producing normal cultivar). A significant (p < 0.05) increase in various growth attributes of both rice varieties associated with one of the isolates i.e., N4 was noticed. Furthermore, the N4 isolate was tested for its role in improving the agronomic attributes of sunflowers under drought stress. The symbiotic association significantly (p < 0.05) improved the host growth and protection from PEG-induced drought stress. The drought mitigation in N4-associated sunflower seedlings can be linked with the regulation of phytohormones, stress-related metabolites, low-molecular-weight proteins and sugars, and scavenging of reactive oxygen species (ROS). Microscopic analysis revealed that the potent endophytic fungal strain consisted of thin and hyaline hyphae, forming dense olive-green mycelia (4–5 cm in dm) with black flask-shaped fruiting bodies. Based on the ITS sequence homology and phylogeny, the strain was identified as Fusarium proliferatum (MG251448). The results of this study concluded that this phytohormone-secreting endophyte can improve crop productivity in dry areas where drought stress is the main challenge faced by crops.

Taxonomy of Thelidiumauruntii and T.incavatum complexes (lichenized Ascomycota, Verrucariales) in Finland.

The taxonomy of lichen species morphologically similar to Thelidiumauruntii and T.incavatum in Finland is being revised. Based on ITS and morphology, ten species occur in Finland. All species are restricted to calcareous rocks. The Thelidiumauruntii morphocomplex includes six species: T.auruntii, T.huuskoneniisp. nov., T.pseudoauruntiisp. nov., T.sallaense sp. nov, T.toskalharjiensesp. nov. and T. sp. 1. In the ITS phylogeny, T.auruntii, T.pseudoauruntii and T.sallaense group together, but the remaining species are placed outside of this clade. All the species have northern distribution in Finland, occurring on fells in NW Finland and/or in gorges in the Oulanka area in NE Finland. The Thelidiumincavatum morphocomplex includes four species: T.declivumsp. nov., T.incavatum, T.mendaxsp. nov. and T. sp. 2. This morphogroup is not resolved as monophyletic in the ITS phylogeny, with only T.declivum and T.mendax forming a strongly supported group. Thelidiumincavatum is rather common in SW Finland, with one separate locality in eastern Finland. Thelidiumdeclivum occurs only in the Oulanka area. Thelidiummendax occurs in the Oulanka area, but one locality is known from eastern central Finland. Thelidium sp. 2 is known from one locality in SW Lapland.

Two new chasmophytic species of Silene (Caryophyllaceae, sect. Siphonomorpha) from Iran

Based on morphological and molecular evidence, two new species of Silene are recognized and described here, S. penduliflora F.Jafari, Keshavarzi & Doostm. sp. nov. and S. thyrsiantha F.Jafari, Mirtadz. & Keshavarzi sp. nov. The newly discovered species are distributed in the central and southeastern parts of Iran, growing in rocky habitats. Relationships among these species and their close relatives are demonstrated using nrDNA ITS and cpDNA rps16 phylogenies. Silene ghahremaninejadii, S. parrowiana, and S. shahrudensis form a clade with these new species. A key to S. penduliflora and S. thyrsiantha and their close relatives is provided.

Symbiotic and toxinogenic Rhizopus spp. isolated from soils of different papaya producing regions in Mexico.

Mucoralean fungi from the genus Rhizopus are common inhabitants of terrestrial ecosystems, being some pathogens of animals and plants. In this study, we analyzed the symbiotic and toxinogenic potential of Rhizopus species derived from agricultural soils dedicated to the production of papaya (Carica papaya L.) in Mexico. Four representative strains of soil-derived Rhizopus spp. were analyzed employing molecular, microscopic, and metabolic methods. The ITS phylogenies identified the fungi as Rhizopus microsporus HP499, Rhizopus delemar HP475 and HP479, and Rhizopus homothallicus HP487. We discovered that R. microsporus HP499 and R. delemar HP475 harbor similar endofungal bacterial symbionts that belong to the genus Mycetohabitans (Burkholderia sensu lato) and that none of the four fungi were associated with Narnavirus RmNV-20S and RmNV-23S. Intriguingly, the interaction between R. delemar - Mycetohabitans showed different phenotypes from known R. microsporus - Mycetohabitans symbioses. Elimination of bacteria in R. delemar HP475 did not cause a detrimental effect on fungal growth or asexual reproduction. Moreover, metabolic and molecular analyses confirmed that, unlike symbiotic R. microsporus HP499, R. delemar HP475 does not produce rhizoxin, one of the best-characterized toxins produced by Mycetohabitans spp. The rhizoxin (rhi) biosynthetic gene cluster seems absent in this symbiotic bacterium. Our study highlights that the symbioses between Rhizopus and Mycetohabitans are more diverse than anticipated. Our findings contribute to expanding our understanding of the role bacterial symbionts have in the pathogenicity, biology and evolution of Mucorales.

A phylogenetic perspective of antiviral species of the genus Artemisia (Asteraceae-Anthemideae): A proposal of anti SARS-CoV-2 (COVID-19) candidate taxa

IntroductionDifferent classes of disease-causing viruses are widely distributed universally. Plant-based medicines are anticipated to be effective cures for viral diseases including the COVID-19, instigated by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). This study displays the phylogenetic perspective of Artemisia and proposes some candidate taxa against different viral diseases, including SARS-CoV-2. MethodsData of Artemisia with antiviral activity were obtained from different published sources and electronic searches. A phylogenetic analysis of the nrDNA ITS sequences of reported antiviral Artemisia species, along with the reference species retrieved from the NCBI GenBank database, was performed using the maximum likelihood (ML) approach. ResultsIn total, 23 Artemisia species have been documented so far with antiviral activity for 17 different types of viral diseases. 17 out of 23 antiviral Artemisia species were included in the ITS phylogeny, which presented the distribution of these antiviral Artemisia species in clades corresponding to different subgenera of the genus Artemisia. In the resultant ML tree, 10 antiviral Artemisia species appeared within the subgenus Artemisia clade, 2 species appeared within the subgenus Absinthium clade, 3 species appeared within the subgenus Dracunculus clade, and 2 species appeared within the subgenus Seriphidium clade. DiscussionArtemisia species from different subgenera with antiviral activity are prevalent in the genus, with most antiviral species belonging to the subgenus Artemisia. A detailed analysis of taxa from all subgenera, particularly the subgenus Artemisia, is therefore proposed in order to discover compounds with potential anti-SARS-CoV-2 activity.

A Molecular Systematics and Taxonomy Research on Trechispora (Hydnodontaceae, Trechisporales): Concentrating on Three New Trechispora Species from East Asia.

Trechispora are an important genus of wood-inhabiting fungi that have the ability to decompose rotten wood in the forest ecosystem. In this study, we reported three new species of Trechispora: T. murina, T. odontioidea, T. olivacea from a subtropical region of Yunnan Province, China. Species descriptions were based on a combination of morphological features and phylogenetic analyses of the ITS and LSU region of nuclear ribosomal DNA. Trechispora murina is characterized by the resupinate basidiomata, grandinioid hymenial surface with a greyish tint, monomitic hyphal system and ellipsoid, thick-walled, ornamented basidiospores; T. odontioidea has an odontioid hymenial surface with cylindrical to conical, blunt aculei and subglobose to globose, colorless, slightly thick-walled, ornamented basidiospores; T. olivacea has a farinaceous hymenial surface with olivaceous tint, basidia clavate and thick-walled, ornamented, broadly ellipsoid to globose basidiospores. Sequences of the ITS and nLSU rDNA markers of the studied samples were generated, and phylogenetic analyses were performed with maximum likelihood, maximum parsimony, and Bayesian inference methods. After a series of phylogenetic analyses, the 5.8S+nLSU dataset was constructed to test the phylogenetic relationship of Trechispora with other genera of Hydnodontaceae. The ITS dataset was used to evaluate the phylogenetic relationship of the three new species with other species of Trechispora. Using ITS phylogeny, the new species T. murina was retrieved as a sister to T. bambusicola with moderate supports; T. odontioidea formed a single lineage and then grouped with T. fimbriata and T. nivea; while T. olivacea formed a monophyletic lineage with T. farinacea, T. hondurensis, and T. mollis.

Molecular, morphological and chemical variation of the Usnea pectinata aggregate from Tanzania, São Tomé and Príncipe

AbstractThis study investigated the molecular, chemical and morphological variation in the Usnea pectinata aggregate using 42 specimens, 22 from Tanzania and 20 from São Tomé and Príncipe. A total of 31 sequences (13 ITS, 13 nuLSU and 5 RPB1) were generated. The results are presented in two phylogenies: first a three-markers ‘backbone’ phylogeny for the U. pectinata aggregate, where six distinct, strongly supported subclades indicate considerable genetic variation in the dataset; and second, an ITS phylogeny with 47 terminals along with a mapping of morphological and chemistry data. Several well-supported monophyletic clades were recovered in both phylogenies and these may well represent separate species in the complex referred to here as the U. pectinata aggregate. Three morphotypes characterized by axis pigmentation and four by branch shape were noted. Six chemotypes were observed.

A Revised Phylogenetic Classification for Viola (Violaceae).

The genus Viola (Violaceae) is among the 40–50 largest genera among angiosperms, yet its taxonomy has not been revised for nearly a century. In the most recent revision, by Wilhelm Becker in 1925, the then-known 400 species were distributed among 14 sections and numerous unranked groups. Here, we provide an updated, comprehensive classification of the genus, based on data from phylogeny, morphology, chromosome counts, and ploidy, and based on modern principles of monophyly. The revision is presented as an annotated global checklist of accepted species of Viola, an updated multigene phylogenetic network and an ITS phylogeny with denser taxon sampling, a brief summary of the taxonomic changes from Becker’s classification and their justification, a morphological binary key to the accepted subgenera, sections and subsections, and an account of each infrageneric subdivision with justifications for delimitation and rank including a description, a list of apomorphies, molecular phylogenies where possible or relevant, a distribution map, and a list of included species. We distribute the 664 species accepted by us into 2 subgenera, 31 sections, and 20 subsections. We erect one new subgenus of Viola (subg. Neoandinium, a replacement name for the illegitimate subg. Andinium), six new sections (sect. Abyssinium, sect. Himalayum, sect. Melvio, sect. Nematocaulon, sect. Spathulidium, sect. Xanthidium), and seven new subsections (subsect. Australasiaticae, subsect. Bulbosae, subsect. Clausenianae, subsect. Cleistogamae, subsect. Dispares, subsect. Formosanae, subsect. Pseudorupestres). Evolution within the genus is discussed in light of biogeography, the fossil record, morphology, and particular traits. Viola is among very few temperate and widespread genera that originated in South America. The biggest identified knowledge gaps for Viola concern the South American taxa, for which basic knowledge from phylogeny, chromosome counts, and fossil data is virtually absent. Viola has also never been subject to comprehensive anatomical study. Studies into seed anatomy and morphology are required to understand the fossil record of the genus.

Molecular and morphological diversity in the /Rhombisporum clade of the genus Entoloma with a note on E. cocles

A combined morphological and molecular genetic study of the European species within the /Rhombisporum clade of the genus Entoloma reveals a high species diversity. This group comprises typical grassland species with pronounced and well-differentiated cheilocystidia, and a wide range of spore shapes varying from rhomboid to five-angled. To fix the concept of the classical species E. rhombisporum, a neotype is designated. Nine species are described as new to science based on the result of nrDNA ITS phylogeny with additional gap coding, and morphological characterization: E. caulocystidiatum, E. lunare, E. pararhombisporum, E. pentagonale, E. perrhombisporum, E. rhombiibericum, E. rhombisporoides, E. sororpratulense, and E. subcuboideum. The ITS sequences of the holotypes of previously described species belonging to the /Rhombisporum clade, viz., E. laurisilvae and E. pratulense have also been generated and are published here for the first time. Since many of the above-mentioned species have been misidentified as E. cocles, it seemed opportune to also study this species and to designate a neotype to fix its current concept. A key including European species is presented. As most of the species are potentially important indicators for threatened grassland communities, the 130 ITS barcodes newly generated for this study may be useful as a reference in conservation and metabarcoding projects.

Polyphasic Identification and Genomic Insights of Leptothermofonsia sichuanensis gen. sp. nov., a Novel Thermophilic Cyanobacteria Within Leptolyngbyaceae

Thermal environments are an important reservoir of thermophiles with significant ecological and biotechnological potentials. However, thermophilic isolates remain largely unrecovered from their habitats and are rarely systematically identified. In this study, we characterized using polyphasic approaches a thermophilic strain, PKUAC-SCTAE412 (E412 hereafter), recovered from Lotus Lake hot spring based in Ganzi prefecture, China. The results of 16S rRNA/16S-23S ITS phylogenies, secondary structure, and morphology comparison strongly supported that strain E412 represent a novel genus within Leptolyngbyaceae. This delineation was further confirmed by genome-based analyses [phylogenomic inference, average nucleotide/amino-acid identity, and the percentages of conserved proteins (POCP)]. Based on the botanical code, the isolate is herein delineated as Leptothermofonsia sichuanensis gen. sp. nov, a genus adjacent to recently delineated Kovacikia and Stenomitos. In addition, we successfully obtained the first complete genome of this new genus. Genomic analysis revealed its adaptations to the adverse hot spring environment and extensive molecular components related to mobile genetic elements, photosynthesis, and nitrogen metabolism. Moreover, the strain was capable of modifying the composition of its light-harvesting apparatus depending on the wavelength and photoperiod, showing chromatic adaptation capacity characteristic for T1 and T2 pigmentation types. Other physiological studies showed the strain’s ability to utilize sodium bicarbonate and various sulfur compounds. The strain was also shown to be diazotrophic. Interestingly, 24.6% of annotated protein-coding genes in the E412 genome were identified as putatively acquired, hypothesizing that a large number of genes acquired through HGT might contribute to the genome expansion and habitat adaptation of those thermophilic strains. Most the HGT candidates (69.4%) were categorized as metabolic functions as suggested by the KEGG analysis. Overall, the complete genome of strain E412 provides the first insight into the genomic feature of the genus Leptothermofonsia and lays the foundation for future global ecogenomic and geogenomic studies.