RESUMEN
We report discovery of a new bacterial genus and species of the family Pasteurellaceae by using phylogenetic and metabolic analysis. The bacterium, Emayella augustorita, was isolated from blood cultures of a patient in France diagnosed with an adenocarcinoma of the intestines and who was treated with a biliary prosthesis placement.
Asunto(s)
Cultivo de Sangre , Infecciones por Pasteurellaceae , Pasteurellaceae , Filogenia , Sepsis , Humanos , Pasteurellaceae/aislamiento & purificación , Pasteurellaceae/genética , Pasteurellaceae/clasificación , Infecciones por Pasteurellaceae/microbiología , Infecciones por Pasteurellaceae/diagnóstico , Sepsis/microbiología , Sepsis/diagnóstico , ARN Ribosómico 16S/genética , Masculino , Antibacterianos/uso terapéutico , Antibacterianos/farmacología , Bacteriemia/microbiología , Bacteriemia/diagnóstico , Francia , AncianoRESUMEN
An acid-neutralizing, filamentous, non-heterocytous, marine cyanobacterium named 'LK' has been isolated from the seashore of Bangaram Island, an atoll of Lakshadweep, India, and is described here as a novel species. LK has been characterized using morphological, ecological, and genomic features. Based on 16S rRNA, whole-genome sequencing, and marker gene-based analysis, LK has been identified as a new species. LK clustered with Leptolyngbya-like strains belonging to the LPP group but diverged from Leptolyngbya sensu stricto, indicating the polyphyletic nature of the Leptolyngbya genus. Leptolyngbya sp. SIOISBB and Halomicronema sp. CCY15110 were identified as LK's two closest phylogenetic neighbors in various phylogenetic studies. The analysis of 16S rRNA, ITS secondary structures, and genome relatedness indices such as AAI, ANI, and gANI strongly support LK as a novel species of the Leptolyngbya genus. The mechanism behind acid neutralization in LK has been delineated, attributing it to a surface phenomenon most likely due to the presence of salts of calcium, magnesium, sodium, and potassium. We name LK as Leptolyngbya iicbica strain LK which is a novel species with prominent acidic pH-neutralizing properties.
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Cianobacterias , Filogenia , ARN Ribosómico 16S , Cianobacterias/genética , Cianobacterias/clasificación , ARN Ribosómico 16S/genética , India , Islas , ADN Bacteriano/genética , Agua de Mar/microbiología , Genoma Bacteriano/genética , Análisis de Secuencia de ADNRESUMEN
Fern-spore-feeding (FSF) is rare and found in only four families of Lepidoptera. Stathmopodidae is the most speciose family that contains FSF species, and its subfamily Cuprininae exclusively specializes on FSF. However, three species of Stathmopodinae also specialize on FSF. To better understand the evolutionary history of FSF and, more generally, the significance of specialization on a peculiar host, a phylogenetic and taxonomic revision for this group is necessary. We reconstructed the most comprehensive molecular phylogeny, including one mitochondrial and four nuclear genes, of Stathmopodidae to date, including 137 samples representing 62 species, with a particular focus on the FSF subfamily, Cuprininae, including 33 species (41% of named species) from 6 of the 7 Cuprininae genera. Species from two other subfamilies, Stathmopodinae and Atkinsoniinae, were also included. We found that FSF evolved only once in Stathmopodidae and that the previous hypothesis of multiple origins of FSF was misled by inadequate taxonomy. Moreover, we showed that (1) speciation/extinction rates do not differ significantly between FSF and non-FSF groups and that (2) oligophage is the ancestral character state in Cuprininae. We further revealed that a faster rate of accumulating specialists over time, and thus a higher number of specialists, was achieved by a higher transition rate from oligophagages to specialists compared to the transition rate in the opposite direction. We finish by describing three new genera, Trigonodagen. nov., Petalagen. nov., and Pediformisgen. nov., and revalidating five genera: Cuprina, Calicotis, Thylacosceles, Actinoscelis, Thylacosceloides in Cuprininae, and we provide an updated taxonomic key to genera and a revised global checklist of Cuprininae.
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Helechos , Lepidópteros , Animales , Lepidópteros/genética , Filogenia , Insectos , EsporasRESUMEN
Although numerous studies have been conducted on hybrid speciation, our understanding of this process remains limited. Through an 18-year systematic investigation of all taxa of Populus on the Qinghai-Tibet Plateau, we discovered three new taxa with clear characteristics of sect. Leucoides. Further evidence was gathered from morphology, whole-genome bioinformatics, biogeography, and breeding to demonstrate synthetically that they all originated from distant hybridization between sect. Leucoides and sect. Tacamahaca. P. gonggaensis originated from the hybridization of P. lasiocarpa with P. cathayana, P. butuoensis from the hybridization of P. wilsonii with P. szechuanica, and P. dafengensis from the hybridization of P. lasiocarpa with P. szechuanica. Due to heterosis, the three hybrid taxa possess greater ecological adaptability than their ancestral species. We propose a hybrid speciation process model that incorporates orthogonal, reverse, and backcrossing events. This model can adequately explain some crucial evolutionary concerns, such as the nuclear-cytoplasmic conflict on phylogeny and the extinction of ancestral species within the distribution range of hybrid species.
Asunto(s)
Populus , Filogenia , Populus/genética , Evolución Biológica , Hibridación Genética , Hibridación de Ácido NucleicoRESUMEN
A Gram-stain-negative, aerobic, rod-shaped and motile strain HL-JVS1T, was isolated from the gastric tract of a juvenile Pacific white shrimp. Molecular phylogenetic analysis based on 16S rRNA gene sequences of strain HL-JVS1T revealed its affiliation with the genus Pleionea, with close relatives including Pleionea mediterranea MOLA115T (97.5%) and Pleionea sediminis S1-5-21T (96.2%). The complete genome of strain HL-JVS1T consisted of a circular 4.4 Mb chromosome and two circular plasmids (6.6 and 35.0 kb) with a G + C content of 43.1%. The average nucleotide identity and digital DNA-DNA hybridization values between strain HL-JVS1T and the type strains of described Pleionea species were 69.7-70.4% and 18.3-18.6%, respectively. Strain HL-JVS1T grew at 10-40 °C (optimum, 30 °C) in the presence of 0.5 - 9.0% (w/v) sea salts (optimum, 2.0 - 2.5%), and at pH range of 5.5 - 10.0 (optimum, pH 6.5). The major fatty acids (> 10%) were summed feature 9 (iso-C17:1 ω9c and/or C16:0 10-methyl) (23.3%), iso-C16:0 (14.5%), iso-C11:0 3-OH (13.8%) and iso-C15:0 (11.0%). The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminophospholipid, two unidentified aminolipids, and two unidentified lipids. The respiratory quinone was ubiquinone-8. The comprehensive phylogenetic, phylogenomic, phenotypic and chemotaxonomic results showed that strain HL-JVS1T is distinct from other Pleionea species. Hence, we propose strain HL-JVS1T as a novel species belonging to the genus Pleionea, for which the name Pleionea litopenaei sp. nov. is proposed with HL-JVS1T (= KCCM 90514T = JCM 36490T) as the type strain.
Asunto(s)
Composición de Base , ADN Bacteriano , Ácidos Grasos , Penaeidae , Filogenia , ARN Ribosómico 16S , Animales , ARN Ribosómico 16S/genética , Ácidos Grasos/análisis , Ácidos Grasos/metabolismo , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Hibridación de Ácido Nucleico , Análisis de Secuencia de ADN , Genoma Bacteriano , Planococcaceae/genética , Planococcaceae/aislamiento & purificación , Planococcaceae/clasificación , Tracto Gastrointestinal , Fosfolípidos/análisisRESUMEN
During investigations of invertebrate-associated fungi in Yunnan Province of China, a new species, Sporodiniella sinensis sp. nov., was collected. Morphologically, S. sinensis is similar to Sporodiniella umbellata; however, it is distinguished from S. umbellata by its greater number of sporangiophore branches, longer sporangiophores, larger sporangiospores, and columellae. The novel species exhibits similarities of 91.62â% for internal transcribed spacer (ITS), 98.66-99.10â% for ribosomal small subunit (nrSSU), and 96.36-98.22â% for ribosomal large subunit (nrLSU) sequences, respectively, compared to S. umbellata. Furthermore, phylogenetic analyses based on combined sequences of ITS, nrLSU and nrSSU show that it forms a separate clade in Sporodiniella, and clusters closely with S. umbellata with high statistical support. The phylogenetic and morphological evidence support S. sinensis as a distinct species. Here, it is formally described and illustrated, and compared with other relatives.
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Ácidos Grasos , Mucorales , Animales , Filogenia , China , Análisis de Secuencia de ADN , Composición de Base , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Ácidos Grasos/química , InvertebradosRESUMEN
A novel Gram-stain-negative, facultatively anaerobic and rod-shaped bacterial strain, designated as DAU312T, was isolated from the sea water of the eastern coast of the Republic of Korea. Optimal growth was observed at 25â°C, pH 7.0-8.0 and with NaCl concentrations of 2.0â% (w/v). Catalase and oxidase activities were detected. On the basis of 16S rRNA gene sequences, strain DAU312T showed the highest similarity (99.2â%) to the type strain Shewanella electrodiphila MAR441T. The complete genome sequence of strain DAU312T contains 4â893â483 bp and 40.5âmol% G+C. Phylogenetic analyses based on 16S rRNA gene sequences and the up-to-date bacterial core genes showed that strain DAU312T, S. electrodiphila MAR441T and S. olleyana were all part of the same monophyletic clade. Their average nucleotide identity, digital DNA-DNA hybridization and two-way average amino acid identity values with each other and type strains of close Shewanella species were 83.4-77.5â%, 27.3-22.0â% and 89.8-81.2â%, respectively. The major cellular fatty acids (>10â%) were iso-C15â:â0, summed feature 3 (C16â:â1 ω7Ñ and/or C16â:â1 ω6Ñ) and C16â:â0. Phosphatidylethanolamine and phosphatidylglycerol were the main polar lipids. The respiratory quinones were Q-7, Q-8, MK-7 and MMK-7. Based on these polyphasic taxonomic findings, the name Shewanella goraebulensis sp. nov. is suggested for strain DAU312T, which is considered to represent a novel species of the genus Shewanella. The type strain is DAU312T (=KCTC 72427 T=JCM 35744T=KCCM 43478T).
Asunto(s)
Ácidos Grasos , Agua de Mar , Ácidos Grasos/química , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Composición de BaseRESUMEN
An aerobic, Gram-stain-negative and short rod-shaped bacterial strain, designated M6-31T, was isolated from rice paddy soil sampled in Miryang, Republic of Korea. Growth was observed at 4-35â°C (optimum, 28â°C), pH 6.0-9.0 (optimum, pH 7.0-8.0) and in the presence of 0-4â% (w/v) NaCl (optimum, 0â% w/v). Phylogenetic analysis based on 16S rRNA gene sequences grouped strain M6-31T with Sphingobacterium bambusae IBFC2009T, Sphingobacterium griseoflavum SCU-B140T and Sphingobacterium solani MLS-26-JM13-11T in the same clade, with the 16S rRNA gene sequence similarities ranging from 95.8 to 96.6â%. A genome-based phylogenetic tree reconstructed by using all publicly available Sphingobacterium genomes placed strain M6-31T with S. bambusae KACC 22910T, 'Sphingobacterium deserti' ACCC 05744T, S. griseoflavum CGMCC 1.12966T and Sphingobacterium paludis CGMCC 1.12801T. Orthologous average nucleotide identity and digital DNA-DNA hybridization values between strain M6-31T and its closely related strains were lower than 74.6 and 22.0â%, respectively. The respiratory quinone was menaquinone-7, and the major polar lipid was phosphatidylethanolamine. The major fatty acids (>10â%) were C15â:â0 iso, C17â:â0 iso 3OH and summed feature 3. The phenotypic, chemotaxonomic and genotypic data obtained in this study showed that strain M6-31T represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium oryzagri sp. nov. (type strain M6-31T=KACC 22765T=JCM 35893T) is proposed.
Asunto(s)
Técnicas de Tipificación Bacteriana , ADN Bacteriano , Ácidos Grasos , Hibridación de Ácido Nucleico , Oryza , Filogenia , ARN Ribosómico 16S , Análisis de Secuencia de ADN , Microbiología del Suelo , Sphingobacterium , Vitamina K 2 , Vitamina K 2/análogos & derivados , Oryza/microbiología , ARN Ribosómico 16S/genética , Ácidos Grasos/química , Sphingobacterium/genética , Sphingobacterium/aislamiento & purificación , Sphingobacterium/clasificación , ADN Bacteriano/genética , República de Corea , Vitamina K 2/análisis , Composición de Base , FosfatidiletanolaminasRESUMEN
Two cocci-shaped, facultatively anaerobic, Gram-positive bacteria isolated from the faeces of a pig were designated as strains YH-aer221T and YH-aer222. Analysis of the 16S rRNA gene sequences revealed that the isolates were most closely related to Aerococcus suis JCM 18035T with 96.6â% similarity. The multi-locus sequence tree revealed that the isolates formed a sub-cluster adjacent to A. suis JCM 18035T. The average nucleotide identity values for the isolates and their most closely related strains were 71.8 and 71.7â%, respectively; and the digital DNA-DNA hybridization values for the isolates and their most closely related strains were 25.6 and 25.5â%, respectively. The main fatty acids were C18â:â1ω9c, C16â:â0 and C18â:â0. The cell wall contained the meso-diaminopimelic acid-based peptidoglycan. The two isolates shared the same metabolic pathways. Isolates YH-aer221T and YH-aer222 harboured the same CRISPR array with 33 and 46 spacers, respectively. Single-genome vs. metagenome analysis showed that the genomes of the isolates were not found in the available metagenome database. Given their chemotaxonomic, phenotypic and phylogenetic properties, YH-aer221T (= KCTC 25571T=JCM 35699T) and YH-aer222 (=KCTC 25573=JCM 35700) represent a novel taxon. The name Aerococcus kribbianus sp. nov. is proposed.
Asunto(s)
Aerococcus , Porcinos , Animales , Anaerobiosis , Composición de Base , Ácidos Grasos/química , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Bacterias Anaerobias , HecesRESUMEN
A novel Gram-stain-negative, curved rod-shaped, motile and chitin-degrading strain, designated CD1T, was isolated from crawfish pond sediment in Caidian District (30° 58' N 114° 03' E), Wuhan City, Hubei Province, PR China. Growth of this strain was observed at 15-40°C (optimum between 28 and 30â°C), at pH 7.0-9.0 (optimum between pH 7.0 and 8.0) and with 0-1â% (w/v) NaCl (optimum at 0â%). With respect to the 16S rRNA gene sequences, strain CD1T had the highest similarity (96.91-97.25â%) to four type strains of the genera 'Chitinolyticbacter' and Chitiniphilus within the family Chitinibacteraceae. The phylogenetic trees based on genome sequences and 16S rRNA gene sequences indicated that strain CD1T was close to members of these two genera, in particular to the genus Chitiniphilus. The genomic DNA G+C content of strain CD1T was 64.8 mol%. The average nucleotide identity and the Genome-to-Genome Distance Calculator results showed low relatedness (below 95 and 70â%, respectively) between strain CD1T and the closely related type strains. Ubiquinone-8 was the predominant quinone. The major cellular fatty acids were C10â:â0, C16â:â0, summed feature 3 (C16â:â1 ω7c and/or C16â:â1 ω6c) and summed feature 8 (C18â:â1 ω7c and/or C18â:â1 ω6c). The polar lipid profile was composed of a mixture of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four unidentified lipids, two unidentified phospholipids, two unidentified aminolipids and an unidentified aminoglycolipid. On the basis of the evidences presented in this study, strain CD1T represents a novel species of the genus Chitiniphilus, for which the name Chitiniphilus purpureus sp. nov. is proposed, with strain CD1T (=CCTCC AB 2022395T=KCTC 92850T) as the type strain.
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Betaproteobacteria , Quitina , Filogenia , Estanques , ARN Ribosómico 16S/genética , Composición de Base , Ácidos Grasos/química , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , BacteriasRESUMEN
Four rod-shaped, non-motile, non-spore-forming, facultative anaerobic, Gram-stain-positive lactic acid bacteria, designated as EB0058T, SCR0080, LD0937T and SCR0063T, were isolated from different corn and grass silage samples. The isolated strains were characterized using a polyphasic approach and EB0058T and SCR0080 were identified as Lacticaseibacillus zeae by 16S rRNA gene sequence analysis. Based on whole-genome sequence-based characterization, EB0058T and SCR0080 were separated into a distinct clade from Lacticaseibacillus zeae DSM 20178T, together with CECT9104 and UD2202, whose genomic sequences are available from NCBI GenBank. The average nucleotide identity (ANI) values within the new subgroup are 99.9â% and the digital DNA-DNA hybridization (dDDH) values are 99.3-99.9â%, respectively. In contrast, comparison of the new subgroup with publicly available genomic sequences of L. zeae strains, including the type strain DSM 20178T, revealed dDDH values of 70.2-72.5â% and ANI values of 96.2-96.6â%. Based on their chemotaxonomic, phenotypic and phylogenetic characteristics, EB0058T and SCR0080 represent a new subspecies of L. zeae. The name Lacticaseibacillus zeae subsp. silagei subsp. nov. is proposed with the type strain EB0058T (=DSM 116376T=NCIMB 15474T). According to the results of 16S rRNA gene sequencing, LD0937T and SCR0063T are members of the Lacticaseibacillus group. The dDDH value between the isolates LD0937T and SCR0063T was 67.6â%, which is below the species threshold of 70â%, clearly showing that these two isolates belong to different species. For both strains, whole genome-sequencing revealed that the closest relatives within the Lacticaseibacillus group were Lacticaseibacillus huelsenbergensis DSM 115425 (dDDH 66.5 and 65.9â%) and Lacticaseibacillus casei DSM 20011T (dDDH 64.1 and 64.9â%). Based on the genomic, chemotaxonomic and morphological data obtained in this study, two novel species, Lacticaseibacillus parahuelsenbergensis sp. nov. and Lacticaseibacillus styriensis sp. nov. are proposed and the type strains are LD0937T (=DSM 116105T=NCIMB 15471T) and SCR0063T (=DSM 116297T=NCIMB 15473T), respectively.
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Técnicas de Tipificación Bacteriana , ADN Bacteriano , Ácidos Grasos , Hibridación de Ácido Nucleico , Filogenia , Poaceae , ARN Ribosómico 16S , Análisis de Secuencia de ADN , Ensilaje , Zea mays , ARN Ribosómico 16S/genética , Zea mays/microbiología , Ensilaje/microbiología , ADN Bacteriano/genética , Ácidos Grasos/análisis , Poaceae/microbiología , Composición de Base , Secuenciación Completa del Genoma , LacticaseibacillusRESUMEN
The planktonic dinoflagellate Prorocentrum compressum is widespread in warm and temperate seas. A strain identified as P. cf. compressum BEA 0681B isolated from the island of Gran Canaria, NE Atlantic Ocean, showed a divergence in rDNA/ITS phylogenies with respect to P. compressum. The Canarian strain was oval, with an average length-to-width ratio of 1.35, smooth thecal surface with less than 150 thecal pores, including oblique pores, sometimes with a bifurcated opening. In contrast, P. compressum was rounder, with a length-to-width ratio < 1.2, with reticulate-foveate ornamentation and 200-300 pores per valve. We propose Prorocentrum canariense sp. nov. These species clustered as the most early-branching lineage in the clade Prorocentrum sensu stricto. Although this clade mainly contains planktonic species, the closer relatives were the benthic species P. tsawwassenense and P. elegans. Interestingly, P. compressum and P. canariense sp. nov. are widely distributed in temperate and warm seas without an apparent morphological adaptation to planktonic life. The formation of two concentric hyaline mucilaginous walls could contribute to this success. We discuss the use of Prorocentrum bidens to solve the nomenclature issue of P. compressum that was described citing a diatom as basionym.
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ADN Protozoario , ADN Ribosómico , Dinoflagelados , Filogenia , Dinoflagelados/clasificación , Dinoflagelados/genética , ADN Ribosómico/genética , ADN Protozoario/genética , Océano Atlántico , Análisis de Secuencia de ADN , ADN Espaciador Ribosómico/genética , ADN Espaciador Ribosómico/análisis , Datos de Secuencia MolecularRESUMEN
Chemosynthesis-based ecosystems such as hydrothermal vents and hydrocarbon seeps harbour various endemic species, each uniquely adapted to the extreme conditions. While some species rely on obligatory relationships with bacterial symbionts for nutrient uptake, scavengers and predators also play important roles in food web dynamics in these ecosystems. Acoels, members of the phylum Xenacoelomorpha, are simple, worm-like invertebrates found in marine environments worldwide but are scarcely understood taxa. This study presents a novel genus and species of acoel from a deep-sea hydrocarbon seep off Hatsushima, Japan, Hoftherma hatsushimaensis gen. et sp. nov. Our multi-locus phylogenetic analysis revealed that the acoels are nested within Hofsteniidae, a family previously known exclusively from shallow waters. This finding suggests that at least two independent colonization events occurred in the chemosynthesis-based environments from the phylum Xenoacoelomorpha, represented by hofsteniid acoels and Xenoturbella. Previous reports of hofsteniid species from low-oxygen and sulfide-rich environments, including intertidal habitats with decomposing leaves, in addition to H. hatsushimaensis gen. et sp. nov. from a deep-sea hydrocarbon seep, imply a common ancestral adaptation to sulfide-rich ecosystems within Hofsteniidae. Moreover, the sister relationship between solenofilomorphid acoels predominating in sulfide-rich habitats indicates common ancestral adaptation to sulfide-rich ecosystems between these two families.
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Ecosistema , Invertebrados , Filogenia , Animales , Japón , Invertebrados/clasificación , Respiraderos Hidrotermales/microbiologíaRESUMEN
Geographical distribution plays a major role in our understanding of marine biodiversity. Some marine fish trematodes have been shown to have highly restricted geographical distributions, while some are known to occur over very wide ranges; however, very few of these wide distributions have been demonstrated genetically. Here, we analyse species of the genus Schikhobalotrema (Haplosplanchnidae) parasitizing beloniforms from the tropical west Pacific, the eastern Pacific and the Gulf of Mexico (GoM). We test the boundaries of these trematodes by integrating molecular and morphological data, host association, habitat of the hosts and geographical distribution, following a recently proposed and standardized delineation method for the recognition of marine trematode species. Based on the new collections, Schikhobalotrema huffmani is here synonymized with the type-species of the genus, Schikhobalotrema acutum; Sch. acutum is now considered to be widely distributed, from the GoM to the western Pacific. Additionally, we describe a new species, Schikhobalotrema minutum n. sp., from Strongylura notata and Strongylura marina (Belonidae) from La Carbonera coastal lagoon, northern Yucatán, GoM. We briefly discuss the role of host association and historical biogeography of the hosts as drivers of species diversification of Schikhobalotrema infecting beloniforms.
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Beloniformes , Trematodos , Animales , Golfo de México , Océano Pacífico , Trematodos/genética , BiodiversidadRESUMEN
Cyanobacterial taxonomy is entering the genomic era, but only a few taxonomic studies have employed population genomics, which provides a framework and a multitude of tools to understand species boundaries. Phylogenomic and population genomic analyses previously suggested that several cryptic lineages emerged within the genus Laspinema. Here, we apply population genomics to define boundaries between these lineages and propose two new cryptic species, Laspinema olomoucense and L. palackyanum. Moreover, we sampled soil and puddles across Central Europe and sequenced the 16S rRNA gene and 16S-23S ITS region of the isolated Laspinema strains. Together with database mining of 16S rRNA gene sequences, we determined that the genus Laspinema has a cosmopolitan distribution and inhabits a wide variety of habitats, including freshwater, saline water, mangroves, soil crusts, soils, puddles, and the human body.
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Cianobacterias , Filogenia , ARN Ribosómico 16S , Cianobacterias/genética , Cianobacterias/clasificación , ARN Ribosómico 16S/análisis , ARN Ribosómico 16S/genética , Microbiología del Suelo , Análisis de Secuencia de ADN , ADN Bacteriano/genéticaRESUMEN
Cryptic diversity is common among marine macroalgae, with molecular tools leading to the discovery of many new species. To assign names to these morphologically similar species, the type and synonyms have to be examined, and if appropriate, new species must be described. The turf-forming red alga Polysiphonia scopulorum was originally described from Rottnest Island, Australia, and subsequently widely reported in tropical and temperate coasts based on morphological identifications. A recent study of molecular species delineation revealed a complex of 12 species in Australia, South Africa, and Europe. These species are placed in a taxonomically unresolved lineage of the tribe Polysiphonieae. The aim of this study was to resolve the genus- and species-level taxonomy of this complex and related species using molecular and morphological information. Three morphologically indistinguishable species of the complex were found at the type locality of P. scopulorum, preventing a straightforward assignment of the name to any of the molecular lineages. Therefore, we propose a molecularly characterized epitype. Polysiphonia caespitosa is reinstated for the only species found in its type locality in South Africa. We describe seven new species. Only one species of the complex can be morphologically recognized, with the other eight species indistinguishable based on morphometric analysis. The studied complex, together with another seven species currently placed in Polysiphonia and two Bryocladia species, formed a clade distinct from Polysiphonia sensu stricto. Based on observations of Bryocladia cervicornis (the generitype), we describe our seven new species in the genus Bryocladia and transfer another nine species from Polysiphonia to Bryocladia.
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Algas Comestibles , Rhodophyta , Algas Marinas , Filogenia , Análisis de Secuencia de ADN , Rhodophyta/genéticaRESUMEN
Xenodidymella species have a wide range of hosts and can be found as pathogens and saprobes. In this study, two new species of Xenodidymella were found from leaf diseases of three pasture-medicinal plants in Ilam Province, in the west of Iran, and proposed here as X. ilamica and X. scandicis spp. nov. These species were identified based on morphological features and phylogenetic analyses of the internal transcribed spacer regions 1 & 2 and 5.8S nrDNA (ITS), partial beta-tubulin gene (tub2), and partial RNA polymerase II second largest subunit (rpb2) gene. The four Xenodidymella strains isolated in this study were delimited into two sister clades, with the two isolates of X. ilamica from the leaf spot of Colchicum speciosum and Ficaria kochii and two isolates of X. scandicis from leaf blight of Scandix pecten-veneris. Morphologically, X. scandicis produces larger, ostiolate or poroid pycnidia in vitro, while pycnidia in the cultures of X. ilamica are non-ostiolate and smaller. Some pycnidia in old cultures of X. scandicis produce a neck, but a distinct neck in X. ilamica has not been observed. Moreover, three plants under study are new hosts for the genus Xenodidymella.
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Filogenia , Tubulina (Proteína) , Irán , Tubulina (Proteína)/genética , Plantas Medicinales/microbiología , Enfermedades de las Plantas/microbiología , Hojas de la Planta/microbiología , ADN de Hongos/genética , ARN Polimerasa II/genética , Análisis de Secuencia de ADN , ADN Espaciador Ribosómico/genéticaRESUMEN
Despite the long research history on the genus Coelastrella, its species diversity and biotechnological potential have not been fully explored. For the first time, cluster analysis of morphological characteristics was done in the representatives of the said genus. The results obtained have shown that morphological similarity does not necessarily indicate a molecular genetic relationship. It the light of it, the taxonomic status of species can reliably be determined using specific DNA region, such as 18S-ITS1-5.8S-ITS2. The V4 and V9 regions of gene 18S rRNA are relatively conservative fragments which are not suitable for species identification. The ITS2 can be used as a "short barcode". Among the advanced machine methods for delimitation species, the most effective algorithm for distinguishing Coelastrella species was the Generalized Mixed Yule Coalescent (GMYC) method. This paper represented for the first time our comprehensive review of the works devoted to the analysis of the biotechnological potential of representatives of the genus Coelastrella and shows that fatty acid composition of the three main chemogroups within the studied genus differs. In the future, this may form the basis for predicting the composition of the fatty acid profile of new strains, which is important while searching for organisms with specified biotechnological properties. In conclusion, an integrative approach was employed to describe Coelastrella affinis sp. nov., a new species of the genus Coelastrella with high biotechnological potential. Also, a new description of C. thermophila var. astaxanthina comb. nov. was proposed.
Asunto(s)
Chlorophyceae , Filogenia , ARN Ribosómico 18S , Chlorophyceae/clasificación , Chlorophyceae/genética , ARN Ribosómico 18S/genética , Ácidos Grasos/análisis , Biotecnología , Código de Barras del ADN Taxonómico , ADN de Algas/genética , ADN de Algas/química , Análisis por Conglomerados , Análisis de Secuencia de ADN , ADN Espaciador Ribosómico/genéticaRESUMEN
Nurudea zhengii Ren was identified by aphid morphological characteristics as well as the gall shape and host plant species, and placed in the tribe Fordini (Hemiptera, Aphididae, Eriosomatinae). Here, its whole genome was firstly sequenced by a genome-skimming method and its mitochondrial genome (mitogenome) was assembled to examine its genetic variation and phylogenetic position. The complete mitogenome of Nurudea zhengii is 15,392 bp in length, and consists of 13 protein-coding genes, 22 tRNAs, two rRNAs and one D-loop region. The gene order follows the mitogenomes of the other Rhus gall aphids, and similarly has an AT bias with the content of 83.9%. The majority strand is A-skewed and C-skewed, and shows opposite skewness for G-skewed in the minority strands. The ratios of nonsynonymous to synonymous substitution rates of protein-coding genes are lower than one except for ATP8, which indicated that ATP8 was undergoing positive selection. Phylogenetic analysis among the Rhus gall aphids based on 13 protein-coding genes and two rRNA genes showed that N. zhengii was sister to N. shiraii, and then clustered with N. yanoniella as a group with high support value. The two species, N. shiraii and N. yanoniella, share the same host plant Rhus chinensis, while the host of N. zhengii is R. hypoleuca. However, the phylogenetic relationship indicated that the taxa sharing the same host plant were not absolutely clustered as the closest taxa at least at species level.
RESUMEN
Jasminum mesnyi Hance is an important medicinal and ornamental plant. This species is native to South Central China and Vietnam and grows primarily in the subtropical biomes. In June 2022, 17 Colletotrichum strains were isolated from leaf tip blight on foliage of J. mesnyi in Nanjing, Jiangsu, China. Based on morphological characteristics and multilocus phylogenetic analyses of six genomic loci (ITS, CAL, ACT, TUB2, CHS-1, and GAPDH), a new species, namely, C. nanjingense, and a known species, namely, C. gloeosporioides s.s., were described and reported. Pathogenicity tests revealed that both species were pathogens causing leaf tip blight on J. mesnyi. The results provided necessary information for disease control and enhanced our understanding of the diversity of Colletotrichum species in China.