Showing papers on "Genus published in 2015"

Phylogenomics and systematics in Pseudomonas

Abstract: The genus Pseudomonas currently contains 144 species, making it the genus of Gram-negative bacteria that contains the largest number of species. Currently, multilocus sequence analysis (MLSA) is the preferred method for establishing the phylogeny between species and genera. Four partial gene sequences of housekeeping genes (16S rRNA, gyrB, rpoB, and rpoD) were obtained from 112 complete or draft genomes of strains related to the genus Pseudomonas that were available in databases. These genes were analyzed together with the corresponding sequences of 133 Pseudomonas type strains of validly published species to assess their correct phylogenetic assignations. We confirmed that 30% of the sequenced genomes of non-type strains were not correctly assigned at the species level in the accepted taxonomy of the genus and that 20% of the strains were not identified at the species level. Most of these strains had been isolated and classified several years ago, and their taxonomic status has not been updated by modern techniques. MLSA was also compared with indices based on the analysis of whole-genome sequences that have been proposed for species delineation, such as tetranucleotide usage patterns (TETRA), average nucleotide identity (ANIm, based on MUMmer and ANIb, based on BLAST) and genome-to-genome distance (GGDC). TETRA was useful for discriminating Pseudomonas from other genera, whereas ANIb and GGDC clearly separated strains of different species. ANIb showed the strongest correlation with MLSA. The correct species classification is a prerequisite for most diversity and evolutionary studies. This work highlights the necessity for complete genomic sequences of type strains to build a phylogenomic taxonomy and that all new genome sequences submitted to databases should be correctly assigned to species to avoid taxonomic inconsistencies.

Classification of marine Ascomycota, Basidiomycota, Blastocladiomycota and Chytridiomycota

Abstract: This paper lists the accepted names and classification of marine fungi, updating the scheme presented in 2009. The classification includes 1,112 species (in 472 genera): Ascomycota 805 (in 352 genera), Basidiomycota 21 species (in 17 genera), Chytridiomycota and related phyla 26 species (in 13 genera), Zygomycota three (in two genera), Blastocladiomycota one species (one genus), asexual morphs of filamentous fungi 43 (in 26 genera); and marine yeasts: Ascomycota 138 species (in 35 genera), Basidiomycota 75 species (in 26 genera). These fungi belong to 129 families and 65 orders. The Halosphaeriaceae remains the largest family of marine fungi with 141 species in 59 genera, while the most specious genera are Aspergillus (47 species), Penicillium (39 species) and the yeast genus Candida (64 species). The review includes details of recent higher order nomenclature changes, and accounts of new families, genera and species described over the past 5 years.

A phylogenetic classification of jumping spiders (Araneae: Salticidae)

Abstract: The classification of jumping spiders (Salticidae) is revised to bring it into accord with recent phylogenetic work. Of the 610 recognized extant and fossil genera, 588 are placed at least to subfamily, most to tribe, based on both molecular and morphological information. The new subfamilies Onomastinae, Asemoneinae, and Eupoinae, and the new tribes Lapsiini, Tisanibini, Neonini, Mopsini, and Nannenini, are described. A new unranked clade, the Simonida, is recognized. Most other family-group taxa formerly ranked as subfamilies are given new status as tribes or subtribes. The large long-recognized clade recently called the Salticoida is ranked as a subfamily, the Salticinae, with the name Salticoida reassigned to its major subgroup (the sister group to the Amycoida). Heliophaninae Petrunkevitch and Pelleninae Petrunkevitch are considered junior synonyms of Chrysillini Simon and Harmochirina Simon respectively. Spartaeinae Wanless and Euophryini Simon are preserved despite older synonyms. The genus...

Cautionary tale of using 16S rRNA gene sequence similarity values in identification of human-associated bacterial species

Abstract: Modern bacterial taxonomy is based on a polyphasic approach that combines phenotypic and genotypic characteristics, including 16S rRNA sequence similarity. However, the 95 % (for genus) and 98.7 % (for species) sequence similarity thresholds that are currently recommended to classify bacterial isolates were defined by comparison of a limited number of bacterial species, and may not apply to many genera that contain human-associated species. For each of 158 bacterial genera containing human-associated species, we computed pairwise sequence similarities between all species that have names with standing in nomenclature and then analysed the results, considering as abnormal any similarity value lower than 95 % or greater than 98.7 %. Many of the current bacterial species with validly published names do not respect the 95 and 98.7 % thresholds, with 57.1 % of species exhibiting 16S rRNA gene sequence similarity rates ≥98.7 %, and 60.1 % of genera containing species exhibiting a 16S rRNA gene sequence similarity rate <95 %. In only 17 of the 158 genera studied (10.8 %), all species respected the 95 and 98.7 % thresholds. As we need powerful and reliable taxonomical tools, and as potential new tools such as pan-genomics have not yet been fully evaluated for taxonomic purposes, we propose to use as thresholds, genus by genus, the minimum and maximum similarity values observed among species.

Rhizoglomus, a new genus of the Glomeraceae

Abstract: Rhizoglomus gen. nov. (Glomeraceae, Glomeromycetes) is proposed, typified by Glomus intraradices [≡ Rhizoglomus intraradices]. The genus encompasses species of arbuscular mycorrhizal fungi that frequently form abundant spores in soil and roots and is morphologically characterized by spores with cylindrical subtending hyphae (usually with an open pore at the base) and at least two or three (rarely up to five) distinct wall layers. Phylogenetically, the genus forms a separate clade in the Glomeraceae. In addition to R. intraradices, the genus includes R. aggregatum, R. antarcticum, R. arabicum, R. clarum, R. custos, R. fasciculatum, R. invermaium, R. irregulare, R. manihotis, R. microaggregatum, R. natalense, and R. proliferum. Some of these species were previously assigned to Rhizophagus (type: R. populinus), a pathogenic genus that does not belong in the Glomeromycota.

Fossil and Genetic Evidence for the Polyphyletic Nature of the Planktonic Foraminifera "Globigerinoides", and Description of the New Genus Trilobatus

Abstract: Planktonic foraminifera are one of the most abundant and diverse protists in the oceans. Their utility as paleo proxies requires rigorous taxonomy and comparison with living and genetically related counterparts. We merge genetic and fossil evidence of “Globigerinoides”, characterized by supplementary apertures on spiral side, in a new approach to trace their “total evidence phylogeny” since their first appearance in the latest Paleogene. Combined fossil and molecular genetic data indicate that this genus, as traditionally understood, is polyphyletic. Both datasets indicate the existence of two distinct lineages that evolved independently. One group includes “Globigerinoides” trilobus and its descendants, the extant “Globigerinoides” sacculifer, Orbulina universa and Sphaeroidinella dehiscens. The second group includes the Globigerinoides ruber clade with the extant G. conglobatus and G. elongatus and ancestors. In molecular phylogenies, the trilobus group is not the sister taxon of the ruber group. The ruber group clusters consistently together with the modern Globoturborotalita rubescens as a sister taxon. The re-analysis of the fossil record indicates that the first “Globigerinoides” in the late Oligocene are ancestral to the trilobus group, whereas the ruber group first appeared at the base of the Miocene with representatives distinct from the trilobus group. Therefore, polyphyly of the genus "Globigerinoides" as currently defined can only be avoided either by broadening the genus concept to include G. rubescens and a large number of fossil species without supplementary apertures, or if the trilobus group is assigned to a separate genus. Since the former is not feasible due to the lack of a clear diagnosis for such a broad genus, we erect a new genus Trilobatus for the trilobus group (type species Globigerina triloba Reuss) and amend Globoturborotalita and Globigerinoides to clarify morphology and wall textures of these genera. In the new concept, Trilobatus n. gen. is paraphyletic and gave rise to the Praeorbulina / Orbulina and Sphaeroidinellopsis / Sphaeroidinella lineages.

One, four or 100 genera? A new classification of the cone snails

Abstract: We present a new classification for the genus Conus sensu lato (family Conidae), based on molecular phylogenetic analyses of 329 species. This classification departs from both the traditional classification in only one genus and from a recently proposed shell- and radula-based classification scheme that separates members of this group into five families and 115 genera. Roughly 140 genus-group names are available for Recent cone snails. We propose to place all cone snails within a single family (Conidae) containing four genera—Conus, Conasprella, Profundiconus and Californiconus (with Conus alone encompassing about 85% of known species)—based on the clear separation of cone snails into four distinct and well-supported groups/ lineages in molecular phylogenetic analyses. Within Conus and Conasprella, we recognize 57 and 11 subgenera, respectively, that represent well-supported subgroupings within these genera, which we interpret as evidence of intrageneric distinctiveness. We allocate the 803 Recent species of Conidae listed as valid in the World Register of Marine Species into these four genera and 71 subgenera, with an estimate of the confidence for placement of species in these taxonomic categories based on whether molecular or radula and/or shell data were used in these determinations. Our proposed classification effectively departs from previous schemes by (1) limiting the number of accepted genera, (2) retaining the majority of species within the genus Conus and (3) assigning members of these genera to species groups/subgenera to enable the effective communication of these groups, all of which we hope will encourage acceptance of this scheme.

Cladosporium Species Recovered from Clinical Samples in the United States

Abstract: Cladosporium species are ubiquitous, saprobic, dematiaceous fungi, only infrequently associated with human and animal opportunistic infections. We have studied a large set of Cladosporium isolates recovered from clinical samples in the United States to ascertain the predominant species there in light of recent taxonomic changes in this genus and to determine whether some could possibly be rare potential pathogens. A total of 92 isolates were identified using phenotypic and molecular methods, which included sequence analysis of the internal transcribed spacer (ITS) region and a fragment of the large subunit (LSU) of the nuclear ribosomal DNA (rDNA), as well as fragments of the translation elongation factor 1 alpha (EF-1α) and actin (Act) genes. The most frequent species was Cladosporium halotolerans (14.8%), followed by C. tenuissimum (10.2%), C. subuliforme (5.7%), and C. pseudocladosporioides (4.5%). However, 39.8% of the isolates did not correspond to any known species and were deemed to comprise at least 17 new lineages for Cladosporium. The most frequent anatomic site of isolation was the respiratory tract (54.5%), followed by superficial (28.4%) and deep tissues and fluids (14.7%). Species of the two recently described cladosporiumlike genera Toxicocladosporium and Penidiella are reported for the first time from clinical samples. In vitro susceptibility testing of 92 isolates against nine antifungal drugs showed a variety of results but high activity overall for the azoles, echinocandins, and terbinafine.

Towards a natural classification and backbone tree for Lophiostomataceae, Floricolaceae, and Amorosiaceae fam. nov.

Abstract: The genera Lophiostoma, Misturatosphaeria and several other allied taxa in Lophiostomataceae are revisited. Accounts of these taxa, including their history, morphology, and family placement, based on molecular phylogeny, are provided. Type or representative specimens of Lophiostoma and Misturatosphaeria were examined and fresh specimens were obtained from Germany, Italy, Japan and Thailand. A multi-gene phylogenetic analysis of the lophiostomataceous genera Floricola, Lophiostoma, Misturatosphaeria and related taxa is provided. Sixteen genera including Lophiostoma, Lophiohelichrysum, Dimorphiopsis, Platystomum and Vaginatispora, plus eleven newly introduced genera Biappendiculispora, Alpestrisphaeria, Capulatispora, Coelodictyosporium, Guttulispora, Lophiopoacea, Neotrematosphaeria, Paucispora, Pseudolophiostoma, Pseudoplatystomum and Sigarispora are accepted in Lophiostomataceae based on morphology and phylogeny. Lophiostoma caulium, Lophiostoma arundinis and Lophiostoma caudatum are accommodated in Sigarispora. Lophiostoma winteri and Lophiostoma fuckelii are placed in the genera Lophiopoacea and Vaginatispora respectively. Three Curreya species and Misturatosphaeria claviformis are transferred to a new genus, Neocurreya. All other Misturatosphaeria species except Misturatosphaeria aurantiinotata and M. uniseptata are separated in the new genera Asymmetrispora, Aurantiascoma, Magnibotryascoma, Pseudoaurantiascoma and Pseudomisturatosphaeria based on their morphological and phylogenetic affinities. Another new genus, Ramusculicola is introduced for a new collection from Thailand. These seven new genera are accommodated in a new family Floricolaceae, together with Floricola and Misturatosphaeria. Several massarina-like species clustered as a sister clade to Amorosia littoralis and are accommodated in a new genus Angustimassarina. A new family Amorosiaceae is proposed to accommodate the genera Amorosia and Angustimassarina. The putatively named species Decaisnella formosa and Thyridaria macrostomoides form a separate clade together with a new genus Lignosphaeria which is placed in Dothideomycetes, genera incertae sedis.

Phylogeny of Sarocladium (Hypocreales).

Abstract: The circumscription of the genus Acremonium (Hypocreales) was recently reviewed on the basis of a DNA phylogenetic study. Several species were subsequently transferred to Sarocladium, but the relationships between both genera remained unresolved. Based on multilocus phylogenetic inferences combined with phenotypic data, we have revised the species concepts within Sarocladium and some genetically related species of Acremonium. As a result of these studies, six species are described as new, viz. S. bifurcatum, S. gamsii, S. hominis, S. pseudostrictum, S. subulatum and S. summerbellii. In addition, the new combinations S. implicatum and S. terricola are proposed for A. implicatum and A. terricola, respectively. Sarocladium attenuatum is confirmed as synonym of the type species of the genus, S. oryzae. An epitype and neotype are also introduced for S. oryzae and S. implicatum, respectively. Although Sarocladium species have traditionally been considered as important phytopathogens, the genus also contains opportunistic human pathogens. This study extends the spectrum of clinical species that could be diagnosed as causal agents of human infections.

Leaf hydraulic conductance is coordinated with leaf morpho-anatomical traits and nitrogen status in the genus Oryza

Abstract: Leaf hydraulic conductance (Kleaf) is a major determinant of photosynthetic rate in plants. Previous work has assessed the relationships between leaf morpho-anatomical traits and Kleaf with woody species, but there has been very little focus on cereal crops. The genus Oryza, which includes rice (Oryza sativa) and wild species (such as O. rufipogon cv. Griff), is ideal material for identifying leaf features associated with Kleaf and gas exchange. Leaf morpho-anatomical traits, Kleaf, leaf N content per leaf area, and CO2 diffusion efficiency were investigated in 11 Oryza cultivars. K leaf was positively correlated with leaf thickness and related traits, and therefore positively correlated with leaf mass per area and leaf N content per leaf area, and negatively with inter-veinal distance. Kleaf was also positively correlated with leaf area and its related traits, and therefore negatively correlated with the proportion of minor vein length per area. In addition, coordination between Kleaf and CO2 diffusion conductance in leaves was observed. We conclude that leaf morpho-anatomical traits and N content per leaf area strongly influence K leaf. Our results suggest that more detailed anatomical and structural studies are needed to elucidate the impacts of leaf feature traits on Kleaf and gas exchange in grasses.

Fukuyoa paulensis gen. et sp. nov., a New Genus for the Globular Species of the Dinoflagellate Gambierdiscus (Dinophyceae)

Abstract: The marine epiphytic dinoflagellate Gambierdiscus is a toxicologically important genus responsible for ciguatera fish poisoning, the principal cause of non-bacterial illness associated with fish consumption. The genus currently contains species exhibiting either globular or anterior-posteriorly compressed morphologies with marked differences in cell shape and plate arrangement. Here we report a third globular, epiphytic and tychoplanktonic species from the coasts of Ubatuba, Brazil. The new species can be distinguished from G. yasumotoi and G. ruetzleri by its broader first apical plate that occupies a larger portion of the epitheca. Accordingly, phylogenetic trees from small subunit (SSU) and large subunit (LSU) ribosomal DNA sequences also showed strongly supported separation of the new species from the G. yasumotoi / G. ruetzleri group albeit with short distance. The molecular phylogenies, which included new sequences of the planktonic species Goniodoma polyedricum, further indicated that the globular species of Gambierdiscus formed a tight clade, clearly separated (with strong bootstrap support) from the clade of lenticular species including the type for Gambierdiscus. The morphological and molecular data in concert support the split of Gambierdiscus sensu lato into two genera. Gambierdiscus sensu stricto should be reserved for the species with lenticular shapes, highly compressed anterioposteriorly, with short-shank fishhook apical pore plate, large 2' plate, low and ascending cingular displacement, and pouch-like sulcal morphology. The new genus name Fukuyoa gen. nov. should be applied to the globular species, slightly laterally compressed, with long-shank fishhook apical pore plate, large 1' plate, greater and descending cingular displacement, and not pouch-like vertically-oriented sulcal morphology. Fukuyoa contains the new species Fukuyoa paulensis gen. et sp. nov., and F. yasumotoi comb. nov. and F. ruetzleri comb. nov.

Multi-gene phylogenetic analyses of New Zealand coralline algae: Corallinapetra Novaezelandiae gen. et sp. nov. and recognition of the Hapalidiales ord. nov.

Abstract: Coralline red algae from the New Zealand region were investigated in a study focused on documenting regional diversity. We present a multi-gene analysis using sequence data obtained for four genes (nSSU, psaA, psbA, rbcL) from 68 samples. The study revealed cryptic diversity at both genus and species levels, confirming and providing further evidence of problems with current taxonomic concepts in the Corallinophycidae. In addition, a new genus Corallinapetra novaezelandiae gen. et sp. nov. is erected for material from northern New Zealand. Corallinapetra is excluded from all currently recognized families and orders within the Corallinophycidae and thus represents a previously unrecognized lineage within this subclass. We discuss rank in the Corallinophycidae and propose the order Hapalidiales.

Anthostomella is polyphyletic comprising several genera in Xylariaceae

Abstract: Anthostomella has long been regarded as a large, but polyphyletic genus in the family Xylariaceae, but species in this group generally lack phylogenetic data. In this study, 14 anthostomella-like taxa collected from Italy, were studied using both morphology and molecular data. Single ascospore isolates were obtained and the asexual morphs of five taxa established. The phylogenetic relationships of the xylariaceous taxa were inferred using combined ITS, RPB2, β tubulin and LSU gene regions. We introduce new sequence data for 24 with included the 14 new anthostomella-like taxa. The subfamilies Hypoxyloideae and Xylarioideae within Xylariaceae were recognized as the two major clades with high bootstrap support. Within the two clades 21 subclades were resolved and the anthostomella-like taxa clustered in five of these subclades indicating that the genus is polyphyletic. Anthostomella sensu stricto comprised A. forlicesenica, A. formosa, A. helicofissa, A. rubicola and A. obesa. The A. formosa and A. rubicola collections morphologically closely resemble the type specimens and therefore we designate reference specimens. Three new species Anthostomella helicofissa, A. forlicesenica and A. obesa are also introduced. Four distinct lineages of anthostomella-like taxa correspondent to four new genera, Anthocanalis, Brunneiperidium, Lunatiannulus and Pyriformiascoma, which are also introduced, while one clustered in Astrocystis and is introduced as a new species. Keys to the new anthostomella-like genera and species examined in this study are provided.

Genetics, Morphology, Advertisement Calls, and Historical Records Distinguish Six New Polyploid Species of African Clawed Frog (Xenopus, Pipidae) from West and Central Africa

Abstract: African clawed frogs, genus Xenopus, are extraordinary among vertebrates in the diversity of their polyploid species and the high number of independent polyploidization events that occurred during their diversification. Here we update current understanding of the evolutionary history of this group and describe six new species from west and central sub-Saharan Africa, including four tetraploids and two dodecaploids. We provide information on molecular variation, morphology, karyotypes, vocalizations, and estimated geographic ranges, which support the distinctiveness of these new species. We resurrect Xenopus calcaratus from synonymy of Xenopus tropicalis and refer populations from Bioko Island and coastal Cameroon (near Mt. Cameroon) to this species. To facilitate comparisons to the new species, we also provide comments on the type specimens, morphology, and distributions of X. epitropicalis, X. tropicalis, and X. fraseri. This includes significantly restricted application of the names X. fraseri and X. epitropicalis, the first of which we argue is known definitively only from type specimens and possibly one other specimen. Inferring the evolutionary histories of these new species allows refinement of species groups within Xenopus and leads to our recognition of two subgenera (Xenopus and Silurana) and three species groups within the subgenus Xenopus (amieti, laevis, and muelleri species groups).

Pantanalinema gen. nov. and Alkalinema gen. nov.: novel pseudanabaenacean genera (Cyanobacteria) isolated from saline-alkaline lakes.

Abstract: The genus Leptolyngbya Anagnostidis & Komarek (1988) was described from a set of strains identified as ‘LPP-group B’. The morphology within this group is not particularly informative and underestimates the group’s genetic diversity. In the present study, two new pseudanabaenacean genera related to Leptolyngbya morphotypes, Pantanalinema gen. nov. and Alkalinema gen. nov., are described under the provisions of the International Code of Nomenclature for Algae, Fungi and Plants, based on a polyphasic approach. Pantanalinema gen. nov. (type species Pantanalinema rosaneae sp. nov.) has sheaths and trichomes with slight gliding motility, which distinguish this genus from Alkalinema gen. nov. (type species Alkalinema pantanalense sp. nov.), which possesses trichomes arranged in an ornate (interwoven) pattern. 16S rRNA gene sequences of strains of Pantanalinema and Alkalinema exhibited low identity to each other (≤91.6 %) and to other sequences from known pseudanabaenacean genera (≤94.3 and 93.7 %, respectively). In a phylogenetic reconstruction, six sequences from strains of Pantanalinema and four from strains of Alkalinema formed two separate and robust clades (99 % bootstrap value), with the genera Oculatella and Phormidesmis, respectively, as the closest related groups. 16S–23S rRNA intergenic spacer sequences and secondary structures of strains of Pantanalinema and Alkalinema did not correspond to any previous descriptions. The strains of Pantanalinema and Alkalinema were able to survive and produce biomass at a range of pH (pH 4–11) and were also able to alter the culture medium to pH values ranging from pH 8.4 to 9.9. These data indicate that cyanobacterial communities in underexplored environments, such as the Pantanal wetlands, are promising sources of novel taxa.

A taxonomic and phylogenetic re-appraisal of the genus Curvularia ( Pleosporaceae ): human and plant pathogens

Abstract: Curvularia is an important genus whose species are widely distributed phytopathogens as well as opportunistic pathogens on human and animals. The purpose of this study is to re-evaluate the phylogenetic relationships of the species in the genus Curvularia using ITS (nuclear ribosomal internal transcribed spacer), GPDH (glyceraldehyde-3-phosphate dehydrogenase) and TEF (translation elongation factor) gene regions and to provide modern descriptions and illustrations of Curvularia australis, Curvularia buchloes, C. cymbopogonis, C. hawaiiensis, C. neoindica, C. neergaardii, C. nicotiae, C. nodulosa, C. ryleyi, and C. subpapendorfii which lack recent descriptions with details of host and distribution. A multi-gene phylogenetic tree based on ITS, GPDH and TEF gene regions is used to define species of a fresh collections obtained from various hosts and geographic locations in the world. Both human and plant associated species of Curvularia are included in the phylogenetic analysis. Some species that have previously been described from humans are herein reported from plant material as pathogens or saprobes and vice versa. Novel host associations are reported for C. asianensis, C. borreriae, C. hominis, C. muehlenbeckiae, C. trifolii and C. verruculosa.

A revision of Spondias L. (Anacardiaceae) in the Neotropics

Abstract: As part of an ongoing study of Anacardiaceae subfamily Spondioideae, the ten native and one introduced species of Spondias in the Neotropics are revised. The genus is circumscribed. Three new species, Spondiasadmirabilis, Spondiasexpeditionaria, and Spondiasglobosa, are described and illustrated; a key to the taxa found in the Neotropics and distribution maps are provided. The Paleotropical species and allied genera are reviewed. Diagnostic character sets include leaf architecture, habit, flower morphology, and gross fruit morphology. Notes on the ecology and economic botany of the species are provided.

Coalescent-based species delimitation approach uncovers high cryptic diversity in the cosmopolitan lichen-forming fungal genus Protoparmelia (Lecanorales, Ascomycota).

Abstract: Species recognition in lichen-forming fungi has been a challenge because of unsettled species concepts, few taxonomically relevant traits, and limitations of traditionally used morphological and chemical characters for identifying closely related species. Here we analyze species diversity in the cosmopolitan genus Protoparmelia s.l. The ~25 described species in this group occur across diverse habitats from the boreal -arctic/alpine to the tropics, but their relationship to each other remains unexplored. In this study, we inferred the phylogeny of 18 species currently assigned to this genus based on 160 specimens and six markers: mtSSU, nuLSU, ITS, RPB1, MCM7, and TSR1. We assessed the circumscription of species-level lineages in Protoparmelia s. str. using two coalescent-based species delimitation methods – BP&P and spedeSTEM. Our results suggest the presence of a tropical and an extra-tropical lineage, and eleven previously unrecognized distinct species-level lineages in Protoparmelia s. str. Several cryptic lineages were discovered as compared to phenotype-based species delimitation. Many of the putative species are supported by geographic evidence.

Halotia gen. nov., a phylogenetically and physiologically coherent cyanobacterial genus isolated from marine coastal environments.

Abstract: Nostoc is a common and well-studied genus of cyanobacteria and, according to molecular phylogeny, is a polyphyletic group. Therefore, revisions of this genus are urged in an attempt to clarify its taxonomy. Novel strains isolated from underexplored environments and assigned morphologically to the genus Nostoc are not genetically related to the ‘true Nostoc’ group. In this study, four strains isolated from biofilms collected in Antarctica and five strains originated from Brazilian mangroves were evaluated. Despite their morphological similarities to other morphotypes of Nostoc , these nine strains differed from other morphotypes in ecological, physiological and genetic aspects. Based on the phylogeny of the 16S rRNA gene, the Antarctic sequences were grouped together with the sequences of the Brazilian mangrove isolates and Nostoc sp. Mollenhauer 1 : 1-067 in a well-supported cluster (74 % bootstrap value, maximum-likelihood). This novel cluster was separated phylogenetically from the ‘true Nostoc’ clade and from the clades of the morphologically similar genera Mojavia and Desmonostoc. The 16S rRNA gene sequences generated in this study exhibited 96 % similarity to sequences from the nostocacean genera mentioned above. Physiologically, these nine strains showed the capacity to grow in a salinity range of 1–10 % NaCl, indicating their tolerance of saline conditions. These results provide support for the description of a new genus, named Halotia gen. nov., which is related morphologically to the genera Nostoc , Mojavia and Desmonostoc. Within this new genus, three novel species were recognized and described based on morphology and internal transcribed spacer secondary structures: Halotia branconii sp. nov., Halotia longispora sp. nov. and Halotia wernerae sp. nov., under the provisions of the International Code of Nomenclature for Algae, Fungi and Plants.

Patterns of taxonomic diversity among terrestrial isopods.

Abstract: The publication of the world catalog of terrestrial isopods some ten years ago by Schmalfuss has facilitated research on isopod diversity patterns at a global scale. Furthermore, even though we still lack a comprehensive and robust phylogeny of Oniscidea, we do have some useful approaches to phylogenetic relationships among major clades which can offer additional insights into isopod evolutionary dynamics. Taxonomic diversity is one of many approaches to biodiversity and, despite its sensitiveness to biases in taxonomic practice, has proved useful in exploring diversification dynamics of various taxa. In the present work, we attempt an analysis of taxonomic diversity patterns among Oniscidea based on an updated world list of species containing 3,710 species belonging to 527 genera and 37 families (data till April 2014). The analysis explores species diversity at the genus and family level, as well as the relationships between species per genera, species per families, and genera per families. In addition, we consider the structure of isopod taxonomic system under the fractal perspective that has been proposed as a measure of a taxon's diversification. Finally, we check whether there is any phylogenetic signal behind taxonomic diversity patterns. The results can be useful in a more detailed elaboration of Oniscidea systematics.

Species tree estimation of diploid Helianthus (Asteraceae) using target enrichment

Abstract: • Premise of the study: The sunflower genus Helianthus has long been recognized as economically significant, containing species of agricultural and horticultural importance. Additionally, this genus displays a large range of phenotypic and genetic variation, making Helianthus a useful system for studying evolutionary and ecological processes. Here we present the most robust Helianthus phylogeny to date, laying the foundation for future studies of this genus. • Methods: We used a target enrichment approach across 37 diploid Helianthus species/subspecies with a total of 103 accessions. This technique garnered 170 genes used for both coalescent and concatenation analyses. The resulting phylogeny was additionally used to examine the evolution of life history and growth form across the genus. • Key results: Coalescent and concatenation approaches were largely congruent, resolving a large annual clade and two large perennial clades. However, several relationships deeper within the phylogeny were more weakly supported and incongruent among analyses including the placement of H. agrestis , H. cusickii , H. gracilentus , H. mollis , and H. occidentalis . • Conclusions: The current phylogeny supports three major clades including a large annual clade, a southeastern perennial clade, and another clade of primarily large-statured perennials. Relationships among taxa are more consistent with early phylogenies of the genus using morphological and crossing data than recent efforts using single genes, which highlight the difficulties of phylogenetic estimation in genera known for reticulate evolution. Additionally, conflict and low support at the base of the perennial clades may suggest a rapid radiation and/or ancient introgression within the genus.

Reinstatement of Tetradesmus G. M. Smith (Sphaeropleales, Chlorophyta)

Abstract: Earlier and more recent history of the relationship between the desmid genera Acutodesmus and Tetradesmus (Sphaeropleales, Chlorophyta) is discussed. It is pointed out that current taxonomic treatments are using the name Acutodesmus (Hegewald) Tsarenko, which dates as a genus only from 2001. Taxonomic treatments are now including in Acutodesmus A. wisconsinensis, which is the type species of the earlier generic name Tetradesmus of G. M. Smith (1913). Because of the priority of Tetradesmus, ten taxa are transferred to that genus. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Phylogenetic Relationships of American Willows (Salix L., Salicaceae)

Abstract: Salix L. is the largest genus in the family Salicaceae (450 species). Several classifications have been published, but taxonomic subdivision has been under continuous revision. Our goal is to establish the phylogenetic structure of the genus using molecular data on all American willows, using three DNA markers. This complete phylogeny of American willows allows us to propose a biogeographic framework for the evolution of the genus. Material was obtained for the 122 native and introduced willow species of America. Sequences were obtained from the ITS (ribosomal nuclear DNA) and two plastid regions, matK and rbcL. Phylogenetic analyses (parsimony, maximum likelihood, Bayesian inference) were performed on the data. Geographic distribution was mapped onto the tree. The species tree provides strong support for a division of the genus into two subgenera, Salix and Vetrix. Subgenus Salix comprises temperate species from the Americas and Asia, and their disjunction may result from Tertiary events. Subgenus Vetrix is composed of boreo-arctic species of the Northern Hemisphere and their radiation may coincide with the Quaternary glaciations. Sixteen species have ambiguous positions; genetic diversity is lower in subg. Vetrix. A molecular phylogeny of all species of American willows has been inferred. It needs to be tested and further resolved using other molecular data. Nonetheless, the genus clearly has two clades that have distinct biogeographic patterns.