| 1. |
- Kattge, Jens, et al.
(författare)
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TRY plant trait database - enhanced coverage and open access
- 2020
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Ingår i: Global Change Biology. - : Wiley-Blackwell. - 1354-1013 .- 1365-2486. ; 26:1, s. 119-188
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Tidskriftsartikel (refereegranskat)abstract
- Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives.
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| 2. |
- Cavender, James C., et al.
(författare)
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New dictyostelid cellular slime molds from South Africa
- 2018
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Ingår i: Phytotaxa. - : MAGNOLIA PRESS. - 1179-3155 .- 1179-3163. ; 383:3, s. 233-251
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Tidskriftsartikel (refereegranskat)abstract
- A distributional study of the dictyostelid cellular slime molds (dictyostelids) of South Africa was carried out during 2006 as part of the Global Biodiversity of Eumycetozoans project based at the University of Arkansas and funded by the National Science Foundation Samples of soil/humus collected from 31 study sites yielded a total of 881 clones, with an average density of 210 clones/gram for all samples in which dictyostelids were detected. Eighteen different species were represented by one or more clones, and six of these could not be identified. These six species are described herein as new to science. In addition, information is provided on the ecological distribution of all of the species of dictyostelids now known to occur in South Africa.
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| 3. |
- Sheikh, Sanea, et al.
(författare)
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A New Classification of the Dictyostelids
- 2018
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Ingår i: Protist. - : Elsevier BV. - 1434-4610 .- 1618-0941. ; 169:1, s. 1-28
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Tidskriftsartikel (refereegranskat)abstract
- Traditional morphology-based taxonomy of dictyostelids is rejected by molecular phylogeny. A new classification is presented based on monophyletic entities with consistent and strong molecular phylogenetic support and that are, as far as possible, morphologically recognizable. All newly named clades are diagnosed with small subunit ribosomal RNA (18S rRNA) sequence signatures plus morphological synapomorphies where possible. The two major molecular clades are given the rank of order, as Acytosteliales ord. nov. and Dictyosteliales. The two major clades within each of these orders are recognized and given the rank of family as, respectively, Acytosteliaceae and Cavenderiaceae fam. nov. in Acytosteliales, and Dictyosteliaceae and Raperosteliaceae fam. nov. in Dictyosteliales. Twelve genera are recognized: Cavenderia gen. nov. in Cavenderiaceae, Acytostelium, Rostrostelium gen. nov. and Heterostelium gen. nov. in Acytosteliaceae, Tieghemostelium gen. nov., Hagiwaraea gen. nov., Raperostelium gen. nov. and Speleostelium gen. nov. in Raperosteliaceae, and Dictyostelium and Polysphondylium in Dictyosteliaceae. The “polycephalum” complex is treated as Coremiostelium gen. nov. (not assigned to family) and the “polycarpum” complex as Synstelium gen. nov. (not assigned to order and family). Coenonia, which may not be a dictyostelid, is treated as a genus incertae sedis. Eighty-eight new combinations are made at species and variety level, and Dictyostelium ammophilum is validated.
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| 4. |
- Cavender, James C., et al.
(författare)
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New small dictyostelids from seasonal rainforests of Central America
- 2013
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Ingår i: Mycologia. - : Informa UK Limited. - 0027-5514 .- 1557-2536. ; 105:3, s. 610-635
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Tidskriftsartikel (refereegranskat)abstract
- Ten small dictyostelids isolated from samples collected from the surface humus layer of seasonal rainforests of Belize and Guatemala were studied morphologically, and nine were found to represent distinct species, all with an average height of < 2 mm (0.5-3.5 mm). Although their fruiting bodies (sorocarps) closely resemble one another, the nine species differ in their patterns of aggregation, stream pattern, branching development, formation of microcysts, spore shape, presence or absence of spore granules and their distribution, as well as in the shapes and behavior of their sorogens and myxamoebae. These stable morphological features were sufficient to recognize nine new species of small dictyostends, one with two varieties. SSU rDNA sequences were generated for all these new isolates, and phylogenetic analyses of these sequences show these new isolates belong to Dictyostelid group 3. As a result of this and other recent studies, the concept of what constitutes a species in the dictyostelids has become much more restricted and well defined, in as much as some of the morphological and behavioral patterns now being observed were overlooked in the past. The extent, flow direction and conformation of streaming within the group varies from simple aggregation mounds with no streams to short streams, to somewhat longer streams and finally to well developed streams. Each of these is characterized by a particular set of distinguishing features.
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| 5. |
- Cavender, James C., et al.
(författare)
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New species of Polysphondylium from Madagascar
- 2016
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Ingår i: Mycologia. - : Informa UK Limited. - 0027-5514 .- 1557-2536. ; 108:1, s. 80-109
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Tidskriftsartikel (refereegranskat)abstract
- Two series of samples collected for isolation of dictyostelid cellular slime molds (dictyostelids) in Madagascar yielded a relatively large number of isolates of Polysphondylium. Most of these turned out to be species new to science that show varying degrees of clustering from unclustered to coremiform as well as an ability to migrate. Migratory ability (phototaxis) is a common feature of species assigned to Group 2 of the Polysphondylia and is common in the new species from Madagascar. Another common feature, clustering, appears to be a strategy for keeping fruiting bodies erect for a longer time in a climate that is relatively dry, whereas migratory ability may function seasonally when there is more rainfall. Thirteen species are described herein. Each of these is characterized by a particular set of distinguishing features, and collectively they expand our concept of the genus Polysphondylium.
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| 6. |
- Landolt, John C., et al.
(författare)
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Costa Rican dictyostelids, with notes on the taxonomy, phylogeny and ecology of Dictyostelium discoideum
- 2014
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Ingår i: Sydowia. - 0082-0598. ; 66:1, s. 129-142
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Tidskriftsartikel (refereegranskat)abstract
- In 1962 and then over the period of 1993-2001, samples of soil/litter for isolation of cellular slime molds (dictyostelids) were collected throughout Costa Rica. Collecting sites included examples of all major forest types found in the country and ranged in elevation from 10 to 3000 m. More than 3300 clones of dictyostelids were recovered from these samples. The clones included representatives of at least 24 described species along a number of isolates that do not conform closely to any known species and thus may be new to science. Greatest diversity was found in the montane/cloud forests, whereas the average number of clones per gram was highest in moist/wet forests. Distribution of species on a country-wide basis is compared with that of Mexico, another tropical country. In addition, phylogenetic analyses of 18S rDNA sequences were carried out on 12 different isolates of Dictyostelium discoideum, a predominantly temperate species that was recorded from both Costa Rica and Mexico.
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| 7. |
- Romeralo, Maria, et al.
(författare)
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An expanded phylogeny of social amoebas (Dictyostelia) shows increasing diversity and new morphological patterns
- 2011
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Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 11, s. 84-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Social Amoebae or Dictyostelia are eukaryotic microbes with a unique life cycle consisting of both uni- and multicellular stages. They have long fascinated molecular, developmental and evolutionary biologists, and Dictyostelium discoideum is now one of the most widely studied eukaryotic microbial models. The first molecular phylogeny of Dictyostelia included most of the species known at the time and suggested an extremely deep taxon with a molecular depth roughly equivalent to Metazoa. The group was also shown to consist of four major clades, none of which correspond to traditional genera. Potential morphological justification was identified for three of the four major groups, on the basis of which tentative names were assigned. Results: Over the past four years, the Mycetozoan Global Biodiversity Survey has identified many new isolates that appear to be new species of Dictyostelia, along with numerous isolates of previously described species. We have determined 18S ribosomal RNA gene sequences for all of these new isolates. Phylogenetic analyses of these data show at least 50 new species, and these arise from throughout the dictyostelid tree breaking up many previously isolated long branches. The resulting tree now shows eight well-supported major groups instead of the original four. The new species also expand the known morphological diversity of the previously established four major groups, violating nearly all previously suggested deep morphological patterns. Conclusions: A greatly expanded phylogeny of Dictyostelia now shows even greater morphological plasticity at deep taxonomic levels. In fact, there now seem to be no obvious deep evolutionary trends across the group. However at a finer level, patterns in morphological character evolution are beginning to emerge. These results also suggest that there is a far greater diversity of Dictyostelia yet to be discovered, including novel morphologies.
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| 8. |
- Romeralo, Maria, et al.
(författare)
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Two new species of dictyostelid cellular slime molds from Alaska
- 2010
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Ingår i: Mycologia. - : Informa UK Limited. - 0027-5514 .- 1557-2536. ; 102:3, s. 588-595
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Tidskriftsartikel (refereegranskat)abstract
- In sampling soils to survey dictyostelid cellular slime molds in Alaska we encountered two groups of isolates that have morphologies that differ from any previously described species within their group. We sequenced the nuclear small subunit ribosomal RNA gene (SSU rDNA) of selected isolates from the two groups and found sequences from both groups to be distinct from all previously described dictyostelid sequences. Phylogenetic analyses place one novel species in dictyostelid Group 2 and the other in Group 4 (Schaap et al. 2006). In this paper we formally describe as new these two species of cellular slime molds, Dictyostelium ammophilum sp. nov. and Dictyostelium borealesp. nov., based on the combination of morphological and molecular characters.
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| 9. |
- Romeralo, Maria, et al.
(författare)
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A new species of cellular slime mold from southern Portugal based on morphology, ITS and SSU sequences
- 2009
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Ingår i: Mycologia. - : Informa UK Limited. - 0027-5514 .- 1557-2536. ; 101:2, s. 269-274
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Tidskriftsartikel (refereegranskat)abstract
- Sampling soils to look for dictyostelids in southern Portugal we found an isolate that has a morphology that. differed from any previously described species of the group. We sequenced the internally transcribed spacer (ITS) and small subunit (SSU) genes of the nuclear ribosomal RNA and found that both sequences are distinct front all previously described sequences. Phylogenetic analyses place the new species in dictyostelid Group 3 (Rhizostelids) together with D. potamoides, with which it shares 65.8% identity for ITS and 96.6% for SSU. In this paper we describe a new species of cellular slime mold, Dictyostelium, ibericum, based on morphological and molecular characters. It is it small species with polar granules in its spores.
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