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One Genus (one + genus)

Distribution by Scientific Domains

Life Sciences	66%

Selected Abstracts

Notes on the family Brassicaceae in China

JOURNAL OF SYSTEMATICS EVOLUTION, Issue 3 2009
Dmitry A GERMAN
Abstract A critical revision of the collections of Brassicaceae in some Chinese (PE, XJA, XJBI, XJFA, XJNM, XJU) and foreign (LE, P) herbaria is made. One genus, Neurotropis (DC.) F. K. Mey., and 11 species, Alyssum szarabiacum Nyár., Barbarea stricta Andrz., Erysimum czernjajevii N. Busch, Erysimum kotuchovii D. German, Erysimum mongolicum D. German, Lepidium karelinianum Al-Shehbaz, Matthiola superba Conti, Neurotropis platycarpa (Fisch. & Mey.) F. K. Mey., Ptilotrichum dahuricum Peschkova, Sisymbrium subspinescens Bunge, and Smelowskia micrantha (Botsch. & Vved.) Al-Shehbaz & S. I. Warwick, are reported from China for the first time. Six species, Aphragmus involucratus (Bunge) O. E. Schulz, Dontostemon perennis C. A. Mey., Goldbachia torulosa DC., Lepidium amplexicaule Willd., Neotorularia brevipes (Kar. & Kir.) Hedge & J. Léonard, and Parrya stenocarpa Kar. & Kir., are confirmed to occurr in China. Five species, Dontostemon integrifolius (L.) C. A. Mey., Draba zangbeiensis L. L. Lou, Lepidium alashanicum H. L. Yang, Sinapis arvensis L., and Strigosella brevipes (Bunge) Botsch., are reported as novelties for some provinces in China, and Strigosella hispida (Litv.) Botsch. occurs in Xinjiang, China. However, the occurrence of one genus, Pseudoarabidopsis Al-Shehbaz, O'Kane & Price, and four species, Draba huetii Boiss., Eutrema halophilum (C. A. Mey.) Al-Shehbaz & S. I. Warwick, Galitzkya spathulata (Steph. ex Willd.) V. Bocz., and Pseudoarabidopsis toxophylla (Bieb.) Al-Shehbaz, O'Kane & Price, could not be confirmed in China. The occurrence of six species, Aphragmus bouffordii Al-Shehbaz, Barbarea orthoceras Ledeb., Lepidium latifolium L., Ptilotrichum canescens (DC.) C. A. Mey., Strigosella hispida (Litv.) Botsch., and Strigosella scorpioides (Bunge) Botsch., is not confirmed in certain provinces of China. All names follow the latest taxonomic treatment for relevant groups; detailed morphological descriptions of the newly recorded taxa are provided; and distinguishing characters from related species already known in China are discussed. Other comments are provided where needed. [source]

Bacterial diversity in aphthous ulcers

MOLECULAR ORAL MICROBIOLOGY, Issue 4 2007
L. Marchini
Introduction:, Recurrent aphthous ulcers are common lesions of the oral mucosa of which the etiology is unknown. This study aimed to estimate the bacterial diversity in the lesions and in control mucosa in pooled samples using a culture-independent molecular approach. Methods:, Samples were collected from ten healthy individuals and ten individuals with a clinical history of recurrent aphthous ulcers. After DNA extraction, the 16S ribosomal RNA bacterial gene was amplified by polymerase chain reaction with universal primers; amplicons were cloned, sequenced and matched to the GenBank database. Results:, A total of 535 clones were analyzed, defining 95 bacterial species. We identified 62 putative novel phylotypes. In recurrent aphthous ulcer lesions 57 phylotypes were detected, of which 11 were known species. Control samples had 38 phylotypes, five of which were already known. Only three species or phylotypes were abundant and common to both groups (Gemella haemolysans, Streptococcus mitis strain 209 and Streptococcus pneumoniae R6). One genus was found only in recurrent aphthous ulcer samples (Prevotella) corresponding to 16% of all lesion-derived clones. Conclusion:, The microbiota found in recurrent aphthous ulcers and in the control groups diverged markedly and the rich variety of genera found can provide a new starting point for individual qualitative and quantitative analyses of bacteria associated with this oral condition. [source]

Conifers as invasive aliens: a global survey and predictive framework

DIVERSITY AND DISTRIBUTIONS, Issue 5-6 2004
David M. Richardson
ABSTRACT We summarize information on naturalized and invasive conifers (class Pinopsida) worldwide (data from 40 countries, some with remote states/territories), and contrast these findings with patterns for other gymnosperms (classes Cycadopsida, Gnetopsida and Ginkgoopsida) and for woody angiosperms. Eighty conifer taxa (79 species and one hybrid; 13% of species) are known to be naturalized, and 36 species (6%) are ,invasive'. This categorization is based on objective and conservative criteria relating to consistency of reproduction, distance of spread from founders, and degree of reliance on propagules from the founder population for persistence in areas well outside the natural range of species. Twenty-eight of the known invasive conifers belong to one family (Pinaceae) and 21 of these are in one genus (Pinus). The Cupressaceae (including Taxodiaceae) has six known invasive species (4%) in four genera, but the other four conifer families have none. There are also no known invasive species in classes Cycadopsida, Gnetopsida or Ginkgoopsida. No angiosperm family comprising predominantly trees and shrubs has proportionally as many invasive species as the Pinaceae. Besides the marked taxonomic bias in favour of Pinaceae, and Pinus in particular, invasiveness in conifers is associated with a syndrome of life-history traits: small seed mass (< 50 mg), short juvenile period (< 10 year), and short intervals between large seed crops. Cryptomeria japonica, Larix decidua, Picea sitchensis, Pinus contorta, Pinus strobus, and Pseudotsuga menziesii exemplify this syndrome. Many rare and endangered conifer species exhibit opposite characters. These results are consistent with earlier predictions made using a discriminant function derived from attributes of invasive and noninvasive Pinus species. Informative exceptions are species with small seeds (< 4 mg, e.g. Chamaecyparis spp., Pinus banksiana, Tsuga spp. , mostly limited to wet/mineral substrates) or otherwise ,non-invasive' characters (e.g. large seeds, fleshy fruits, e.g. Araucaria araucana, Pinus pinea, Taxus baccata that are dependent on vertebrates for seed dispersal). Most conifers do not require coevolved mutualists for pollination and seed dispersal. Also, many species can persist in small populations but have the genetic and reproductive capacity to colonize and increase population size rapidly. The underlying mechanisms mediating conifer invasions are thus easier to discern than is the case for most angiosperms. Further information is needed to determine the extent to which propagule pressure (widespread dissemination, abundant plantings, long history of cultivation) can compensate for low ,inherent invasiveness'. [source]

Evolution of a complex coevolved trait: active pollination in a genus of fig wasps

JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 2 2004
J. M. Cook
Abstract Only three insect lineages have evolved complex active pollination behaviour and only fig wasps (Agaonidae) have also reverted from active to passive pollination. Previously, it was assumed that there was a single origin of active pollination in fig wasps, followed by one independent loss in each of five genera. We show here that there have been three to six changes in pollination behaviour within just one genus (Pleistodontes). The results suggest multiple gains of active pollination in fig wasps, but are sensitive to assumptions about the relative costs of gaining and losing this complex behaviour. In addition, previous comparative studies at higher taxonomic levels have reported correlated evolution between active pollination in wasps and low anther/ovule ratios in figs. We report that changes in pollination behaviour between congeneric species correlate perfectly with changes in anther/ovule ratios in the host figs, showing no phylogenetic inertia in coadaptation at the species level. [source]

Notes on the family Brassicaceae in China

THE AERODYNAMICS OF THE BRITISH LATE TRIASSIC KUEHNEOSAURIDAE

PALAEONTOLOGY, Issue 4 2008
KOEN STEIN
Abstract:, The Kuehneosauridae (Late Triassic, Britain, USA) had remarkable adaptations, most notably their elongate mid-dorsal ribs that were presumably covered with a skin membrane in life. These lateral ,wings' have always been linked with some form of gliding adaptation, but quantitative studies have been limited. Here, we provide a thorough aerodynamic analysis of both genera of British kuehneosaurids based on theory and on experiments with life-sized models in a wind tunnel. Of the two genera, Kuehneosuchus, with elongate ,wings', was a glider, and Kuehneosaurus, with much shorter ,wings', was a parachutist. Kuehneosuchus most probably had highly cambered wings and no additional skin membranes on hands or feet, nor did it have a cruropatagium. Lappets on the hyoid apparatus, as seen in Draco, were probably present to enhance pitch control. Kuehneosuchus was capable of gliding at angles (,) between 13 and 16 degrees, at speeds between 7 and 9 m/s, and was probably very manoeuvrable when airborne. Kuehneosaurus was capable of parachuting (, > 45 degrees) at speeds between 10 and 12 m/s. It is unclear whether the British kuehneosaurid material represents two genera, as assumed here, two species of one genus, or sexual dimorphs of a single species, where the gliding Kuehneosuchus was the male, which used its gliding and perhaps highly coloured ,wings' to display to the parachuting Kuehneosaurus. [source]