826 resultados para Taxonomic Key
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PREMISE OF THE STUDY: Numerous long-term studies in seasonal habitats have tracked interannual variation in first flowering date (FFD) in relation to climate, documenting the effect of warming on the FFD of many species. Despite these efforts, long-term phenological observations are still lacking for many species. If we could forecast responses based on taxonomic affinity, however, then we could leverage existing data to predict the climate-related phenological shifts of many taxa not yet studied. METHODS: We examined phenological time series of 1226 species occurrences (1031 unique species in 119 families) across seven sites in North America and England to determine whether family membership (or family mean FFD) predicts the sensitivity of FFD to standardized interannual changes in temperature and precipitation during seasonal periods before flowering and whether families differ significantly in the direction of their phenological shifts. KEY RESULTS: Patterns observed among species within and across sites are mirrored among family means across sites; early-flowering families advance their FFD in response to warming more than late-flowering families. By contrast, we found no consistent relationships among taxa between mean FFD and sensitivity to precipitation as measured here. CONCLUSIONS: Family membership can be used to identify taxa of high and low sensitivity to temperature within the seasonal, temperate zone plant communities analyzed here. The high sensitivity of early-flowering families (and the absence of early-flowering families not sensitive to temperature) may reflect plasticity in flowering time, which may be adaptive in environments where early-season conditions are highly variable among years.
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Recent studies assessing the role of biological diversity for ecosystem functioning indicate that the diversity of functional traits and the evolutionary history of species in a community, not the number of taxonomic units, ultimately drives the biodiversity-ecosystem-function relationship. Here, we simultaneously assessed the importance of plant functional trait and phylogenetic diversity as predictors of major trophic groups of soil biota (abundance and diversity), six years from the onset of a grassland biodiversity experiment. Plant functional and phylogenetic diversity were generally better predictors of soil biota than the traditionally used species or functional group richness. Functional diversity was a reliable predictor for most biota, with the exception of soil microorganisms, which were better predicted by phylogenetic diversity. These results provide empirical support for the idea that the diversity of plant functional traits and the diversity of evolutionary lineages in a community are important for maintaining higher abundances and diversity of soil communities.
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Capsula and seed morphology of W. European species of Euphorbia aggr. flavicoma has been studied. A total of 1500 seeds coming from 13 taxa have been investigated under light microscope, scanning electron microscope and binocular stereoscope. Data were processed by multivariate analysis and the corresponding dendrogram is presented. At de end of the paper, a key is presented allowing to the separation of taxa down to the species level.
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Background and aims Unilateral incompatibility (UI) occurs when pollinations between species are successful in one direction but not in the other. Self-incompatible (SI) species frequently show UI with genetically related, self-compatible (SC) species, as pollen of SI species is compatible on the SC pistil, but not vice versa. Many examples of unilateral incompatibility, and all those which have been studied most intensively, are found in the Solanaceae, particularly Lycopersicon, Solanum, Nicotiana and Petunia. The genus Capsicum is evolutionarily somewhat distant from Lycopersicon and Solanum and even further removed from Nicotiana and Petunia. Unilateral incompatibility has also been reported in Capsicum; however, this is the first comprehensive study of crosses between all readily available species in the genus. Methods All readily available (wild and domesticated) species in the genus are used as plant material, including the three genera from the Capsicum pubescens complex plus eight other species. Pollinations were made on pot-grown plants in a glasshouse. The number of pistils pollinated per cross varied (from five to 40 pistils per plant), depending on the numbers of flowers available. Pistils were collected 24 h after pollination and fixed for 3-24 h. After staining, pistils were mounted in a drop of stain, squashed gently under a cover slip and examined microscopically under ultra-violet light for pollen tube growth. Key results Unilateral incompatibility is confirmed in the C. pubescens complex. Its direction conforms to that predominant in the Solanaceae and other families, i.e. pistils of self-incompatible species, or self-compatible taxa closely related to self-incompatible species, inhibit pollen tubes of self-compatible species. Conclusions Unilateral incompatibility in Capsicum does not seem to have arisen to prevent introgression of self-compatibility into self-incompatible taxa, but as a by-product of divergence of the C. pubescens complex from the remainder of the genus. (C) 2004 Annals of Botany Company.
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Myosotic cameroonensis Cheek & R Becker (Boraginacene) is described from Cameroon. Its conservation status and taxonomic affinities are assessed and an updated key to the Tropical African species of the genus is presented.
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Tribe Rhipsalideae is composed of unusual epiphytic or lithophytic cacti that inhabit humid tropical and subtropical forests. Members of this tribe present a reduced vegetative body, a specialized adventitious root system, usually spineless areoles and flowers and fruits reduced in size. Despite the debate surrounding the classification of Rhipsalideae, no studies have ever attempted to reconstruct phylogenetic relationships among its members or to test the monophyly of its genera using DNA sequence data; all classifications formerly proposed for this tribe have only employed morphological data. In this study, we reconstruct the phylogeny of Rhipsalideae using plastid (trnQ-rps16, rpl32-trnL, psbA-trnH) and nuclear (ITS) markers to evaluate the classifications previously proposed for the group. We also examine morphological features traditionally used to delimit genera within Rhipsalideae in light of the resulting phylogenetic trees. In total new sequences for 35 species of Rhipsalideae were produced (out of 55: 63%). The molecular phylogeny obtained comprises four main clades supporting the recognition of genera Lepismium, Rhipsalis, Hatiora and Schlumbergera. The evidence gathered indicate that a broader genus Schlumbergera, including Hatiora subg. Rhipsalidopsis, should be recognized. Consistent morphological characters rather than homoplastic features are used in order to establish a more coherent and practical classification for the group. Nomenclatural changes and a key for the identification of the genera currently included in Rhipsalideae are provided. (C) 2011 Elsevier Inc. All rights reserved.
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Borgmeiermyia Townsend, 1935 is a small Neotropical genus of Tachinidae (Diptera) with four described species. Brief descriptions are given to the previously unknown females of B. brasiliana Townsend, 1935 and B. paraguayana Sehnal, 1998, and the male of B. peruana Arnaud, 1963. An identification key to the four known species is given, as well as comments on characters with intraspecific variation. Change of depository of the holotype of B. brasiliana from one institution to another is discussed and its current location is given. Also, the first host is recorded for the genus with the occurrence of B. paraguayana para-sitizing Phylloptera aff. ovalifolia Burmeister, 1839 (Orthoptera: Tettigoniidae: Phaneropterinae).
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The status of the Lauxaniidae genus Rhabdolauxania Hendel, 1925 is reevaluated and is synonymized under Neogriphoneura Malloch, 1924. Three new combinations, N. immaculata (Hendel, 1933), comb. nov., N. laevifrons (Hendel, 1925), comb. nov., and N. schnusei (Hendel, 1925), comb. nov. are proposed. Two lectotypes are designated. Three new species of Neogriphoneura are described: N. bispoi sp. nov., from Santa Catarina, Brazil, N. pacata sp. nov., from La Paz, Bolivia, and N. corrugata sp. nov. from British Virgin Islands. Illustrations of the head, wing, male and female terminalia are provided for the new species. This raises the number of species in the genus from the present five to eleven. A key is provided for the species of the genus.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The understanding of the subfamily Landrevinae has been modified by different authors since its creation. In the neotropics three genera are known to the present: Odontogryllus Saussure, 1877 (one from México, the others amazonian), Brasilodontus de Mello, 1992 with two species (from Brazilian Atlantic Forest), e Valchica de Mello, 1992 with one species (from Costa Rica). De Mello (1992) erroneously created the tribe Odontogryllini for this cluster of neotropical genera, here suppressed. In the present paper we revise and add new species to Brasilodontus and describe two monotypic genera, Xulavuna n. gen. and Yarrubura, n. gen. An identification key to the genera of neotropical Landrevinae is presented as well as one for the species of Brasilodontus. The male fore wings of Xulavuna adenoptera n. sp. is remarkable regarding its shape and its glandular condition
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Nycterilampus Montrouzier, 1860, from Oceania, is removed from junior synonymy with Tetrigus Candeze, 1857, and is redescribed and revalidated. The genus includes two species, N. lifuanus Montrouzier, 1860, and N. velutinus Fleutiaux, 1891 both from New Caledonia. A comparative study of the morphological characters of males and females, including the reproductive organs of the Nycterilampus species and Tetrigus parallelus Candeze, 1857 (type-species) is presented. A key to Nycterilampus species and their separation from Tetrigus parallelus is given.
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Extant Doras are newly diagnosed among Doradidae by the unique combination of maxillary barbels long and fimbriate; mesethmoid with anterior lateral margins converging towards narrow tip; single anterior cranial fontanel contained largely within frontals and anteriorly by mesethmoid (posterior cranial fontanel occluded); anterior nuchal plate wide, pentaganol or roughly hexagonal, sharing distinct lateral suture with epioccipital and isolating supraoccipital from middle nuchal plate; nuchal foramina absent; coracoid process short, posterior tip falling well short of that of postcleithral process; dentary with acicular teeth; and skin immediately ventral to postcleithral process perforated with conspicuous pores. One fossil species, dagger D. dioneae, and two nominal extant species, D. carinatus and D. micropoeus, are recognized as valid and the latter two redescribed. Three additional extant species, D. phlyzakion, D. higuchii and D. zuanoni, are newly described from the middle Amazon and tributaries, lower Amazon tributaries and rio Araguaia (Tocantins drainage), respectively. Doras phlyzakion and D. zuanoni form a monophyletic group that is found in lowland, lentic habitats, and is characterized by multiple conspicuous pores in skin on breast and abdomen, a trait unique among doradids and rare if not unique among all catfishes. The remaining extant species, D. carinatus, D. higuchii and D. micropoeus, with uncertain relationships, are found in upland, lotic habitats. The occurrence of D. carinatus in the Orinoco basin suggests a historical link between right-bank tributaries of the lower Orinoco (e.g., Caroni) draining the western Guiana Shield and more eastern rivers (e.g., Cuyuni-Essequibo) that drain the Shield directly into the Atlantic Ocean. A key to extant species is provided, a neotype is designated for Silurtis carinatus Linnaeus 1766, and Mormyropsis Miranda Ribeiro, 1911, is placed in the synonymy of Doras Lacepede, 1803.
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Three species of Scorpiodoras are recognized: S. calderonensis, S. heckelii, and S. liophysus; the latter species is described herein. Scorpiodoras calderonensis occurs in the upper Amazon basin, including the Solimoes, Jurua, Japura, and Tefe rivers. Its type locality, originally stated as ""Calderon"", is elucidated as Tabatinga, Brazil. Scorpiodoras heckelii is the most widespread species, occurring in the Orinoco, Branco, Negro, and Amazonas rivers downstream of its confluence with Rio Negro. Scorpiodoras liophysus is only known from the middle Rio Madeira basin and presents a morphological feature unique within the genus: gas bladder without secondary bladder. An osteological description of the genus is provided, as well as redescriptions of S. calderonensis and S. heckelii. Additionally, a key allowing identification of the species is presented, as well as a biogeographic discussion.