Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Ecology ; 104(12): e4174, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37776233

RESUMO

Habitat fragmentation remains a major focus of research by ecologists decades after being put forward as a threat to the integrity of ecosystems. While studies have documented myriad biotic changes in fragmented landscapes, including the local extinction of species from fragments, the demographic mechanisms underlying these extinctions are rarely known. However, many of them-especially in lowland tropical forests-are thought to be driven by one of two mechanisms: (1) reduced recruitment in fragments resulting from changes in the diversity or abundance of pollinators and seed dispersers or (2) increased rates of individual mortality in fragments due to dramatically altered abiotic conditions, especially near fragment edges. Unfortunately, there have been few tests of these potential mechanisms due to the paucity of long-term and comprehensive demographic data collected in both forest fragments and continuous forest sites. Here we report 11 years (1998-2009) of demographic data from populations of the Amazonian understory herb Heliconia acuminata (LC Rich.) found at Brazil's Biological Dynamics of Forest Fragments Project (BDFFP). The data set comprises >66,000 plant × year records of 8586 plants, including 3464 seedlings established after the first census. Seven populations were in experimentally isolated fragments (one in each of four 1-ha fragments and one in each of three 10-ha fragments), with the remaining six populations in continuous forest. Each population was in a 50 × 100 m permanent plot, with the distance between plots ranging from 500 m to 60 km. The plants in each plot were censused annually, at which time we recorded, identified, marked, and measured new seedlings, identified any previously marked plants that died, and recorded the size of surviving individuals. Each plot was also surveyed four to five times during the flowering season to identify reproductive plants and record the number of inflorescences each produced. These data have been used to investigate topics ranging from the way fragmentation-related reductions in germination influence population dynamics to statistical methods for analyzing reproductive rates. This breadth of prior use reflects the value of these data to future researchers. In addition to analyses of plant responses to habitat fragmentation, these data can be used to address fundamental questions in plant demography and the evolutionary ecology of tropical plants and to develop and test demographic models and tools. Though we welcome opportunities to collaborate with interested users, there are no restrictions on the use of this data set. However, we do request that those using the data for teaching or research purposes inform us of how they are doing so and cite this paper and the data archive when appropriate. Any publication using the data must also include a BDFFP Technical Series Number in the Acknowledgments. Authors can request this series number upon the acceptance of their article by contacting the BDFFP's Scientific Coordinator or E. M. Bruna.


Assuntos
Ecossistema , Heliconiaceae , Humanos , Heliconiaceae/fisiologia , Árvores , Florestas , Dinâmica Populacional , Plantas , Plântula , Clima Tropical
2.
Mol Ecol ; 31(17): 4465-4477, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35808851

RESUMO

Forest conversion and habitat loss are major threats to biological diversity. Forest regeneration can mitigate the negative effects of old-growth forest loss on species diversity, but less is known about the extent to which forest loss reduces genetic diversity in remnant populations and whether secondary forests play a role in the maintenance of genetic diversity. We quantified genetic diversity in a tropical hummingbird-pollinated understorey herb, Heliconia tortuosa, across a landscape mosaic of primary and secondary forest regrowth. Using microsatellite genotypes from >850 adult and juvenile plants within 33 forest patches and extensive bird surveys, we examined the effect of contemporary and historical landscape features including forest age (primary vs. secondary forest), stand isolation and pollinator assemblages on genetic diversity and levels of inbreeding in H. tortuosa. We found that inbreeding was up to three times higher in secondary forest, and this effect was amplified with reductions in primary forest in the surrounding landscape through reduced observed heterozygosity in isolated fragments. Inbreeding in forest patches was negatively correlated with the local frequency of specialist long-distance foraging traplining hummingbirds. Traplining hummingbirds therefore appear to facilitate mating among unrelated plants-an inference we tested using empirically parameterized simulations. Higher levels of inbreeding in H. tortuosa are therefore associated with reduced functional diversity of hummingbirds in secondary forests and forest patches isolated from primary forests. Our findings suggest a cryptic consequence of primary forest loss and secondary forest regeneration through the disruption of mutualistic interactions resulting in the erosion of genetic diversity in a common understorey plant.


Assuntos
Heliconiaceae , Animais , Aves/genética , Ecossistema , Florestas , Heliconiaceae/genética , Endogamia , Plantas , Árvores/genética
3.
Zootaxa ; 4999(6): 534-552, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34811327

RESUMO

A new species of the genus Wyeomyia, Wyeomyia (Decamyia) anthica sp. n., is described based on morphological and molecular analyses and is illustrated in larval, pupal and adult life stages. Among the four valid species of the subgenus Decamyia, the new species is closest to Wy. ulocoma (Theobald, 1903), from which it can be distinguished by morphological characters of the male genitalia, larval and pupal stages, and mitochondrial cytochrome c oxidase 1 gene sequence. Wyeomyia ulocoma is recorded from Brazil for the first time.


Assuntos
Culicidae , Heliconiaceae , Animais , Flores , Pupa
4.
J Ethnopharmacol ; 275: 114113, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33852948

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Heliconia rostrata Ruiz and Pav. belongs to the family Heliconiaceae. Plant was traditionally used to cure jaundice, intestinal pain, diabetes and hypertension. AIM OF THE EXPERIMENT: Present study evaluated hepatoprotective efficacy of ethanol (REE) and methanol (RME) extracts of H. rostrata rhizomes in HepG2 cell lines and rats. Antioxidant efficacy of extracts was determined using ex vivo and in vivo methods. MATERIALS AND METHODS: Before conducting efficacy studies, safety of REE and RME was established using toxicity studies which included Oral acute-fixed dose toxicity using OECD TG420, 28-days repeated dose oral toxicity by OECD TG407 and cytotoxicity studies by brine shrimp lethality (BSL) bioassay and MTT assay taking HepG2 cell line. Ex vivo (Extracts: 0-250 µg/ml) and in vivo (Extracts: 50, 100 and 200 mg/kg) antioxidant studies were performed on fresh goat liver and rats (N = 45) of either sex, respectively. In vitro hepatoprotective efficacy of extracts was evaluated against ethanol induced toxicity in HepG2 cell line. In vivo study was performed at 50, 100 and 200 mg/kg/day doses in rats by CCl4-induced hepatotoxicity study. RESULTS: No mortality was observed during single and repeated dose toxicity studies. 50% lethal dose >2000 mg/kg, confirmed category 5 toxicity level of extracts, according to Globally Harmonized System. No signs of toxicity and treatment or dose related changes recorded in rats under repeated dose toxicity study. No-observed-adverse effect-level of 200 mg/kg/day was observed for both extracts. Median lethal concentration of REE and RME were 1291.30 and 1045.89 µg/ml, respectively in BSL bioassay and 50% cytotoxicity concentration >1000 µg/ml was obtained for both extracts from MTT assay. Calculated 50% inhibitory concentration and median effective dose of extracts obtained from different antioxidant assays in ex vivo and in vivo antioxidant studies, respectively indicated REE has more antioxidant efficacy than RME. In in vitro hepatoprotective efficacy study, extracts demonstrated dose dependent protection against ethanol induced hepatotoxicity. At 400 µg/ml, REE and RME demonstrated percentage protection of 65.53% and 57.98%, respectively. Results of liver function test and histopathological evaluation of liver in in vivo hepatoprotective study confirmed dose dependent protection provided by the extracts against CCl4 -induced hepatotoxicity. CONCLUSION: Both REE and RME were found safe to be considered for therapeutic uses. Both REE and RME were found to exhibit antioxidant efficacy in ex vivo and in vivo models. Results ascertained that H. rostrata rhizomes possess significant hepatoprotective potency.


Assuntos
Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Heliconiaceae/química , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Rizoma/química , Animais , Antioxidantes/uso terapêutico , Antioxidantes/toxicidade , Peso Corporal/efeitos dos fármacos , Tetracloreto de Carbono/toxicidade , Morte Celular/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Ensaios Enzimáticos , Etanol/toxicidade , Feminino , Cabras , Células Hep G2 , Humanos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Extratos Vegetais/uso terapêutico , Extratos Vegetais/toxicidade , Substâncias Protetoras/uso terapêutico , Ratos , Soro/química , Soro/efeitos dos fármacos , Silimarina/farmacologia
5.
Zootaxa ; 4830(2): zootaxa.4830.2.4, 2020 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-33056153

RESUMO

Decamyia Dyar is a subgenus of Wyeomyia Theobald with three valid species. Wyeomyia rorotai Senevet, Chabelard Abonnenc, a species originally described rather briefly in the subgenus Dendromyia, is without subgeneric position in the genus. In the present work, we redescribe Wy. rorotai in all life stages and formally define its taxonomic placement in the subgenus Decamyia by combining morphological and molecular analyses based on the mitochondrial cytochrome c oxidase subunit I gene. We also show that Decamyia is a rather homogeneous group of four species, i.e. Wy. ulocoma (Theobald), Wy. pseudopecten Dyar Knab, Wy. felicia Dyar Núñez Tovar and Wy. rorotai, the immature stages of which almost exclusively inhabit the flower bracts of Heliconiaceae.


Assuntos
Culicidae , Heliconiaceae , Animais
6.
Genetics ; 213(2): 581-594, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31467133

RESUMO

Investigating gene expression evolution over micro- and macroevolutionary timescales will expand our understanding of the role of gene expression in adaptation and speciation. In this study, we characterized the evolutionary forces acting on gene expression levels in eye and brain tissue of five Heliconius butterflies with divergence times of ∼5-12 MYA. We developed and applied Brownian motion (BM) and Ornstein-Uhlenbeck (OU) models to identify genes whose expression levels are evolving through drift, stabilizing selection, or a lineage-specific shift. We found that 81% of the genes evolve under genetic drift. When testing for branch-specific shifts in gene expression, we detected 368 (16%) shift events. Genes showing a shift toward upregulation have significantly lower gene expression variance than those genes showing a shift leading toward downregulation. We hypothesize that directional selection is acting in shifts causing upregulation, since transcription is costly. We further uncovered through simulations that parameter estimation of OU models is biased when using small phylogenies and only becomes reliable with phylogenies having ≥ 50 taxa. Therefore, we developed a new statistical test based on BM to identify highly conserved genes (i.e., evolving under strong stabilizing selection), which comprised 3% of the orthoclusters. In conclusion, we found that drift is the dominant evolutionary force driving gene expression evolution in eye and brain tissue in Heliconius Nevertheless, the higher proportion of genes evolving under directional than under stabilizing selection might reflect species-specific selective pressures on vision and the brain that are necessary to fulfill species-specific requirements.


Assuntos
Adaptação Fisiológica/genética , Evolução Molecular , Heliconiaceae/genética , Animais , Encéfalo/crescimento & desenvolvimento , Borboletas/genética , Borboletas/crescimento & desenvolvimento , Olho/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento/genética , Deriva Genética , Variação Genética , Heliconiaceae/crescimento & desenvolvimento , Fenótipo , Filogenia , Especificidade da Espécie
7.
Zootaxa ; 4559(1): 57-89, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30791028

RESUMO

This article documents 91 species-group names of Butterflies (Lepidoptera: Papilionoidea) for which either primary or secondary type material is present in the collections of the National Museums of Scotland, Edinburgh. The describers and the 76 nominal taxa they descibed are as follows: H. Druce (1846-1913) Euphaedra COOKSONI, Mycalesis HAROLDI; H.H. Druce (1869-1922) Cyclopides COOKSONI, Spindasis KALLIMON; H.J. Elwes (1846-1922) Parnassius delphius ssp. INFERNALIS; J.C. Fabricius (1745-1808) Papilio COCALIA ("neotype"), Papilio MARDANIA ("neotype"); H. Fruhstorfer (1866-1922) Parnassius mnemosyne ssp. MELAINA; D.R. Gifford (1918-1981) Leptomyrina HANDMANI, Alaena LAMBORNI, Deudorix (Virachola) MAGDA, Papilio ophidicephalus ssp. MKUWADZI; J.B. Godart (1775-1825) Idea AGELIA, Danais ALCATHOE, Cethosia ALIPHERA, Danais ALOPIA, Danais BAUDINIANA, Papilio BITIAS, Argynnis BRIAREA, Heliconia CLEOBAEA, Danais CLEOPHILE, Danais CLEOTHERA, Heliconia CYRBIA, Pieris DOXO, Pieris EPICHARIS, Pieris ERIPHIA, Heliconia ETHILLA, Heliconia EUCLEA, Papilio EURYMAS, Pieris GIDICA, Argynnis HEGEMONE, Satyrus HYSIUS, Papilio IMERIUS, Acraea JANISCA, Pieris JOSEPHINA, Vanessa LAODORA, Papilio LEUCASPIS, Papilio LYCORAEUS, Vanessa LYTREA, Heliconia MEGARA, Heliconia MELPHIS, Libythea MYRRHA, Acraea OZOMENE, Pieris PHISADIA, Papilio POLYMETUS, Danais PROTHOE, Argynnis PYGMAEA, Pieris PYRO, Pieris SALACIA, Acraea SERVONA, Papilio TEMENES, Papilio TEREAS, Libythea TERENA, Biblis THADANA, Argynnis THAROSSA, Papilio TRIOPAS, Pieris VENILIA, Vanessa VULCANIA, Acraea ZETHEA, Acraea ZIDORA, Acraea ZOSTERIA; C.W.N. Holmes (1916-2018) Bebearia paludicola ssp. BLANDI, Bebearia cocalioides ssp. HECQI, Bebearia orientis ssp. MALAWIENSIS, Bebearia PALUDICOLA; E.G. Honrath (1837-1893) Parnassius bremeri ssp. GRAESERI, Parnassius nordmanni var. MINIMA; W.J. Kaye (1875-1967) Hesperocharis LAMONTI; F. Moore (1830-1907) Neptis ADARA, Abisara ANGULATA, Lebadea ATTENUATA, Ixias CITRINA, Euploea LIMBORGII, Papilio ONPAPE, Cirrhochroa SURYA; W.F.H. Rosenberg G. Talbot (1914) Dismorphia orise ssp. DENIGRATA.        The secondary type material (number of species in brackets) originates from H. Carcasson (1), M. Cock (1), J. B. Godart (7), W. J. Kaye (1), O. Kudrna (3) and M. B. Usher (2).


Assuntos
Borboletas , Heliconiaceae , Lepidópteros , Animais , Museus , Escócia
8.
Biosci. j. (Online) ; 35(1): 222-235, jan./fev. 2019. tab, graf, ilus
Artigo em Inglês | LILACS | ID: biblio-1048575

RESUMO

The growth of the tropical flower market has demanded a consistent search for new varieties, primarily those endowed with an exotic profile, but that are also beautiful and durable. The genusHeliconia, naturally found in the Amazon region, is among the most prominent of tropical flowers. Looking to augment the genetic variability available in Heliconia chartacea var. Sexy Pink, biotechnological research was conducted with the application of colchicine to induce polyploidy in plants from this species. With that in mind, this study was undertaken to evaluate the establishment of plants in the field drawn from in vitro polyploidy induction assay and to determine the morphological and physiological characteristics of 38 H. chartacea var. Sexy Pink clones. The characterization analyzes were performed through 49 morphological descriptors and a stomatal density evaluation using microscopy. The genotype 35 exhibited the greatest morphological variations, with alterations in the position and coloring of the inflorescence, in addition to having the edges of the entire limbus. Genotype 18 featured the lowest amounts for plant height and inflorescence size, showing promise for research geared towards use in reduced environments. Some genotypes did not have any flowering and arerecommended exclusively for landscape composition such as foliage, since their exotic characteristics allow for this. The genotypes that were evaluated displayed stomata with tetracytic morphology and guard cells that had no significant changes. However, genotypes with greater equatorial diameter and stomatal density were obtained in relation to the mother-plant. Overall, the induction of polyploidy allowed for clones to be obtained with a high variability for the characteristics of the leaf, pseudostem and inflorescence, with various attributes that confer a more efficient post-harvest management to some genotypes, in addition to favorable aspects for commercialized purposes as a cut flower.


A expansão do mercado de flores tropicais tem demandado uma constante procura por novas variedades, principalmente aquelas dotadas de perfil exótico, mas ainda apresentando beleza e durabilidade. Dentre as flores tropicais de maior destaque, se encontram as do gênero Helicônia, sendo estas naturalmente encontradas na região Amazônica. Visando aumentar a variabilidade genética disponível em Heliconia chartacea var. Sexy Pink, pesquisas biotecnológicas foram realizadas com a aplicação de colchicina para indução a poliploidia em plantas da espécie. Deste modo, o objetivo do presente trabalho foi avaliar as plantas estabelecidas em campo, provenientes dos ensaios de indução à poliploidia in vitro para determinar as características morfológicas e fisiológicas de 38 clones de H. chartacea var. Sexy Pink. As análises de caracterização foram realizadas por meio de 49 descritores morfológicos e avaliação da densidade estomática por microscopia. O genótipo 35 foi o que apresentou as maiores variações morfológicas, com alterações na posição e coloração da inflorescência, além de possuir as bordas do limbo foliar inteiras. O genótipo 18 apresentou os menores valores para altura da planta e tamanho das inflorescências, mostrando-se promissor para pesquisas voltadas ao uso em ambientes reduzidos. Alguns genótipos não tiveram floração, sendo recomendada a sua utilização exclusivamente para composição paisagística como folhagens, já que sua exoticidade permite esta finalidade. Os genótipos avaliados apresentaram estômatos com morfologia tetracítica e células-guarda sem alterações significativas, porém, foram obtidos genótipos com maior diâmetro equatorial e densidade estomática em relação a planta matriz. De modo geral, a indução a poliploidia permitiu a obtenção de clones com alta variabilidade para características da folha, pseudocaule e inflorescência, sendo vários os atributos que conferiram a alguns genótipos um manejo pós-colheita mais eficiente, além de aspectos favoráveis para comercialização como flor de corte.


Assuntos
Poliploidia , Colchicina , Heliconiaceae , Flores
10.
Artigo em Inglês | MEDLINE | ID: mdl-30596356

RESUMO

In order to investigate the potential of vertical flow constructed wetlands (VFCWs), a 24.5 m2 surface area filled with gravel and planted with Heliconia psittacorum, was implemented as an experimental system for domestic wastewater treatment in southern Brazil. The aims of the study were to (i) evaluate the performance of a full scale system septic tank (ST) and VFCW for decentralized domestic wastewater treatment, and (ii) identify the influence of Heliconia for hydraulic characteristics and consequent performance of the VFCW. The applied load rates in the VFCW were, on average, 10 g biochemical oxygen demand (BOD) m-2 day-1, 4 g NH4+-N m-2 day-1 and a hydraulic loading rate (HLR) of 60 mm day-1. Physicochemical analyses of wastewater treatment were carried out through grab sample methodology, for 5 months. Additionally, hydrodynamic tests were performed during plant development using rhodamine. The study demonstrated the viability of the system for decentralized wastewater treatment in Brazil, with average removal efficiencies of 78% for chemical oxygen demand (COD) and 84% for total suspended solids (TSS), according to national effluent discharge regulations. In spite of media's large size, the VFCW achieved good average removal efficiencies. The tracer test results showed that the VFCW average hydraulic detention time increased as plants grew. This may have occurred due to interception of wastewater applied on the macrophyte's leaves as well as a reduction in filter media permeability caused by the spread of roots and rhizomes. These results indicate that the plants played an important role in increasing wastewater contact time in wetlands with high hydraulic conductivity such as a gravel VFCW.


Assuntos
Heliconiaceae/química , Áreas Alagadas , Análise da Demanda Biológica de Oxigênio , Biomassa , Brasil , Monitoramento Ambiental , Nitrogênio/química , Eliminação de Resíduos Líquidos , Águas Residuárias/química , Águas Residuárias/microbiologia , Microbiologia da Água
11.
Environ Technol ; 38(2): 199-208, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27628332

RESUMO

This study assessed the treatment of domestic wastewater to find the optimum vertical flow-constructed wetland (VFCW) configuration under tropical conditions. Eight pilot-scale configurations units were studied to compare between fine sand and medium gravel used as substrate, two feeding frequencies (20 pulses d-1 and 10 pulses d-1), and the presence or absence of tropical plants (Heliconia psittacorum). The results showed that the sand beds were significantly more efficient in the removal of organic matter, ammonia nitrogen, and total suspended solids than gravel beds, presenting average removal rates of 48 and 24 g m-2 d-1 of COD; 35 and 16 g m-2 d-1 of BOD5; 7 and 4 g m-2 d-1 of [Formula: see text]; 9 and 0 g m-2 d-1 for sand and gravel, respectively. The oxygen consumption rates were calculated and a value of 65 g m-2 d-1 was obtained for sand beds while for the gravel beds the consumption rate was 30 g m-2 d-1. The assessment of different kinds of nitrogen showed interesting dynamics in the nitrification processes. The presence of H. psittacorum showed positive effects in the total nitrogen (TN) removal. The different loading frequencies applied did not show significant statistical differences in the removal of the tested contaminants. Preliminary results were found in the pathogen removal, where the sand is favorable as the substrate. This work represents the first step in the research of optimum VFWC design and operation parameters for Colombia as well as the use of plants of the genus Heliconia.


Assuntos
Heliconiaceae , Eliminação de Resíduos Líquidos/métodos , Áreas Alagadas , Amônia/análise , Compostos de Amônio/análise , Análise da Demanda Biológica de Oxigênio , Colômbia , Desnitrificação , Enterobacteriaceae/isolamento & purificação , Nitrificação , Clima Tropical , Águas Residuárias/análise , Poluentes da Água/análise
12.
Mol Phylogenet Evol ; 117: 150-167, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-27998817

RESUMO

Heliconia (Heliconiaceae, order Zingiberales) is among the showiest plants of the Neotropical rainforest and represent a spectacular co-evolutionary radiation with hummingbirds. Despite the attractiveness and ecological importance of many Heliconia, the genus has been the subject of limited molecular phylogenetic studies. We sample seven markers from the plastid and nuclear genomes for 202 samples of Heliconia. This represents ca. 75% of accepted species and includes coverage of all taxonomic subgenera and sections. We date this phylogeny using fossils associated with other families in the Zingiberales; in particular we review and evaluate the Eocene fossil Ensete oregonense. We use this dated phylogenetic framework to evaluate the evolution of two components of flower orientation that are hypothesized to be important for modulating pollinator discrimination and pollen placement: resupination and erect versus pendant inflorescence habit. Our phylogenetic results suggest that the monophyletic Melanesian subgenus Heliconiopsis and a small clade of Ecuadorian species are together the sister group to the rest of Heliconia. Extant diversity of Heliconia originated in the Late Eocene (39Ma) with rapid diversification through the Early Miocene, making it the oldest known clade of hummingbird-pollinated plants. Most described subgenera and sections are not monophyletic, though closely related groups of species, often defined by shared geography, mirror earlier morphological cladistic analyses. Evaluation of changes in resupination and inflorescence habit suggests that these characters are more homoplasious than expected, and this largely explains the non-monophyly of previously circumscribed subgenera, which were based on these characters. We also find strong evidence for the correlated evolution of resupination and inflorescence habit. The correlated model suggests that the most recent common ancestor of all extant Heliconia had resupinate flowers and erect inflorescences. Finally, we note our nearly complete species sampling and dated phylogeny allow for an assessment of taxonomic history in terms of phylogenetic diversity. We find approximately half of the currently recognized species, corresponding to half of the phylogenetic diversity, have been described since 1975, highlighting the continued importance of basic taxonomic research and conservation initiatives to preserve both described and undiscovered species of Heliconia.


Assuntos
Flores/anatomia & histologia , Flores/genética , Heliconiaceae/anatomia & histologia , Heliconiaceae/genética , Filogenia , Núcleo Celular/genética , Fósseis , Mapeamento Geográfico , Inflorescência/anatomia & histologia , Inflorescência/genética , Plastídeos/genética , Polinização
13.
Ecology ; 98(2): 370-381, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27870009

RESUMO

Temporal variability in light from gaps in the tree canopy strongly influences the vital rates of understory plants. From 2012 to 2015, we estimated the size-specific vital rates of two herbs, Calathea crotalifera and Heliconia tortuosa, over a range of light environments. We estimated maximum photosynthetic capacity (Amax ) for a subset of individuals each year during three annual censuses, and modelled future size as a linear function of current size (a plant trait that changes ontogenetically), canopy openness (an environmental variable), and Amax (a potentially plastic physiological trait). We estimated what the demographic success would be of a population comprised of individuals with a particular fixed Amax for each of several levels of canopy openness if the environment remained constant, by evaluating corresponding Integral Projection Models and their deterministic growth rates (λ). We then estimated their demographic success in the stochastic light environment (λS ) and its elasticities. As light increased, deterministic λ increased for Calathea by 33% but decreased for Heliconia by 52%, and increasing Amax had no effect on λ for Calathea but increased λ for Heliconia in low light. As Amax increased, λS increased for Heliconia, but not Calathea. We also investigated whether photosynthetic rates would influence the elasticities of λS, including its response to perturbation of vital rates in each environment (ESß ), vital rates over all environments (ES ), and variability of vital rates among environments (ESσ ). ES , ESσ , and ESß were influenced by Amax for Heliconia but not Calathea. Events that affect some vital rates in high light have a greater impact on overall fitness than events that affect the same vital rates in shady environments, and there is greater potential for selection on traits of large individuals in high light than in low light for Heliconia, while the reverse was true for Calathea. Photosynthetic rates, through their effects on growth, can strongly influence the population dynamics of plants in random light environments, but the magnitude of this effect varies between species. In the species for which fitness was independent of Amax , Calathea, there would be little opportunity for selection on photosynthetic rates.


Assuntos
Florestas , Fotossíntese , Heliconiaceae , Folhas de Planta , Dinâmica Populacional , Luz Solar , Árvores
14.
Environ Pollut ; 218: 923-930, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27554980

RESUMO

Mounting evidence has shown that an alteration of the gut microbiota is associated with diet, and plays an important role in animal health and metabolic diseases. However, little is known about the influence of environmental contaminants on the gut microbial community. Bisphenol A (BPA), which is widely used for manufacturing plastic products, has recently been classified as an environmental obesogen. Although many studies have demonstrated the metabolic-disrupting effects of BPA on liver and pancreatic functions, the possible effects of this synthetic compound on the metabolic diversity of the intestinal microbiota is unknown. Using 16S rRNA gene sequencing analysis on caecum samples of CD-1 mice, the present study aimed to test the hypothesis that dietary BPA intake may influence the gut microbiota composition and functions, an important attributing factor to development of the metabolic syndrome. A high-fat diet (HFD) and high-sucrose diet (HSD) were included as the positive controls for comparing the changes in the intestinal microbial profiles. Our results demonstrated a significant reduction of species diversity in the gut microbiota of BPA-fed mice. Alpha and beta diversity analyses showed that dietary BPA intake led to a similar gut microbial community structure as that induced by HFD and HSD in mice. In addition, comparative analysis of the microbial communities revealed that both BPA and a HFD favored the growth of Proteobacteria, a microbial marker of dysbiosis. Consistently, growth induction of the family Helicobacteraceae and reduction of the Firmicutes and Clostridia populations were observed in the mice fed BPA or a HFD. Collectively, our study highlighted that the effects of dietary BPA intake on the shift of microbial community structure were similar to those of a HFD and HSD, and revealed microbial markers for the development of diseases associated with an unstable microbiota.


Assuntos
Compostos Benzidrílicos/toxicidade , Dieta Hiperlipídica/efeitos adversos , Poluentes Ambientais/toxicidade , Microbioma Gastrointestinal/genética , Intestinos/microbiologia , Metagenômica/métodos , Fenóis/toxicidade , Animais , Compostos Benzidrílicos/farmacocinética , Clostridium/genética , Clostridium/crescimento & desenvolvimento , Poluentes Ambientais/farmacocinética , Heliconiaceae/genética , Heliconiaceae/crescimento & desenvolvimento , Mucosa Intestinal/metabolismo , Intestinos/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Microbiota/genética , Fenóis/farmacocinética , Proteobactérias/genética , Proteobactérias/crescimento & desenvolvimento , RNA Ribossômico 16S/genética
15.
Genet Mol Res ; 15(2)2016 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-27420942

RESUMO

The Neotropical Heliconia genus contains highly diversified plants and up to 220 species have been reported from the north of Mexico to the South of Brazil. Heliconia are cultivated as ornamental garden plants and as cut flowers. All species can be propagated by seeds or vegetatively, through rhizomes. Depending on the species, an individual plant can spread and form large clonal populations. H. bihai L., H. chartacea Lane ex Barreiros, and H. wagneriana Petersen are among the most cultivated Heliconia species. However, they still have undesirable characteristics that could be improved for the international market. This study aimed to characterize 15 half-sib families originating from commercial cultivations, by morphological and molecular markers. The genetic diversity (HE), considering all individuals of the three species was 0.103. For H. bihai half-sib families, the value of HE was 0.242, showing high genetic diversity. The HE value for H. chartacea was 0.068, indicating low genetic diversity. All individuals of H. wagneriana showed the same band patterns, suggesting that the two parental plants were propagated vegetatively from the same plant and may have undergone some endogamic crossings. These results showed that molecular characterization can differentiate individuals closely related as half-siblings for H. bihai and H. chartacea, despite the low variation observed with morphological descriptors. The high genetic diversity observed in H. bihai half-sibling genotypes can provide valuable resources for breeding programs.


Assuntos
Especiação Genética , Variação Genética , Heliconiaceae/genética , Heliconiaceae/classificação , Endogamia
16.
Genome Biol ; 17: 25, 2016 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-26921238

RESUMO

BACKGROUND: Although hybridization is thought to be relatively rare in animals, the raw genetic material introduced via introgression may play an important role in fueling adaptation and adaptive radiation. The butterfly genus Heliconius is an excellent system to study hybridization and introgression but most studies have focused on closely related species such as H. cydno and H. melpomene. Here we characterize genome-wide patterns of introgression between H. besckei, the only species with a red and yellow banded 'postman' wing pattern in the tiger-striped silvaniform clade, and co-mimetic H. melpomene nanna. RESULTS: We find a pronounced signature of putative introgression from H. melpomene into H. besckei in the genomic region upstream of the gene optix, known to control red wing patterning, suggesting adaptive introgression of wing pattern mimicry between these two distantly related species. At least 39 additional genomic regions show signals of introgression as strong or stronger than this mimicry locus. Gene flow has been on-going, with evidence of gene exchange at multiple time points, and bidirectional, moving from the melpomene to the silvaniform clade and vice versa. The history of gene exchange has also been complex, with contributions from multiple silvaniform species in addition to H. besckei. We also detect a signature of ancient introgression of the entire Z chromosome between the silvaniform and melpomene/cydno clades. CONCLUSIONS: Our study provides a genome-wide portrait of introgression between distantly related butterfly species. We further propose a comprehensive and efficient workflow for gene flow identification in genomic data sets.


Assuntos
Especiação Genética , Heliconiaceae/genética , Hibridização Genética , Animais , Genoma de Inseto , Especificidade da Espécie , Asas de Animais
17.
PLoS One ; 11(1): e0146431, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26814810

RESUMO

Optimal foraging models of floral divergence predict that competition between two different types of pollinators will result in partitioning, increased assortative mating, and divergence of two floral phenotypes. We tested these predictions in a tropical plant-pollinator system using sexes of purple-throated carib hummingbirds (Anthracothorax jugularis) as the pollinators, red and yellow inflorescence morphs of Heliconia caribaea as the plants, and fluorescent dyes as pollen analogs in an enclosed outdoor garden. When foraging alone, males exhibited a significant preference for the yellow morph of H. caribaea, whereas females exhibited no preference. In competition, males maintained their preference for the yellow morph and through aggression caused females to over-visit the red morph, resulting in resource partitioning. Competition significantly increased within-morph dye transfer (assortative mating) relative to non-competitive environments. Competition and partitioning of color morphs by sexes of purple-throated caribs also resulted in selection for floral divergence as measured by dye deposition on stigmas. Red and yellow morphs did not differ significantly in dye deposition in the competition trials, but differences in dye deposition and preferences for morphs when sexes of purple-throated caribs foraged alone implied fixation of one or the other color morph in the absence of competition. Competition also resulted in selection for divergence in corolla length, with the red morph experiencing directional selection for longer corollas and the yellow morph experiencing stabilizing selection on corolla length. Our results thus support predictions of foraging models of floral divergence and indicate that pollinator competition is a viable mechanism for divergence in floral traits of plants.


Assuntos
Aves/fisiologia , Polinização/fisiologia , Animais , Comportamento Competitivo , Feminino , Flores/fisiologia , Heliconiaceae/crescimento & desenvolvimento , Masculino , Fenótipo , Pólen/fisiologia , Viés de Seleção
18.
Braz J Biol ; 75(4): 859-67, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26628227

RESUMO

The occurrence of Myxomycetes in Heliconia psittacorum L.f. inflorescences was researched within four conservation units located in Northeast Brazil, aiming at evaluating the occupation of this microhabitat in fragments of Atlantic Forest along an altitude between 30-750 m. Inflorescences attached to the plant were examined; dead flowers and bracts were collected to assemble moist chambers (368). Four families, four genera and 10 species were recorded. A preference was evidenced for a basic pH substrate and a predominance of calcareous species (5:1). The composition of the myxobiota in fragments pertaining to altitudes above 400 m was similar and differed significantly from the one found in fragments of lowland forests (<100 m). Physarum compressum and Arcyria cinerea are the most characteristic species of the studied myxobiota.


Assuntos
Florestas , Heliconiaceae , Mixomicetos/fisiologia , Brasil , Inflorescência/crescimento & desenvolvimento
19.
Braz. j. biol ; 75(4): 859-867, Nov. 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-768217

RESUMO

Abstract The occurrence of Myxomycetes in Heliconia psittacorum L.f. inflorescences was researched within four conservation units located in Northeast Brazil, aiming at evaluating the occupation of this microhabitat in fragments of Atlantic Forest along an altitude between 30-750 m. Inflorescences attached to the plant were examined; dead flowers and bracts were collected to assemble moist chambers (368). Four families, four genera and 10 species were recorded. A preference was evidenced for a basic pH substrate and a predominance of calcareous species (5:1). The composition of the myxobiota in fragments pertaining to altitudes above 400 m was similar and differed significantly from the one found in fragments of lowland forests (<100 m). Physarum compressum and Arcyria cinerea are the most characteristic species of the studied myxobiota.


Resumo A ocorrência de mixomicetos em inflorescências de Heliconia psittacorum L.f. foi pesquisada em quatro unidades de conservação situadas no Nordeste do Brasil, visando avaliar a ocupação deste microhabitat em fragmentos de Floresta Atlântica, numa faixa altitudinal de 30-750 m. Foram examinadas partes mortas de inflorescências ainda presas à planta; flores e brácteas mortas foram colhidas para montagem de câmaras-úmidas (368). Foram registrados quatro famílias, quatro gêneros e 10 espécies. Evidenciou-se preferência para substrato com pH básico e predominância de espécies calcárias (5:1). A composição da mixobiota nos fragmentos de altitudes acima de 400 m foi semelhante e diferiu significativamente da encontrada nos fragmentos de florestas de terras baixas (<100 m). Physarum compressum e Arcyria cinerea são as espécies mais características da mixobiota estudada.


Assuntos
Florestas , Heliconiaceae , Mixomicetos/fisiologia , Brasil , Inflorescência/crescimento & desenvolvimento
20.
Am J Bot ; 102(8): 1290-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26290552

RESUMO

UNLABELLED: • PREMISE OF THE STUDY: For tropical forest understory plants, the ability to grow, survive, and reproduce is limited by the availability of light. The extent to which reproduction incurs a survival or growth cost may change with light availability, plant size, and adaptation to shade, and may vary among similar species.• METHODS: We estimated size-specific rates of growth, survival, and reproduction (vital rates), for two neotropical understory herbs (order Zingiberales) in a premontane tropical rainforest in Costa Rica. During three annual censuses we monitored 1278 plants, measuring leaf area, number of inflorescences, and canopy openness. We fit regression models of all vital rates and evaluated them over a range of light levels. The best fitting models were selected using Akaike's Information Criterion.• KEY RESULTS: All vital rates were significantly influenced by size in both species, but not always by light. Increasing light resulted in higher growth and a higher probability of reproduction in both species, but lower survival in one species. Both species grew at small sizes but shrank at larger sizes. The size at which shrinkage began differed among species and light environments. Vital rates of large individuals were more sensitive to changes in light than small individuals.• CONCLUSIONS: Increasing light does not always positively influence vital rates; the extent to which light affects vital rates depends on plant size. Differences among species in their abilities to thrive under different light conditions and thus occupy distinct niches may contribute to the maintenance of species diversity.


Assuntos
Ecossistema , Heliconiaceae/fisiologia , Marantaceae/fisiologia , Costa Rica , Heliconiaceae/crescimento & desenvolvimento , Inflorescência/crescimento & desenvolvimento , Inflorescência/fisiologia , Marantaceae/crescimento & desenvolvimento , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Floresta Úmida , Análise de Regressão , Reprodução , Clima Tropical
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...