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Estruturas secretoras florais em espécies de Leguminosae = : Floral secretory structures in species of Leguminosae; Floral secretory structures in species of Leguminosae

Cristina Ribeiro Marinho
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 24/06/2013 PT
Relevância na Pesquisa
36.27%
Apesar de a família Leguminosae ser rica em espécies, exibir ampla distribuição geográfica e grande variação morfológica, seus representantes têm sido pouco estudados em termos de estruturas secretoras florais. Tais estruturas podem estar localizadas em diferentes partes da flor e estão associadas à atração de polinizadores e/ ou defesa. As flores polinizadas por animais exalam odores que são produzidos e liberados por meio de glândulas de odor ou osmóforos, estruturas que apresentam grande variedade morfológica. Estudos anatômicos de tais glândulas são importantes, pois além de fornecerem informações para o entendimento das interações ecológicas de plantas e seus polinizadores, podem fornecer dados que auxiliem na determinação de relações filogenéticas entre as espécies. Assim, este trabalho objetivou (1) identificar as estruturas secretoras presentes nas flores de espécies de Leguminosae com polinização noturna, (2) levantar caracteres anatômicos florais compartilhados por essas espécies, (3) determinar se existem relações entre a polinização diurna e noturna e a morfologia dos osmóforos em Leguminosae (4) e investigar se os tricomas secretores podem atuar como osmóforos. Botões florais e flores de 14 espécies zoófilas de Leguminosae foram fixados e processados para análises em microscopias de luz...

Resource Heterogeneity Moderates the Biodiversity-Function Relationship in Real World Ecosystems

Tylianakis, Jason M; Rand, Tatyana A; Kahmen, Ansgar; Klein, Alexandra-Maria; Buchmann, Nina; Perner, Jörg; Tscharntke, Teja
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.04%
Numerous recent studies have tested the effects of plant, pollinator, and predator diversity on primary productivity, pollination, and consumption, respectively. Many have shown a positive relationship, particularly in controlled experiments, but variability in results has emphasized the context-dependency of these relationships. Complementary resource use may lead to a positive relationship between diversity and these processes, but only when a diverse array of niches is available to be partitioned among species. Therefore, the slope of the diversity-function relationship may change across differing levels of heterogeneity, but empirical evaluations of this pattern are lacking. Here we examine three important functions/properties in different real world (i.e., nonexperimental) ecosystems: plant biomass in German grasslands, parasitism rates across five habitat types in coastal Ecuador, and coffee pollination in agroforestry systems in Indonesia. We use general linear and structural equation modeling to demonstrate that the effect of diversity on these processes is context dependent, such that the slope of this relationship increases in environments where limiting resources (soil nutrients, host insects, and coffee flowers, respectively) are spatially heterogeneous. These real world patterns...

Characterization and Coding of Behaviorally Significant Odor Mixtures

Riffell, Jeffrey A.; Lei, Hong; Christensen, Thomas A.; Hildebrand, John G.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 24/02/2009 EN
Relevância na Pesquisa
35.82%
For animals to execute odor-driven behaviors, the olfactory system must process complex odor signals and maintain stimulus identity in the face of constantly changing odor intensities [1–5]. Surprisingly, how the olfactory system maintains identity of complex odors is unclear [6–10]. We took advantage of the plant-pollinator relationship between the Sacred Datura (Datura wrightii) and the moth Manduca sexta [11, 12] to determine how olfactory networks in this insect’s brain represent odor mixtures. We combined gas chromatography and neural-ensemble recording in the moth’s antennal lobe to examine population codes for the floral mixture and its fractionated components. Although the floral scent of D. wrightii comprises at least 60 compounds, only nine of those elicited robust neural responses. Behavioral experiments confirmed that these nine odorants mediate flower-foraging behaviors, but only as a mixture. Moreover, the mixture evoked equivalent foraging behaviors over a 1000-fold range in dilution, suggesting a singular percept across this concentration range. Furthermore, neural-ensemble recordings in the moth’s antennal lobe revealed that reliable encoding of the floral mixture is organized through synchronized activity distributed across a population of glomerular coding units...

Floral symmetry: pollinator-mediated stabilizing selection on flower size in bilateral species

Gong, Yan-Bing; Huang, Shuang-Quan
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.22%
Pollinator-mediated stabilizing selection (PMSS) has been proposed as the driver of the evolutionary shift from radial to bilateral symmetry of flowers. Studies have shown that variation in flower size is lower in bilateral than in radial species, but whether bilateral flowers experience more stabilizing selection pressures by employing fewer, more specialized pollinators than radial flowers remains unclear. To test the PMSS hypothesis, we investigate plant–pollinator interactions from a whole community in an alpine meadow in Hengduan Mountains, China, to examine: (i) variance in flower size and level of ecological generalization (pollinator diversity calculated using functional groups) in 14 bilateral and 13 radial species and (ii) the role pollinator diversity played in explaining the difference of variance in flower size between bilateral and radial species. Our data showed that bilateral species had less variance in flower size and were visited by fewer pollinator groups. Pollinator diversity accounted for up to 40 per cent of the difference in variance in flower size between bilateral and radial species. The mediator effect of pollinator diversity on the relationship between floral symmetry and variance in flower size in the community is consistent with the PMSS hypothesis.

Diverse pollinator communities enhance plant reproductive success

Albrecht, Matthias; Schmid, Bernhard; Hautier, Yann; Müller, Christine B.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.42%
Understanding the functional consequences of biodiversity loss is a major goal of ecology. Animal-mediated pollination is an essential ecosystem function and service provided to mankind. However, little is known how pollinator diversity could affect pollination services. Using a substitutive design, we experimentally manipulated functional group (FG) and species richness of pollinator communities to investigate their consequences on the reproductive success of an obligate out-crossing model plant species, Raphanus sativus. Both fruit and seed set increased with pollinator FG richness. Furthermore, seed set increased with species richness in pollinator communities composed of a single FG. However, in multiple-FG communities, highest species richness resulted in slightly reduced pollination services compared with intermediate species richness. Our analysis indicates that the presence of social bees, which showed roughly four times higher visitation rates than solitary bees or hoverflies, was an important factor contributing to the positive pollinator diversity–pollination service relationship, in particular, for fruit set. Visitation rate at different daytimes, and less so among flower heights, varied among social bees, solitary bees and hoverflies...

Linking Plant Specialization to Dependence in Interactions for Seed Set in Pollination Networks

Tur, Cristina; Castro-Urgal, Rocío; Traveset, Anna
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 30/10/2013 EN
Relevância na Pesquisa
36.17%
Studies on pollination networks have provided valuable information on the number, frequency, distribution and identity of interactions between plants and pollinators. However, little is still known on the functional effect of these interactions on plant reproductive success. Information on the extent to which plants depend on such interactions will help to make more realistic predictions of the potential impacts of disturbances on plant-pollinator networks. Plant functional dependence on pollinators (all interactions pooled) can be estimated by comparing seed set with and without pollinators (i.e. bagging flowers to exclude them). Our main goal in this study was thus to determine whether plant dependence on current insect interactions is related to plant specialization in a pollination network. We studied two networks from different communities, one in a coastal dune and one in a mountain. For ca. 30% of plant species in each community, we obtained the following specialization measures: (i) linkage level (number of interactions), (ii) diversity of interactions, and (iii) closeness centrality (a measure of how much a species is connected to other plants via shared pollinators). Phylogenetically controlled regression analyses revealed that...

Fire Promotes Pollinator Visitation: Implications for Ameliorating Declines of Pollination Services

Van Nuland, Michael E.; Haag, Elliot N.; Bryant, Jessica A. M.; Read, Quentin D.; Klein, Robert N.; Douglas, Morgan J.; Gorman, Courtney E.; Greenwell, Trey D.; Busby, Mark W.; Collins, Jonathan; LeRoy, Joseph T.; Schuchmann, George; Schweitzer, Jennifer
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 12/11/2013 EN
Relevância na Pesquisa
26.27%
Pollinators serve critical roles for the functioning of terrestrial ecosystems, and have an estimated annual value of over $150 billion for global agriculture. Mounting evidence from agricultural systems reveals that pollinators are declining in many regions of the world, and with a lack of information on whether pollinator communities in natural systems are following similar trends, identifying factors which support pollinator visitation and services are important for ameliorating the effects of the current global pollinator crisis. We investigated how fire affects resource structure and how that variation influences floral pollinator communities by comparing burn versus control treatments in a southeastern USA old-field system. We hypothesized and found a positive relationship between fire and plant density of a native forb, Verbesina alternifolia, as well as a significant difference in floral visitation of V. alternifolia between burn and control treatments. V. alternifolia density was 44% greater and floral visitation was 54% greater in burned treatments relative to control sites. When the density of V. alternifolia was experimentally reduced in the burn sites to equivalent densities observed in control sites, floral visitation in burned sites declined to rates found in control sites. Our results indicate that plant density is a proximal mechanism by which an imposed fire regime can indirectly impact floral visitation...

Pollinator Interactions with Yellow Starthistle (Centaurea solstitialis) across Urban, Agricultural, and Natural Landscapes

Leong, Misha; Kremen, Claire; Roderick, George K.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 17/01/2014 EN
Relevância na Pesquisa
26.28%
Pollinator-plant relationships are found to be particularly vulnerable to land use change. Yet despite extensive research in agricultural and natural systems, less attention has focused on these interactions in neighboring urban areas and its impact on pollination services. We investigated pollinator-plant interactions in a peri-urban landscape on the outskirts of the San Francisco Bay Area, California, where urban, agricultural, and natural land use types interface. We made standardized observations of floral visitation and measured seed set of yellow starthistle (Centaurea solstitialis), a common grassland invasive, to test the hypotheses that increasing urbanization decreases 1) rates of bee visitation, 2) viable seed set, and 3) the efficiency of pollination (relationship between bee visitation and seed set). We unexpectedly found that bee visitation was highest in urban and agricultural land use contexts, but in contrast, seed set rates in these human-altered landscapes were lower than in natural sites. An explanation for the discrepancy between floral visitation and seed set is that higher plant diversity in urban and agricultural areas, as a result of more introduced species, decreases pollinator efficiency. If these patterns are consistent across other plant species...

Biological studies on japanese bees - IX. Relationship between bees and flowers (part.2)

Miyamoto, Setsu
Fonte: INRA - Instituto Nacional de Investigação Agronômica da França Publicador: INRA - Instituto Nacional de Investigação Agronômica da França
Tipo: Journal Article-postprint
JA; ENGLISH
Relevância na Pesquisa
56.13%
To understand the exact relation between bees and flowers, further biological studies have been made in ten observation areas described in the previous paper. In this paper the following phenomena are taken into consideration. 1) From the studies on the correlation between bees and flowers in each area, flowering plants are distinguished into two types, those visited by a large number of bee species and those by a small number. From April to June, the flowering plants visited by the largest number of bee species are as follows : Brassica campestris subsp.>Astragalus sinicus> Ranunculus acris. But some differences are recognized in the personnel or species-construction of visitors to each flower species. On the other hand, the species which visits the greatest number of flowering plant species during April to June is Halictus scitulus, followed by Anthophora acervolum villosula>Bombus diversus>Bombus ardens. In other words, these bees are the most dominant pollinators in this district. But there are some differences between two kinds of species-construction of flowering plants visited by the bees belonging to Halictidae, and by the bees belonging to Bombidae or Anthophoridae (Table 1). 2) The seasonal transition of the species of visitors to each species of flowering plants were studied from the standpoint of both quantity and quality (Tables 2-7). For each species of flowering plants...

Biological studies on japanese bees - VIII. Relationship between bees and flowers (part.1)

Miyamoto, Setsu
Fonte: INRA - Instituto Nacional de Investigação Agronômica da França Publicador: INRA - Instituto Nacional de Investigação Agronômica da França
Tipo: Journal Article-postprint
JA
Relevância na Pesquisa
46.05%

Biological studies on japanese bees - X. Differences in flower relationships between a japanese and an european honeybees

Miyamoto, Setsu
Fonte: INRA - Instituto Nacional de Investigação Agronômica da França Publicador: INRA - Instituto Nacional de Investigação Agronômica da França
Tipo: Journal Article-postprint
EN
Relevância na Pesquisa
35.82%

Biological studies on japanese bees - XII. Flowers relationships of five species of bees belonging to the genus osmia

Miyamoto, Setsu
Fonte: INRA - Instituto Nacional de Investigação Agronômica da França Publicador: INRA - Instituto Nacional de Investigação Agronômica da França
Tipo: Journal Article-postprint
EN
Relevância na Pesquisa
35.82%

Mating patterns and pollinator mobility are critical traits in forest fragmentation genetics

Breed, M.; Ottewell, K.; Gardner, M.; Marklund, M.; Dormontt, E.; Lowe, A.
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em //2015 EN
Relevância na Pesquisa
46.24%
Most woody plants are animal-pollinated, but the global problem of habitat fragmentation is changing the pollination dynamics. Consequently, the genetic diversity and fitness of the progeny of animal-pollinated woody plants sired in fragmented landscapes tend to decline due to shifts in plant-mating patterns (for example, reduced outcrossing rate, pollen diversity). However, the magnitude of this mating-pattern shift should theoretically be a function of pollinator mobility. We first test this hypothesis by exploring the mating patterns of three ecologically divergent eucalypts sampled across a habitat fragmentation gradient in southern Australia. We demonstrate increased selfing and decreased pollen diversity with increased fragmentation for two small-insect-pollinated eucalypts, but no such relationship for the mobile-bird-pollinated eucalypt. In a meta-analysis, we then show that fragmentation generally does increase selfing rates and decrease pollen diversity, and that more mobile pollinators tended to dampen these mating-pattern shifts. Together, our findings support the premise that variation in pollinator form contributes to the diversity of mating-pattern responses to habitat fragmentation.; MF Breed, KM Ottewell, MG Gardner...

An interesting method of pollen collecting by bees from flowers with tubular anthers

Michener, Charles D.
Fonte: INRA - Instituto Nacional de Investigação Agronômica da França Publicador: INRA - Instituto Nacional de Investigação Agronômica da França
Tipo: Journal Article-postprint
EN; ENGLISH
Relevância na Pesquisa
35.82%
Varous plants have anthers which open by apical pores; in some (Cassia in the Leguminosae and Solanum wendlandii in the Solanaceae ) the pollen does not readily come out of these pores, yet is abundant and is collected and used by females of certain large and moderate sized bees. A bee obtains pollen by curling its body over the ends of the anthers and then vibrating its wings (wings held in folded position). The vibrations, which produce a loud sound, cause the pollen grains to shoot out of the pores in the anthers ; many of them lodge on the body of the bee from which they are transferred to the pollen-carrying scopal hairs. A vibrating knife blade touched to the anthers also causes pollen to be discharged through the pores. The bees concerned are all polylectic, i.e., they obtain palIen from many different plants. Most individuals of most of the species never have an opportunity to use the collecting method described above. The potentiality to learn this method must be inherent in a number of groups of bees, but so far as known is absent in others such as Apis.

Interação planta-polinizador em espécies sincronopátricas de psychotria (rubiaceae); Plant-pollinator interactions in syncronopatric species of psychotria (rubiaceae)

Mesquita Neto, José Neiva
Fonte: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Biodiversidade Vegetal (ICB); Instituto de Ciências Biológicas - ICB (RG) Publicador: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Biodiversidade Vegetal (ICB); Instituto de Ciências Biológicas - ICB (RG)
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
46.26%
Plant-pollinator interactions in syncronopatric species of Psychotria (Rubiaceae). Psychotria species are commonly found in the understory of forested areas in tropical regions, and are important components for the functioning of these ecosystems. Many species of the genus are sympatric and bloom during the same period, being considered potentially syncronopatrics. For this reason, this genus has been considered as a good model to infer general patterns and mechanisms of speciation in the tropics. In the first paper of this dissertation, the interactions between potentially sympatric species of Psychotria and their pollinators were analyzed in order to verify the possible existence of sharing, specialization or generalization of pollinators and plants in the analyzed system. Then, data of secondary studies that contained identifying pollinators of Psychotria were analyzed From these data, we generated graphs and analyzes of interaction networks and niche overlap. Altogether, nine species of Psychotria and 25 species of pollinators of occurrence in the Atlantic Forest were included in the analyzes. The plant with the most generalist network is Psychotria tenuinervis and the pollinators with the highest proportion of links and consequently with more important role in the network belonged orders Lepidoptera and Hymenoptera. Psychotria species showed niche overlap in pollination and pollinator sharing. The period of greatest intensity of flowering coincided with the rainy season in the Atlantic Forest...

Interacciones planta-polinizador desde la perspectiva de los polinizadores: diversidad floral, reproducción de abejas solitarias y su especialización; Plant-pollinator interactions from the pollinator´s perspective: floral diversity, solitary bee reproduction and its specialization

Dorado, Jimena
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2011 SPA
Relevância na Pesquisa
66.41%
La mayoría de los estudios planta-polinizador se centran en las plantas; en esta tesis fueron estudiadas desde la perspectiva de los polinizadores. Primero se evaluó la relación diversidadestabilidad para la producción floral como recurso para los polinizadores a lo largo de una temporada de floración. Los resultados mostraron una relación positiva que permite evaluar la generalidad de esta relación. Además, se evaluó el efecto de medidas ecológicas simples y comúnmente utilizadas, como la diversidad y abundancia floral, sobre el éxito reproductivo de los polinizadores, obteniéndose una respuesta especie específica. Existen dos mecanismos que explican la ampliación del nicho poblacional, pero solo uno de ellos ha sido evaluado proponiendose como el mecanismo general. Aquí, se evaluaron ambos mecanismos sobre varias especies de abeja con resultados diferentes a los reportados previamente, ya que ambos mecanismos operan. Por último, se evaluó cuán confiables son las inferencias sobre las especies raras en las redes planta-polinizador ya que podrían estar sesgadas por el tipo de muestreo utilizado para construirlas. Este estudio demostró que el sesgo existe y que aumenta con la rareza de las especies. Esta tesis permitió avanzar en el conocimiento de las interacciones planta-polinizador...

La pollinisation du lavandin - I. : Ses effets sur les fleurs; Lavandin pollination - I. : Its effects on flowers

Barbier, M.E.C.
Fonte: INRA - Instituto Nacional de Investigação Agronômica da França Publicador: INRA - Instituto Nacional de Investigação Agronômica da França
Tipo: Journal Article-postprint
FR
Relevância na Pesquisa
35.9%

Yeasts in floral nectar: a quantitative survey

Herrera, Carlos M.; Vega, Clara de; Canto, Azucena; Pozo, María I.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artículo Formato: 200876 bytes; application/pdf
ENG
Relevância na Pesquisa
26.19%
9 pages, 2 figures, 4 tables, 1 appendix.-- PMID: 19208669 [PubMed].-- Printed version published Jun 2009.; Supporting information available: List of the 130 plant species included in the survey of yeasts in floral nectar.-- Available at: http://aob.oxfordjournals.org/cgi/content/full/mcp026/DC1; [Background and Aims] One peculiarity of floral nectar that remains relatively unexplored from an ecological perspective is its role as a natural habitat for micro-organisms. This study assesses the frequency of occurrence and abundance of yeast cells in floral nectar of insect-pollinated plants from three contrasting plant communities on two continents. Possible correlations between interspecific differences in yeast incidence and pollinator composition are also explored.; [Methods] The study was conducted at three widely separated areas, two in the Iberian Peninsula (Spain) and one in the Yucatán Peninsula (Mexico). Floral nectar samples from 130 species (37–63 species per region) in 44 families were examined microscopically for the presence of yeast cells. For one of the Spanish sites, the relationship across species between incidence of yeasts in nectar and the proportion of flowers visited by each of five major pollinator categories was also investigated.; [Key Results] Yeasts occurred regularly in the floral nectar of many species...

Relationship between floral colour and pollinator composition in four plant communities

Reverté Saiz, Sara; Bosch Gras, Jordi; Retana Alumbreros, Javier
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em //2014 ENG
Relevância na Pesquisa
36.4%
Pollinators use a variety of floral cues to locate resources, but the relative importance of these different cues on pollinator foraging decisions is unclear. However, floral colour is undoubtedly one of the most important, as evidenced in previous works revealing the importance of floral colour on pollinator choices and determining flower visitor composition. Our purpose is to establish whether there is a relationship between flower colour and pollinator composition in natural communities. We measured the floral reflectance spectrum of 109 plant populations, from 300 to 700 nm, and divided it in four broad bands of 100 nm each. We found a phylogenetic signal on floral colour variables, and considered this in our analyses. Our results show a lack of concordance between colour spectra and pollinator assemblages. Nevertheless, this work proves that colour determines plant-pollinator relationships in some degree. Thus, particular pollinator groups display preferences for certain bands of the colour spectrum. These preferences match those expected from the pollination syndromes theory. Future work on this issue should combine floral colour along with other floral traits, to assess the importance of the combination of the main floral features for determining pollinator attraction and behaviour together.

Introduced herbivores and the Allee effect in animal-pollinated plants

Vázquez,Diego P
Fonte: Ecología austral Publicador: Ecología austral
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2007 EN
Relevância na Pesquisa
36.29%
Interspecific interactions can be modulated by the community context in which they occur. In this paper I focus on plant-pollinator interactions and their modulation by introduced herbivores through changes in plant population density. I first develop a mathematical model that relates the population density of an animal-pollinated plant species with pollinator visitation frequency, pollination, reproduction and per capita growth rate. This model allows me to investigate how several pollination-related parameters -including relative abundance of the focal plant species, pollinator specialization, pollination quantity and quality and pollen limitation of reproduction- influence the relationship between per capita growth rate and population density. I then use this theoretical framework to discuss two case studies that have addressed the density-mediated effects of introduced herbivores on plant reproduction. This exercise allows me to point out several limitations of previous studies and to suggest avenues for future research.