scholarly journals Flower morphological differentiation and plant-pollinator interactions among sympatric Aframomum species (Zingiberaceae) with floral trumpet type in the tropical African rainforest

2021 ◽  
Vol 154 (3) ◽  
pp. 447-457
Author(s):  
Elie Chrisnel Nzigou Doubindou ◽  
Alexandra C. Ley
Keyword(s):  
Competitive Exclusion ◽  
Morphological Differentiation ◽  
Species Boundaries ◽  
Morphological Parameters ◽  
Geographic Isolation ◽  
Pollinator Attraction ◽  
Nectar Volume ◽  
The Past ◽  
Floral Diversity ◽  
Plant Pollinator

Background and aims – Diversification in plant-pollinator interactions based on floral diversity is potentially a mechanism of coexistence in angiosperms. However, besides high floral diversity, some genera seemingly exhibit the same floral type in many of their species. This contradicts some expectations of competitive exclusion. We thus tested on a finer flower morphological scale whether five sympatric Aframomum species (61 spp., Zingiberaceae) in southeastern Gabon exhibiting the same general floral type (trumpet) were differentiated, and whether this resulted in different “pollinator niches”.Material and methods – We carried out a detailed survey measuring 18 flower morphological parameters as well as nectar volume (μl) and sugar concentration (% Brix) on five flowers per species and locality. Furthermore, we observed inflorescence phenology and pollinator activity from 8 am to 4 pm for 12 to 50 hours per species and conducted pollinator exclusion experiments.Key results – This study proves fine-scale flower morphological and resource differentiation within the trumpet floral type. Pollination-relevant parts of the flowers, however, remain constant across species. Our pollinator observations reveal the same broad bee pollinator spectrum for all observed simultaneously flowering sympatric species.Conclusion – As we could not detect a pollinator-based differentiation in the studied sympatric Aframomum species we assume that species boundaries developed randomly by genetic drift during geographic isolation in the past. The trumpet floral type and its pollinator guild, however, were maintained due to similar selection pressures in comparable habitats during isolation and are potentially an advantage for increased pollinator attraction through co-flowering.

The Floral Microbiome: Plant, Pollinator, and Microbial Perspectives

2020 ◽  
Vol 51 (1) ◽  
pp. 363-386 ◽  
Author(s):  
Rachel L. Vannette
Keyword(s):  
Multiple Scales ◽  
Ecological Processes ◽  
Pollinator Attraction ◽  
Plant Variation ◽  
Floral Visitors ◽  
Floral Phenotype ◽  
Bacteria And Fungi ◽  
Plant Pollinator ◽  
Microbial Effects

Flowers at times host abundant and specialized communities of bacteria and fungi that influence floral phenotypes and interactions with pollinators. Ecological processes drive variation in microbial abundance and composition at multiple scales, including among plant species, among flower tissues, and among flowers on the same plant. Variation in microbial effects on floral phenotype suggests that microbial metabolites could cue the presence or quality of rewards for pollinators, but most plants are unlikely to rely on microbes for pollinator attraction or reproduction. From a microbial perspective, flowers offer opportunities to disperse between habitats, but microbial species differ in requirements for and benefits received from such dispersal. The extent to which floral microbes shape the evolution of floral traits, influence fitness of floral visitors, and respond to anthropogenic change is unclear. A deeper understanding of these phenomena could illuminate the ecological and evolutionary importance of floral microbiomes and their role in the conservation of plant–pollinator interactions.

scholarly journals Chemical signal is in the blend: bases of plant-pollinator encounter in a highly specialized interaction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Magali Proffit ◽  
Benoit Lapeyre ◽  
Bruno Buatois ◽  
Xiaoxia Deng ◽  
Pierre Arnal ◽  
...  
Keyword(s):  
Pollinator Attraction ◽  
Plant Insect Interactions ◽  
Electrophysiological Tests ◽  
Plant Recognition ◽  
Pollination Mutualism ◽  
Volatile Organic ◽  
Small Change ◽  
Insect Interactions ◽  
Behavioural Tests ◽  
Plant Pollinator

Abstract In several highly specialized plant-insect interactions, scent-mediated specificity of pollinator attraction is directed by the emission and detection of volatile organic compounds (VOCs). Although some plants engaged in such interactions emit singular compounds, others emit mixtures of VOCs commonly emitted by plants. We investigated the chemical ecological bases of host plant recognition in the nursery pollination mutualism between the dioecious Ficus carica and its specific pollinator Blastophaga psenes. Using Y-tube olfactometer tests, we show that B. psenes females are attracted by VOCs of receptive figs of both sexes and do not exhibit preference for VOCs of either male or female figs. Electrophysiological tests and chemical analysis revealed that of all the VOCs emitted by receptive figs, only five were found to be active on female antennae. Behavioural tests show that, in contrast to VOCs presented alone, only a blend with a particular proportion of four of these VOCs is as attractive as the odour of receptive figs, and that if there is a very small change in this blend proportion, the pollinator is no longer attracted. This study revealed that in highly specialized mutualistic interactions specificity could be mediated by a particular blend of common compounds emitted by plants.

The paradox of the “paradox of the plankton”

2013 ◽  
Vol 71 (2) ◽  
pp. 236-240 ◽  
Author(s):  
Nicholas R. Record ◽  
Andrew J. Pershing ◽  
Frédéric Maps
Keyword(s):  
Environmental Variables ◽  
Competitive Exclusion ◽  
Type Systems ◽  
Community Level ◽  
Limited Resources ◽  
Additional Parameter ◽  
Ecosystem Models ◽  
The Past ◽  
Systems Of Differential Equations ◽  
Ocean Ecosystem

Abstract Record, N. R., Pershing, A. J., and Maps, F. 2014. The paradox of the “paradox of the plankton”. – ICES Journal of Marine Science, 71: 236–240. One of the central orienting questions in biodiversity theory and ecology is the “paradox of the plankton”, which asks how it is possible for many species to coexist on limited resources given the tendency for competition to exclude species. Over the past five decades, ecologists have offered dozens of solutions to the paradox, invoking game theory, chaos, stochastics, and many other concepts. Despite the plentitude of solutions to the paradox, ecologists continue to offer up novel solutions. Ocean modellers are now faced with the opposite paradox: given the overabundance and the diversity of solutions to the paradox, what is the appropriate way to build coexistence into ecosystem models? Ocean ecosystem models have a very standardized form—nutrient–phytoplankton–zooplankton (NPZ)-type systems of differential equations—where competitive exclusion is a common model behaviour. We suggest approaching the problem from the perspective of community-level patterns. We offer a prototype for building coexistence into NPZ models. The model allows for diverse assemblages of phytoplankton or zooplankton groups to persist and produces accurate community-level patterns. The approach is simple, adding only one additional parameter, and allows us to test the effects of trait distributions and environmental variables on diversity.

scholarly journals Does the Rarity of a Flower’s Scent Phenotype in a Deceptive Orchid Explain Its Pollination Success?

2020 ◽  
Vol 11 ◽  
Author(s):  
Herbert Braunschmid ◽  
Stefan Dötterl
Keyword(s):  
Floral Scent ◽  
Dynamic Headspace ◽  
Pollinator Attraction ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Pollination Success ◽  
Cypripedium Calceolus ◽  
Negative Frequency Dependent Selection ◽  
Plant Pollinator ◽  
Two Populations

Floral scent, a key mediator in plant–pollinator interactions, varies not only among plant species, but also within species. In deceptive plants, it is assumed that variation in floral scents and other traits involved in pollinator attraction is maintained by negative frequency-dependent selection, i.e., rare phenotypes are more attractive to pollinators and hence, have a higher fitness than common phenotypes. So far, it is unknown whether the rarity of multivariate and/or continuous floral scent traits influences the pollination success of flowers. Here, we tested in the deceptive orchid Cypripedium calceolus, whether flowers with rarer scent bouquets within a population have a higher chance to getting pollinated than flowers with more common scents. We collected the scent of more than 100 flowers in two populations by dynamic headspace and analyzed the samples by gas chromatography coupled to mass spectrometry (GC/MS). From the same flowers we also recorded whether they set a fruit or not. We introduced rarity measures of uni- and multivariate floral scent traits for single flowers, which allowed us to finally test for frequency-dependent pollination, a prerequisite for negative frequency-dependent selection. Our results do not show rarity has an effect on the likelihood to set fruits in neither of the two populations and in none of the scent characteristics analyzed. Hence, there is no evidence of negative frequency-dependent pollination mediated by the floral scent of C. calceolus. We discuss that our approach to determine rarity of a scent is applicable to any univariate or multivariate (semi)quantitative trait.

scholarly journals Morphological characterization of sympatric and allopatric populations of Petunia axillaris and P. exserta (Solanaceae)

2020 ◽  
Vol 192 (3) ◽  
pp. 550-567 ◽  
Author(s):  
Marcelo Costa Teixeira ◽  
Caroline Turchetto ◽  
Renan Maestri ◽  
Loreta B Freitas
Keyword(s):  
Morphological Characterization ◽  
Floral Display ◽  
Pollinator Attraction ◽  
Contact Zones ◽  
Low Genetic Diversity ◽  
Floral Diversity ◽  
Corolla Colour ◽  
Morphometric Analyses ◽  
Hybrid Classes ◽  
Petunia Axillaris

Abstract Floral morphological traits are frequently used to identify species, including those that are closely related and show low genetic diversity, and floral shape and colour are known to play an important role in diversification and species isolation. Floral morphology in Petunia (Solanaceae) is considered a driver of diversification because of its association with pollinators. Here, flower morphology was characterized through morphometric analyses and floral pigments. Our main aim was to determine corolla shape in populations of Petunia axillaris and P. exserta and their natural hybrids and how floral display, size and colour are involved in pollinator attraction. In addition, we investigated floral pigments in P. exserta and different hybrid classes. The results from morphometric analyses revealed that each species has a specific floral shape, independent of the collection site. By contrast, in two contact zones, a mosaic of floral phenotypes was observed with some hybrid classes based on corolla colour being placed close to P. exserta. The results suggest that several generations of hybrids or backcrossing could have given rise to this floral diversity in contact zones.

scholarly journals Microbial metabolites elicit distinct olfactory and gustatory preferences in bumblebees

2019 ◽  
Vol 15 (7) ◽  
pp. 20190132 ◽  
Author(s):  
Robert N. Schaeffer ◽  
Caitlin C. Rering ◽  
Isabelle Maalouf ◽  
John J. Beck ◽  
Rachel L. Vannette
Keyword(s):  
Preference Test ◽  
Microbial Metabolites ◽  
Pollinator Attraction ◽  
Olfactory Neurons ◽  
Volatile Metabolites ◽  
Volatile Organic ◽  
Microbial Volatile Organic Compounds ◽  
Choice Feeding ◽  
Plant Pollinator

Animals such as bumblebees use chemosensory cues to both locate and evaluate essential resources. Increasingly, it is recognized that microbes can alter the quality of foraged resources and produce metabolites that may act as foraging cues. The distinct nature of these chemosensory cues however and their use in animal foraging remain poorly understood. Here, we test the hypothesis that species of nectar-inhabiting microbes differentially influence pollinator attraction and feeding via microbial metabolites produced in nectar. We first examined the electrophysiological potential for bumblebee ( Bombus impatiens ) antennal olfactory neurons to respond to microbial volatile organic compounds (mVOCs), followed by an olfactory preference test. We also assessed gustatory preferences for microbial-altered nectar through both no-choice and choice feeding assays. Antennal olfactory neurons responded to some mVOCs, and bees preferred nectar solutions inoculated with the bacterium Asaia astilbes over the yeast Metschnikowia reukaufii based on volatiles alone. However, B. impatiens foragers consumed significantly more Metschnikowia -inoculated nectar, suggesting distinct roles for mVOCs and non-volatile metabolites in mediating both attraction and feeding decisions. Collectively, our results suggest that microbial metabolites have significant potential to shape interspecific, plant–pollinator signalling, with consequences for forager learning, economics and floral host reproduction.

scholarly journals Nectar as manipulator: how nectar traits influence changes in pollinator groups of Aechmea vanhoutteana, a bromeliad from the Brazilian Atlantic Forest

2019 ◽  
Vol 192 (4) ◽  
pp. 803-815
Author(s):  
Vivian Zambon ◽  
Kayna Agostini ◽  
Massimo Nepi ◽  
Mônica Lanzoni Rossi ◽  
Adriana Pinheiro Martinelli ◽  
...  
Keyword(s):  
Reproductive Strategy ◽  
Spatial And Temporal Variability ◽  
Ecological Interactions ◽  
Nectar Production ◽  
Generalist Species ◽  
Nectar Volume ◽  
Plant Resource ◽  
Floral Resource ◽  
Plant Pollinator ◽  
Production Dynamics

Abstract Nectar is an important floral resource in the establishment of plant-pollinator interactions. Recent studies have shown that nectariferous tissues are independent of the ABC model of floral development and that ecological interactions can modify their expression. In this sense, it would be interesting to study generalist species in relation to nectar production and nectary morpho-anatomy to verify the strategies used to attract different pollinator groups. We recorded nectar production dynamics in Aechmea vanhoutteana (Bromeliaceae) from a morpho-functional and ultrastructural perspective. We observed different species of hummingbirds, bees and butterflies visiting flowers of A.vanhoutteana, and their frequency varied throughout floral anthesis. The nectar volume and quantity of sugar also varied significantly during anthesis, and this spatial and temporal variability seems to be related to an increase in bee visits, representing an important aspect of the reproductive strategy of this species, since bees can fly longer distances than the observed hummingbirds (although both have territorial behaviours). Thus, it can be suggested that anatomical and physiological nectar traits may be related to pollen flow, an important aspect of the reproductive strategy of A. vanhoutteana, suggesting plant resource allocation for optimizing reproduction through nectar production.

Taxonomy of Sarga, Sorghum and Vacoparis (Poaceae: Andropogoneae)

2003 ◽  
Vol 16 (3) ◽  
pp. 279 ◽  
Author(s):  
Russell E. Spangler
Keyword(s):  
Type Species ◽  
New Genus ◽  
Species Boundaries ◽  
Morphological Evidence ◽  
Species Limits ◽  
The Past ◽  
Distinct Genus ◽  
Variable Species ◽  
Rank Constraints ◽  
Name Changes

Sorghum taxa are evaluated in light of recent molecular and morphological evidence. The data suggest that three distinct lineages exist, but relationships among these lineages are unresolved. Each lineage is recognised here as a distinct genus in the context of overall variation in tribe Andropogoneae. The type species for the name Sorghum is S. bicolor, the cultivar. S. halepense and S. nitidum are also retained in Sorghum. The name Sarga is resurrected to encompass the set of species formerly making up the bulk of subgenera Parasorghum and Stiposorghum. A new genus, Vacoparis, is defined to include the cytologically and morphologically distinct Australasian taxa, V. macrospermum and V. laxiflorum. The taxonomy proposed is contrasted with a rankless alternative to illustrate the smaller number of name changes that can be accomplished when rank constraints are not enforced. Uncertain relationships among the three lineages as well as among a large number of taxa comprising subtribe Saccharinae exemplifies the difficulties in assigning ranks to taxa that may have future dramatic name changes with new data. As discussions progress concerning the validity and utility of rankless classifications, concrete examples, such as the revision presented here, can provide insights into specific cases where strengths and weaknesses can be evaluated. Species boundaries in Sarga are different from those formerly defined. Continuous variation across specimens in characters used to distinguish taxa in the past led to the decision to broaden species limits so that fewer and morphologically variable species are recognised.

Variation in floral morphology and ploidy among populations of Collinsia parviflora and Collinsia grandiflora

Botany ◽  
2011 ◽  
Vol 89 (1) ◽  
pp. 19-33 ◽  
Author(s):  
Nicole D. Tunbridge ◽  
Chris Sears ◽  
Elizabeth Elle
Keyword(s):  
Floral Morphology ◽  
Full Range ◽  
Morphological Differentiation ◽  
Population Variation ◽  
Flower Size ◽  
Species Boundaries ◽  
Chromosome Counts ◽  
Geographically Dispersed ◽  
Selection For ◽  
Floral Form

Variation in floral form complicates species identification, and when variation in ploidy also occurs, taxonomic designations are significantly compromised. We studied morphological and ploidy variation in sister species Collinsia parviflora Lindl. (small-flowered form) and Collinsia grandiflora Douglas ex Lindl. (large-flowered form), sampling from California, where the species were previously described as diploids, to British Columbia, where morphologically variable populations were more recently designated tetraploid. We found continuous among-population variation in flower size and shape throughout our sampled range. Ploidy variation, estimated using a combination of chromosome counts and flow cytometry, was not associated with flower size. Diploid populations were rare, and both large-flowered and small-flowered diploids were identified. Tetraploid populations were common, geographically dispersed, and exhibited the full range of flower sizes. A few populations of small-flowered plants were putative hexaploids. When large- and small-flowered forms co-occurred, they were diploid and tetraploid, respectively, suggesting morphological differentiation from selection for reproductive isolation between co-occurring plants of different ploidy. Although diploid C. parviflora (small-flowered) and C. grandiflora (large-flowered) occur, the majority of our sample consisted of morphologically variable tetraploids, suggesting that the use of flower size to delineate species is inappropriate. Further research is needed to ensure a true description of species boundaries in this group.

scholarly journals Overcome Competitive Exclusion in Ecosystems

2018 ◽  
Author(s):  
Xin Wang ◽  
Yang-Yu Liu
Keyword(s):  
Steady State ◽  
Competitive Exclusion ◽  
Fundamental Problem ◽  
Exclusion Principle ◽  
Competitive Exclusion Principle ◽  
The Past ◽  
Number Of Species ◽  
Coexisting Species ◽  
Consumer Resource

AbstractExplaining biodiversity in nature is a fundamental problem in ecology. One great challenge is embodied in the so-called competitive exclusion principle1-4: the number of species in steady coexistence cannot exceed the number of resources4-7. In the past five decades, various mechanisms have been proposed to overcome the limit on diversity set by the competitive exclusion principle8-25. Yet, none of the existing mechanisms can generically overcome competitive exclusion at steady state4,26. Here we show that by forming chasing triplets in the predation process among the consumers and resources, the number of coexisting species of consumers can exceed that of resources at steady state, naturally breaking the competitive exclusion principle. Our model can be broadly applicable to explain the biodiversity of many consumer-resource ecosystems and deepen our understanding of biodiversity in nature.

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