scholarly journals Adaptive anonymity: Crypsis as an evolutionary trait of floral yeasts?

2016 ◽  
Author(s):  
Moritz Mittelbach ◽  
Andrey M. Yurkov ◽  
Dominik Begerow
Keyword(s):  
Strong Impact ◽  
Critical Survey ◽  
Flower Visitation ◽  
Foraging Preferences ◽  
Dead End ◽  
Allochthonous Species ◽  
Floral Visitors ◽  
Suitable Habitats ◽  
Plant Pollinator ◽  
Microbial Effects

AbstractNectar-dwelling yeast and bacteria are common inhabitants of flowers and evidently involved in pollination. The limited number of floral plant-pollinator models studied to date reveal inconsistent conclusions on microbial effects, but coincide with respect to high microbial specificity: while bacteria reduce visitation frequencies of pollinators, nectar-borne specialist yeasts (in contrast to allochthonous or transient species) impose none or even a beneficial effect on flower visitation. However, these findings are in conflict with the strong impact of these predominantly fermenting organisms on the nectar environment. In order to cope with the ultimate dependency of nectar-dwellers on repeated transportation by foragers as a result of early floral senescence, the modifications of nectar associated with specialist growth have been interpreted as adaptations that suit forager’s preferences. But, the development of foraging preferences to either axenic flowers or flowers colonized by specialist microorganisms would lead to a dead-end for nectar-dwellers, as the probability of inoculation into new suitable habitats would be reduced.Based on a critical survey of the available literature and an additional pollinator experiment where we find that the allochthonous species Cryptococcus victoriae negatively affects attraction and rewarding of floral visitors, while the specialist yeast Metschnikowia reukaufii does not, we propose the hypothesis that nectar-borne yeasts may have evolved to blend into their environment avoiding detection by pollinators, following the ecological concept of crypsis. Although, neither chemical nor olfactory crypsis has been reported for nectar-borne microorganisms, the attention to this mechanism in yeast dispersal needs to be directed in future studies.

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 Selective pollination by fungus gnats potentially functions as an alternative reproductive isolation among five Arisaema species

2020 ◽  
Author(s):  
Tetsuya K Matsumoto ◽  
Muneto Hirobe ◽  
Masahiro Sueyoshi ◽  
Yuko Miyazaki
Keyword(s):  
Reproductive Isolation ◽  
Altitudinal Gradient ◽  
Flowering Phenology ◽  
Altitudinal Distribution ◽  
Interspecific Differences ◽  
Flower Visitation ◽  
Fungus Gnats ◽  
Floral Visitor ◽  
Floral Visitors ◽  
Experimental Plots

Abstract Background and Aims Interspecific difference in pollinators (pollinator isolation) is important for reproductive isolation in flowering plants. Species-specific pollination by fungus gnats has been discovered in several plant taxa, suggesting that they can contribute to reproductive isolation. Nevertheless, their contribution has not been studied in detail, partly because they are too small for field observations during flower visitation. To quantify their flower visitation, we used the genus Arisaema (Araceae) because the pitcher-like spathe of Arisaema can trap all floral visitors. Methods We evaluated floral visitor assemblage in an altitudinal gradient including five Arisaema species. We also examined interspecific differences in altitudinal distribution (geographic isolation) and flowering phenology (phenological isolation). To exclude the effect of interspecific differences in altitudinal distribution on floral visitor assemblage, we established 10 experimental plots including the five Arisaema species on high- and low-altitude areas and collected floral visitors. We also collected floral visitors in three additional sites. Finally, we estimated the strength and contribution of these three reproductive barriers using the unified formula for reproductive isolation. Key Results Each Arisaema species selectively attracted different fungus gnats in the altitudinal gradient, experimental plots, and additional sites. Altitudinal distribution and flowering phenology differed among the five Arisaema species, whereas the strength of geographic and phenological isolations were distinctly weaker than those in pollinator isolation. Nevertheless, the absolute contribution of pollinator isolation to total reproductive isolation was weaker than geographic and phenological isolations, because pollinator isolation functions after the two early-acting barriers in plant life history. Conclusions Our results suggest that selective pollination by fungus gnats potentially contributes to reproductive isolation. Since geographic and phenological isolations can be disrupted by habitat disturbance and interannual climate change, the strong and stable pollinator isolation might compensate for the weakened early-acting barriers as an alternative reproductive isolation among the five Arisaema species.

scholarly journals Potential Pitfalls in Membrane Fouling Evaluation: Merits of Data Representation as Resistance Instead of Flux Decline in Membrane Filtration

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 460
Author(s):  
Bastiaan Blankert ◽  
Bart Van der Bruggen ◽  
Amy E. Childress ◽  
Noreddine Ghaffour ◽  
Johannes S. Vrouwenvelder
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Data Representation ◽  
Strong Impact ◽  
Experimental Conditions ◽  
Permeable Membrane ◽  
Dead End ◽  
Flux Decline ◽  
The Difference ◽  
Filtration Flux

The manner in which membrane-fouling experiments are conducted and how fouling performance data are represented have a strong impact on both how the data are interpreted and on the conclusions that may be drawn. We provide a couple of examples to prove that it is possible to obtain misleading conclusions from commonly used representations of fouling data. Although the illustrative example revolves around dead-end ultrafiltration, the underlying principles are applicable to a wider range of membrane processes. When choosing the experimental conditions and how to represent fouling data, there are three main factors that should be considered: (I) the foulant mass is principally related to the filtered volume; (II) the filtration flux can exacerbate fouling effects (e.g., concentration polarization and cake compression); and (III) the practice of normalization, as in dividing by an initial value, disregards the difference in driving force and divides the fouling effect by different numbers. Thus, a bias may occur that favors the experimental condition with the lower filtration flux and the less-permeable membrane. It is recommended to: (I) avoid relative fouling performance indicators, such as relative flux decline (J/J0); (II) use resistance vs. specific volume; and (III) use flux-controlled experiments for fouling performance evaluation.

scholarly journals Linking pollinator efficiency to patterns of pollen limitation: small bees exploit the plant–pollinator mutualism

2018 ◽  
Vol 285 (1880) ◽  
pp. 20180635 ◽  
Author(s):  
Matthew H. Koski ◽  
Jennifer L. Ison ◽  
Ashley Padilla ◽  
Angela Q. Pham ◽  
Laura F. Galloway
Keyword(s):  
Pollen Limitation ◽  
Pollen Deposition ◽  
Pollinator Efficiency ◽  
Flower Visitation ◽  
Female Phase ◽  
Male Phase ◽  
Single Flower ◽  
Floral Visitation ◽  
Low Efficiency ◽  
Plant Pollinator

Seemingly mutualistic relationships can be exploited, in some cases reducing fitness of the exploited species. In plants, the insufficient receipt of pollen limits reproduction. While infrequent pollination commonly underlies pollen limitation (PL), frequent interactions with low-efficiency, exploitative pollinators may also cause PL. In the widespread protandrous herb Campanula americana , visitation by three pollinators explained 63% of the variation in PL among populations spanning the range. Bumblebees and the medium-sized Megachile campanulae enhanced reproductive success, but small solitary bees exacerbated PL. To dissect mechanisms behind these relationships, we scored sex-specific floral visitation, and the contributions of each pollinator to plant fitness using single flower visits. Small bees and M. campanulae overvisited male-phase flowers, but bumblebees frequently visited female-phase flowers. Fewer bumblebee visits were required to saturate seed set compared to other bees. Scaling pollinator efficiency metrics to populations, small bees deplete large amounts of pollen due to highly male-biased flower visitation and infrequent pollen deposition. Thus, small bees reduce plant reproduction by limiting pollen available for transfer by efficient pollinators, and appear to exploit the plant–pollinator mutualism, acting as functional parasites to C. americana . It is therefore unlikely that small bees will compensate for reproductive failure in C. americana when bumblebees are scarce.

scholarly journals High species richness of native pollinators in Brazilian tomato crops

2016 ◽  
Vol 77 (3) ◽  
pp. 506-513 ◽  
Author(s):  
C. M. Silva-Neto ◽  
L. L. Bergamini ◽  
M. A. S. Elias ◽  
G. L. Moreira ◽  
J. M. Morais ◽  
...  
Keyword(s):  
Pollen Grains ◽  
Crop Productivity ◽  
Fruit Production ◽  
Natural Ecosystems ◽  
Pollinator Visitation ◽  
Central Brazil ◽  
High Species Richness ◽  
Floral Visitors ◽  
Plant Pollinator ◽  
Effective Pollinators

Abstract Pollinators provide an essential service to natural ecosystems and agriculture. In tomatoes flowers, anthers are poricidal, pollen may drop from their pore when flowers are shaken by the wind. However, bees that vibrate these anthers increase pollen load on the stigma and in fruit production. The present study aimed to identify the pollinator richness of tomato flowers and investigate their morphological and functional traits related to the plant-pollinator interaction in plantations of Central Brazil. The time of anthesis, flower duration, and the number and viability of pollen grains and ovules were recorded. Floral visitors were observed and collected. Flower buds opened around 6h30 and closed around 18h00. They reopened on the following day at the same time in the morning, lasting on average 48 hours. The highest pollen availability occurred during the first hours of anthesis. Afterwards, the number of pollen grains declined, especially between 10h00 to 12h00, which is consistent with the pollinator visitation pattern. Forty bee species were found in the tomato fields, 30 of which were considered pollinators. We found that during the flowering period, plants offered an enormous amount of pollen to their visitors. These may explain the high richness and amount of bees that visit the tomato flowers in the study areas. The period of pollen availability and depletion throughout the day overlapped with the bees foraging period, suggesting that bees are highly effective in removing pollen grains from anthers. Many of these grains probably land on the stigma of the same flower, leading to self-pollination and subsequent fruit development. Native bees (Exomalopsis spp.) are effective pollinators of tomato flowers and are likely to contribute to increasing crop productivity. On the other hand, here tomato flowers offer large amounts of pollen resource to a high richness and amount of bees, showing a strong plant-pollinator interaction in the study agroecosystem.

scholarly journals Elevated CO2 Impacts on Plant–Pollinator Interactions: A Systematic Review and Free Air Carbon Enrichment Field Study

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 512
Author(s):  
Liam M. Crowley ◽  
Jonathan P. Sadler ◽  
Jeremy Pritchard ◽  
Scott A. L. Hayward
Keyword(s):  
Systematic Review ◽  
Elevated Co2 ◽  
Flowering Phenology ◽  
Flowering Duration ◽  
Flower Visitation ◽  
Significant Difference ◽  
Abundance And Diversity ◽  
Syrphid Flies ◽  
The Impact ◽  
Plant Pollinator

The impact of elevated CO2 (eCO2) on plant–pollinator interactions is poorly understood. This study provides the first systematic review of this topic and identifies important knowledge gaps. In addition, we present field data assessing the impact of eCO2 (150 ppm above ambient) on bluebell (Hyacinthoides non-scripta)–pollinator interactions within a mature, deciduous woodland system. Since 1956, only 71 primary papers have investigated eCO2 effects on flowering time, floral traits and pollination, with a mere 3 studies measuring the impact on pollination interactions. Our field experiment documented flowering phenology, flower visitation and seed production, as well as the abundance and phenology of dominant insect pollinators. We show that first and mid-point flowering occurred 6 days earlier under eCO2, but with no change in flowering duration. Syrphid flies and bumble bees were the dominant flower visitors, with peak activity recorded during mid- and late-flowering periods. Whilst no significant difference was recorded in total visitation or seed set between eCO2 and ambient treatments, there were clear patterns of earlier flowering under eCO2 accompanied by lower pollinator activity during this period. This has implications for potential loss of synchrony in pollination systems under future climate scenarios, with associated long-term impacts on abundance and diversity.

scholarly journals Pollen on stigmas as proxies of pollinator competition and facilitation: complexities, caveats and future directions

2020 ◽  
Vol 125 (7) ◽  
pp. 1003-1012 ◽  
Author(s):  
Tia-Lynn Ashman ◽  
Conchita Alonso ◽  
Victor Parra-Tabla ◽  
Gerardo Arceo-Gómez
Keyword(s):  
Pollen Transfer ◽  
Future Directions ◽  
Indirect Measure ◽  
Heterospecific Pollen ◽  
Complex Processes ◽  
Flower Visitation ◽  
Fitness Consequences ◽  
Functional Aspects ◽  
Broad Variety ◽  
Plant Pollinator

Abstract Background Pollen transfer via animals is necessary for reproduction by ~80 % of flowering plants, and most of these plants live in multispecies communities where they can share pollinators. While diffuse plant–pollinator interactions are increasingly recognized as the rule rather than the exception, their fitness consequences cannot be deduced from flower visitation alone, so other proxies, functionally closer to seed production and amenable for use in a broad variety of diverse communities, are necessary. Scope We conceptually summarize how the study of pollen on stigmas of spent flowers can reflect key drivers and functional aspects of the plant–pollinator interaction (e.g. competition, facilitation or commensalism). We critically evaluate how variable visitation rates and other factors (pollinator pool and floral avoidance) can give rise to different relationships between heterospecific pollen and (1) conspecific pollen on the stigma and (2) conspecific tubes/grain in the style, revealing the complexity of potential interpretations. We advise on best practices for using these proxies, noting the assumptions and caveats involved in their use, and explicate what additional data are required to verify interpretation of given patterns. Conclusions We conclude that characterizing pollen on stigmas of spent flowers provides an attainable indirect measure of pollination interactions, but given the complex processes of pollen transfer that generate patterns of conspecific–heterospecific pollen on stigmas these cannot alone determine whether competition or facilitation are the underlying drivers. Thus, functional tests are also needed to validate these hypotheses.

scholarly journals EVALUATION OF FLORAL CHARACTERISTICS OF MELON HYBRIDS (Cucumis melo L.) IN POLLINATOR ATTRACTIVENESS

2016 ◽  
Vol 38 (2) ◽  
Author(s):  
LÚCIA HELENA PIEDADE KIILL ◽  
EDSÂNGELA DE ARAÚJO FEITOZA ◽  
KÁTIA MARIA MEDEIROS DE SIQUEIRA ◽  
MÁRCIA DE FÁTIMA RIBEIRO ◽  
EVA MÔNICA SARMENTO DA SILVA
Keyword(s):  
Floral Morphology ◽  
Nectar Production ◽  
Floral Visitors ◽  
Male Flowers ◽  
Study Sites ◽  
Yellow Type ◽  
Cucumis Melo L ◽  
Simultaneous Flowering ◽  
Plant Pollinator ◽  
Corolla Diameter

ABSTRACT Floral morphology and biology are important characteristics for plant-pollinator interactions and may influence the behavior of these agents. This study aimed to determine which floral attributes of different melon hybrids influence this interaction and, consequently, their attractiveness in simultaneous crops. The study was conducted in the region of Petrolina, State of Pernambuco (PE)/Juazeiro, State of Bahia (BA) and Mossoró, State of Rio Grande do Norte (RN), in areas with the following melon hybrids: Yellow type, Piel de Sapo, Cantaloupe and Galia. For studies on floral morphology and biology, hermaphrodites and male flowers of each hybrid were analyzed for their size and nectar chamber size, pollen and nectar production, anthesis time and flower lifespan. Floral visitors were observed simultaneously in hybrids of three types of melon, from 5:00 a.m. to 6:00 p.m., in the two study sites. Evaluations of the corolla diameter and flower height indicated that the hermaphrodite flowers were larger in size than male flowers in all types of melon investigated, in both study sites. As for nectar chamber, male flowers are larger in width, but smaller in height, compared to hermaphrodite flowers. Regarding the volume of nectar, differences were found between floral types for the hybrids evaluated, in the two study sites; the hermaphrodite flowers produced 2-7 times more nectar than male flowers in all studied hybrids. Observations of visits of Apis mellifera to areas with simultaneous flowering of the three types of melon demonstrated differences in the frequency of visits between hybrids, floral type and foraged resource. Flowers of the hybrids Piel de Sapo and Cantaloupe exhibited larger corolla diameter, larger dimensions of the nectar chamber and greater supply of resources for foraging, which could explain the higher number of visits of bees to their flowers in the sites studied.

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