Pollinator Visitation, Floral Display, and Nectar Production of the Sexual Morphs of a Gynodioecious Shrub

Oikos ◽  
1992 ◽  
Vol 63 (2) ◽  
pp. 161 ◽  
Author(s):  
Lynda F. Delph ◽  
Curtis M. Lively
Keyword(s):  
Floral Display ◽  
Nectar Production ◽  
Pollinator Visitation

scholarly journals High selfing capability and low pollinator visitation in the epiphyte Pitcairnia heterophylla (Bromeliaceae) at a Costa Rican cloud forest

2016 ◽  
Author(s):  
Luis D. Ríos ◽  
Alfredo Cascante-Marín
Keyword(s):  
Cloud Forest ◽  
Video Recording ◽  
Floral Traits ◽  
Nectar Production ◽  
Pollinator Visitation ◽  
Visitation Rate ◽  
Pollinator Visitation Rate ◽  
Hand Pollination ◽  
Pollination Systems ◽  
Epiphytic Bromeliads

AbstractMost epiphytic bromeliads exhibit specialized pollination systems likely to promote out-crossing but, at the same time, possess floral traits that promote autonomous selfing. Adaptations that promote selfing in flowering plants with specialized pollination systems have been considered as a mechanism for reproductive assurance. In this paper, we analyzed the breeding system and pollinator visitation rate of the hummingbird-pollinated bromeliad Pitcairnia heterophylla in order to see if they fit such trend. We performed hand pollination experiments, video recording of floral visitors, and recorded floral traits in order to describe the reproductive and pollination system of the studied species in a cloud forest in Costa Rica. Results from the pollination treatments indicated that P. heterophylla is self-compatible (SCIf = 0.77), capable of autonomous pollination (AFIf = 0.78), and non-agamospermous (AGf = 0.01). Floral traits, such as scentless red flowers, with tubular corolla and nectar production, suggested ornithophily which was confirmed by the video recording of Lampornis calolaemus (Trochilidae) visiting flowers. However, the visitation rate was low (0.6 visits day-1 per plant) based on 918 hours of video recording using trail cameras. We suggest that the high selfing capability of the studied population of P. heterophylla might be related to the low pollinator visitation rate. If low pollinator visitation is common among hummingbird-pollinated and epiphytic bromeliads, then selfing could be a widespread mechanism to enhance their reproductive success.

scholarly journals Sexual dimorphism in the dioecious monocot Lomandra leucocephala ssp. robusta and its potential ecosystem and conservation significance

2020 ◽  
Vol 68 (4) ◽  
pp. 275
Author(s):  
Jenna T. Draper ◽  
John G. Conran ◽  
Nicholas Crouch ◽  
Philip Weinstein ◽  
Bradley S. Simpson
Keyword(s):  
Sand Dunes ◽  
Species Conservation ◽  
Gas Chromatography Mass Spectrometry ◽  
Floral Display ◽  
Pollination Services ◽  
Pollinator Visitation ◽  
Glucose Content ◽  
Sexual Dimorphisms ◽  
Flowering Periods ◽  
Generalist Pollination

Dioecious plants constitute 7% of all angiosperm species, yet they occur in many habitat types, partially through the deployment of sexual dimorphisms that assist in reproduction. In the present work, the dioecious monocot Lomandra leucocephala ssp. robusta (Asparagaceae: Lomandroideae) was studied to understand how sexual dimorphisms can assist species conservation and inform us of a species’ potential significance in an ecosystem. Floral display was sexually dimorphic, as male inflorescences were displayed more prominently and more conspicuously in UV range. Male nectar analysed by thin-layer chromatography contained a higher glucose content than female nectar. However, both sexes contained hexose-rich nectar, a common indicator of generalist pollination, which was supported by observations of floral visitors. Floral extract comparison conducted via gas chromatography-mass spectrometry showed that male extracts contained more compounds that potentially convey greater resistance to biotic and abiotic threats. Chemical comparison of leaves by high performance liquid chromatography with peak area ratio analysis revealed this technique could be used as a tool for gender identification of individuals during non-flowering periods. Due to the generalist pollination mechanisms of L. leucocephala ssp. robusta, may have an important role in the conservation and support of local insect populations. The presence of chemical biotic and abiotic resistance may also make L. leucocephala ssp. robusta a significant contributor to the ongoing stabilisation of the sand dunes. Conservation efforts required for L. leucocephala ssp. robusta are likely to be minimal, as pollination services are provided by a diversity of pollinating taxa, including introduced species, which will be abundant regardless of variable flowering periods. Further observational study of L. leucocephala ssp. robusta pollinators and differences in pollinator visitation behaviours between sexes is recommended to better understand efficient pollination for the species, and potentially reveal a greater extent of ecosystem benefit for this species.

Flower-visitors, nectar production, and inflorescence size of Asclepias syriaca

1979 ◽  
Vol 57 (12) ◽  
pp. 1380-1388 ◽  
Author(s):  
M. F. Willson ◽  
R. I. Bertin
Keyword(s):  
Honey Bees ◽  
Native Species ◽  
Flowering Phenology ◽  
Spatial And Temporal Variation ◽  
Floral Display ◽  
Asclepias Syriaca ◽  
Nectar Production ◽  
Inflorescence Size ◽  
Visitation Rates ◽  
The Common

Spatial and temporal variation in insect visitation rates are analyzed with respect to nectar production and inflorescence size of Asclepias syriaca L., the common milkweed. Nectar sugar production peaked in the afternoon and evening but this trend was not paralleled by visitations of native insects (either vectors or thieves). The main pollinia vectors were noctuid moths at night and honey bees (Apis mellifera) in the afternoon. Vector visitation rates were highest at the beginning (native species) or middle (total vectors) of the blooming season, declining markedly toward the end, probably as a result of decreasing frequencies of A. syriaca flowers. Large inflorescences attracted more vectors and more thieves and a higher proportion of all visits were made by vectors but the species composition of visitors did not usually change with inflorescence size. We discuss the possibility that honey bees may provide major 'new' selection pressures on floral display, nectar production patterns, and flowering phenology in the common milkweed.

scholarly journals Pollination intensity and paternity in flowering plants

2019 ◽  
Vol 125 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Dorothy A Christopher ◽  
Randall J Mitchell ◽  
Jeffrey D Karron
Keyword(s):  
Reproductive Success ◽  
Pollen Limitation ◽  
Ecological Factors ◽  
Plant Evolution ◽  
Male Reproductive Success ◽  
Floral Display ◽  
Heritable Variation ◽  
Pollinator Visitation ◽  
Pollination Success ◽  
Siring Success

Abstract Background Siring success plays a key role in plant evolution and reproductive ecology, and variation among individuals creates an opportunity for selection to act. Differences in male reproductive success can be caused by processes that occur during two stages, the pollination and post-pollination phases of reproduction. In the pollination phase, heritable variation in floral traits and floral display affect pollinator visitation patterns, which in turn affect variation among plants in the amount of pollen exported and deposited on recipient stigmas. In the post-pollination phase, differences among individuals in pollen grain germination success and pollen tube growth may cause realized paternity to differ from patterns of pollen receipt. The maternal plant can also preferentially provision some developing seeds or fruits to further alter variation in siring success. Scope In this review, we describe studies that advance our understanding of the dynamics of the pollination and post-pollination phases, focusing on how variation in male fitness changes in response to pollen limitation. We then explore the interplay between pollination and post-pollination success, and how these processes respond to ecological factors such as pollination intensity. We also identify pressing questions at the intersection of pollination and paternity and describe novel experimental approaches to elucidate the relative importance of pollination and post-pollination factors in determining male reproductive success. Conclusions The relative contribution of pollination and post-pollination processes to variation in male reproductive success may not be constant, but rather may vary with pollination intensity. Studies that quantify the effects of pollination and post-pollination phases in concert will be especially valuable as they will enable researchers to more fully understand the ecological conditions influencing male reproductive success.

scholarly journals Selfing rates vary with floral display, pollinator visitation and plant density in natural populations of Mimulus ringens

2021 ◽  
Author(s):  
Dorothy A. Christopher ◽  
Jeffrey D. Karron ◽  
Wendy R. Semski ◽  
Patrick A. Smallwood ◽  
Dorset W. Trapnell ◽  
...  
Keyword(s):  
Plant Density ◽  
Natural Populations ◽  
Floral Display ◽  
Pollinator Visitation ◽  
Mimulus Ringens

scholarly journals Daily fluctuations in pollination effectiveness explain higher efficiency of native over exotic bees in Lepechinia floribunda (Lamiaceae)

2019 ◽  
Vol 125 (3) ◽  
pp. 509-520
Author(s):  
Matias Cristian Baranzelli ◽  
Santiago Benitez-Vieyra ◽  
Evangelina Glinos ◽  
Alejandra Trenchi ◽  
Silvina Córdoba ◽  
...  
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Quantitative Estimation ◽  
Pollen Grains ◽  
Bumble Bees ◽  
Accurate Estimation ◽  
Floral Display ◽  
Nectar Production ◽  
Lower Efficiency ◽  
Effectiveness And Efficiency

Abstract Background Despite Stebbins’ principle of the most efficient pollinator being proposed decades ago, the most important pollinators are still mainly identified using the frequency of visits to flowers. This shortcoming results in a gap between the characterization of the flower visitors of a plant species and a reliable estimation of the plant fitness consequences of the mutualistic interaction. The performance of a mutualistic visitor depends on its abundance, behaviour, effectiveness (pollen removal and deposition per unit time) and efficiency (seed set per unit time) conditioned by the temporal matching between pollinator activity and temporal patterns of maturation of the sexual functions of flowers. Although there have been recent attempts to provide a conceptual and methodological framework to characterize pollinators’ performance, few have combined all key elements of visitors and plants to provide an accurate estimation of pollinators’ performance under natural conditions. Methods We complement information on the flower biology and mating system of the sub-shrub Lepechinia floribunda (Lamiaceae) to provide a daily quantitative estimation of performance (effectiveness and efficiency) of the more abundant pollinators, i.e. native bumble-bees (Bombus spp.) and leafcutter bees (Megachile sp.), and the exotic honey-bee (Apis mellifera). Key Results Unlike honey-bees or leafcutter bees, native bumble-bees matched the daily pattern of nectar production and stigma receptivity, and showed higher effectiveness and efficiency. Despite the overabundance of honey-bees, visits occurred mainly when stigmas were not receptive, thus reducing the honey-bees’ overall performance. Conclusions Bumble-bees appear to be the most important pollinators and potential historical mediators of reproductive trait evolution in L. floribunda. Because the production of seeds by bumble-bees involved fewer pollen grains for plants and less investment in floral display than honey-bees, contemporary and expected changes in pollinator abundance may affect future L. floribunda floral evolution. If bumble-bees were to be further displaced by anthropogenic disturbance or by competition with honey-bees, their lower efficiency will select for a larger floral display increasing reproductive costs. This scenario may also impose selection to reduce dichogamy to match honey-bee foraging activity.

scholarly journals Below-ground competition alters attractiveness of an insect-pollinated plant to pollinators

AoB Plants ◽  
2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Floriane Flacher ◽  
Xavier Raynaud ◽  
Amandine Hansart ◽  
Benoît Geslin ◽  
Eric Motard ◽  
...  
Keyword(s):  
Competitive Interactions ◽  
Floral Traits ◽  
Floral Display ◽  
Pollinator Visitation ◽  
Flowering Season ◽  
Plant Fecundity ◽  
Negative Effect ◽  
Below Ground ◽  
Plant Level ◽  
Set Up

Abstract Competitive interactions between plants can affect patterns of allocation to reproductive structures through modulation of resource availability. As floral traits involved in plant attractiveness to pollinators can be sensitive to these resources, competition with any neighbouring species may influence the attractiveness of insect-pollinated plants. While pollination research has primarily focused on above-ground interactions, this study aims at investigating if the presence of a competitor plant can modulate neighbouring insect-pollinated plant attractiveness to pollinators and resulting fecundity, especially through below-ground competitive interactions for soil resources. We set up a plot experiment in which we grew an insect-pollinated plant, Sinapis alba (Brassicaceae), in a mixture dominated by a wind-pollinated plant, Holcus lanatus (Poaceae). Individuals of S. alba were either subjected to or isolated from (with buried tubes in the soil) below-ground competition. Across the flowering season, floral traits involved in attractiveness of S. alba and pollinator visitation were followed at the plot and plant level to investigate different scales of attractiveness. At the end of the experiment, seeds were harvested to assess plant fecundity. Competition had a significant negative effect on plot and plant floral display size as well as flower size while nectar traits were not affected. When plants of S. alba were in competition, the time to first visit was altered: the proportion of plots that received a visit was smaller for a given time; in other words, it took more time for a given proportion of plots to be visited and some plots were even never visited. Moreover, pollinators made fewer visits per plots. The proportion of viable seeds produced by S. alba in competition was lower and probably linked to the competition itself rather than changes in pollinator visitation. This study suggests that competitive interactions between plants can modulate pollination interactions even when competing plant species are not insect-pollinated.

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