Heterospecific pollen deposition is positively associated with reproductive success in a diverse hummingbird‐pollinated plant community

Sexual dimorphism can have implications in the reproductive biology of gynodioecious species, affecting sex fitness. We explored the effects of flower sex on pollination visitation rates and pollinator efficiency in terms of stigmatic pollen loads, as well as on quantitative and qualitative aspects of reproductive success in two populations of Thymus loscosii Willk. (Lamiaceae) endemic to the northeastern Iberian Peninsula. We also assessed the dependence of T. loscosii on insect pollination in both hermaphrodite and female plants by performing an insect exclusion test. Apis mellifera and different species of Bombylidae were the most frequent pollinators (68% of approaches to studied plots and 93% of total visited flowers). Hermaphrodite plants received more visits than female ones, possibly as a response to visual attraction, since flowers of the former are larger. Conspecific pollen deposition was higher on stigmas of hermaphrodite flowers than on those of females; in contrast, female stigmas received more heterospecific pollen loads, notably higher in one population. Despite these differences, seed set from open-pollinated flowers was similar in both sexes and in both populations, and relatively low (around 0.51 nutlet per fruiting calyx, on average). Thymus loscosii is self-compatible as it was able to produce seeds by spontaneous selfing, but at very low rates, indicating that it is insect-dependent for pollination. In addition, bagged female flowers also set seeds formed by apomitic mechanisms. In general, seeds from females were slightly heavier and began to germinate earlier and at higher rates than those from hermaphrodites, even those formed by apomixis. These results suggest that female plants enjoy a resource allocation advantage that allows increased seed quality and contributes to the maintenance of gynodioecy.Key words: gynodioecy, pollinator visitation, pollen loads, seed set, sex fitness, Thymus loscosii.

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Heterospecific pollen deposition inDelphinium barbeyi: linking stigmatic pollen loads to reproductive output in the field

Annals of Botany ◽

10.1093/aob/mcv175 ◽

2015 ◽

pp. mcv175 ◽

Cited By ~ 2

Author(s):

Heather M. Briggs ◽

Lucy M. Anderson ◽

Laila M. Atalla ◽

André M. Delva ◽

Emily K. Dobbs ◽

...

Keyword(s):

Reproductive Output ◽

Pollen Deposition ◽

Heterospecific Pollen ◽

Pollen Loads ◽

Heterospecific Pollen Deposition

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Effect of heterospecific pollen deposition on pollen tube growth depends on the phylogenetic relatedness between donor and recipient

AoB Plants ◽

10.1093/aobpla/plaa016 ◽

2020 ◽

Vol 12 (4) ◽

Author(s):

Nathália Susin Streher ◽

Pedro Joaquim Bergamo ◽

Tia-Lynn Ashman ◽

Marina Wolowski ◽

Marlies Sazima

Keyword(s):

Pollen Tube ◽

Plant Species ◽

Flowering Plant ◽

Pollen Deposition ◽

Phylogenetic Relatedness ◽

Pollination Success ◽

Heterospecific Pollen ◽

Flowering Plant Species ◽

Heterospecific Pollen Deposition ◽

Pollen Effect

Abstract Co-flowering plant species may interact via pollinators leading to heterospecific pollen transfer with consequences for plant reproduction. What determines the severity of heterospecific pollen effect on conspecific pollen performance is unclear, but it may depend on the phylogenetic relatedness of the interactors (pollen donors and recipient). The heterospecific pollen effect might also depend on the extent to which plants are exposed to heterospecific pollen over ecological or evolutionary timescales. For instance, generalist-pollinated plant species might tolerate heterospecific pollen more than specialists. Here, we tested whether heterospecific pollen effects are stronger between closely related species than phylogenetically distant ones in a tropical highland community. Then, based on these results, we determined whether responses to heterospecific pollen were stronger in generalized vs. specialized plant species. We applied heterospecific pollen from close (congeneric) or distant (different families) donors alone or with conspecific pollen on stigmas of three recipient species (one generalist, Sisyrinchium wettsteinii; and two specialists, Fuchsia campos-portoi and Fuchsia regia) and scored pollen tube performance in styles. In all species, pollen from closely related donors grew pollen tubes to the base of the style indicating a high potential to interfere with seed set. Conversely, distantly related heterospecific pollen had no effect on either specialist Fuchsia species, whereas enhanced performance of conspecific pollen was observed in generalist S. wettsteinii. The strong effect of phylogenetic relatedness of donor and recipient might have obscured the role of pollination specialization, at least for the three species examined here. Therefore, phylogenetic relatedness mediated the effect of heterospecific pollen on post-pollination success, with possible consequences for reproductive trait evolution and community assembly for further studies to explore.

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Importance of Pollinator-Mediated Interspecific Pollen Transfer for Angiosperm Evolution

Annual Review of Ecology Evolution and Systematics ◽

10.1146/annurev-ecolsys-110218-024804 ◽

2019 ◽

Vol 50 (1) ◽

pp. 191-217 ◽

Cited By ~ 16

Author(s):

Juan Isaac Moreira-Hernández ◽

Nathan Muchhala

Keyword(s):

Character Displacement ◽

Pollen Deposition ◽

Pollen Transfer ◽

Reproductive Character Displacement ◽

Pollinator Attraction ◽

Angiosperm Evolution ◽

Heterospecific Pollen ◽

Interspecific Pollen Transfer ◽

Angiosperm Diversification ◽

Heterospecific Pollen Deposition

Understanding how pollen moves between species is critical to understanding speciation, diversification, and evolution of flowering plants. For co-flowering species that share pollinators, competition through interspecific pollen transfer (IPT) can profoundly impact floral evolution, decreasing female fitness via heterospecific pollen deposition on stigmas and male fitness via pollen misplacement during visits to heterospecific flowers. The pollination literature demonstrates that such reproductive interference frequently selects for reproductive character displacement in floral traits linked to pollinator attraction, pollen placement, and mating systems and has also revealed that IPT between given pairs of species is typically asymmetric. More recent work is starting to elucidate its importance to the speciation process, clarifying the link between IPT and current and historical patterns of hybridization, the evolution of phenotypic novelty through adaptive introgression, and the rise of reproductive isolation. Our review aims to stimulate further research on IPT as a ubiquitous mechanism that plays a central role in angiosperm diversification.

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Differential Tolerance to Increasing Heterospecific Pollen Deposition in Two Sympatric Species of Burmeistera (Campanulaceae: Lobelioideae)

International Journal of Plant Sciences ◽

10.1086/705735 ◽

2019 ◽

Vol 180 (9) ◽

pp. 987-995 ◽

Cited By ~ 2

Author(s):

Juan Isaac Moreira-Hernández ◽

Nicholas Terzich ◽

Ricardo Zambrano-Cevallos ◽

Nora H. Oleas ◽

Nathan Muchhala

Keyword(s):

Sympatric Species ◽

Pollen Deposition ◽

Heterospecific Pollen ◽

Heterospecific Pollen Deposition

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Heterospecific pollen deposition among plants sharing hummingbird pollinators in the Brazilian Atlantic Forest

Rodriguésia ◽

10.1590/2175-7860201667205 ◽

2016 ◽

Vol 67 (2) ◽

pp. 335-345 ◽

Cited By ~ 6

Author(s):

Lorena Coutinho Nery da Fonseca ◽

André Rodrigo Rech ◽

Pedro Joaquim Bergamo ◽

Vania Gonçalves-Esteves ◽

Marlies Sazima

Keyword(s):

Plant Species ◽

Atlantic Forest ◽

Temporal Organization ◽

Pollen Deposition ◽

Brazilian Atlantic Forest ◽

Body Parts ◽

Heterospecific Pollen ◽

Negative Effect ◽

Pollen Mixture ◽

Heterospecific Pollen Deposition

Abstract Hummingbirds are the most important group of pollinating birds in the Neotropics and tend to use, concomitantly, more than one plant species as food source. Pollen may be mixed on hummingbirds' body due to the visits to different plant species; therefore, these birds may promote heterospecific pollen deposition (HPD). The hummingbirds potential to promote HPD, the occurrence of HPD and its implications in plant reproduction are scarcely known in the Atlantic Forest. We have studied the transport of pollen by three hummingbird species from the Brazilian Atlantic Forest. We have also checked the actual HPD occurrence under natural conditions in two plant species, namely Canistropsis seidelii and Psychotria nuda. Moreover, we investigated Nidularium innocentii reproductive system evaluating the effect of HPD on its reproduction by simulating a pollen mixture pollination. We found hummingbirds transporting heterospecific pollen mixtures on their bodies, which in turn were deposited onto stigmas of different species. We have also found that mixed pollen deposition had negative effect on the fitness of N. innocentii. We conclude that hummingbirds carry pollen mixtures at the same body parts, leading to potential HPD at the community level. Moreover, hummingbird-plant communities in the Atlantic Rainforest show remarkable similarities in temporal organization and interaction pattern. This suggests that HPD may be a widespread phenomena in these communities.

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Heterospecific pollen deposition: does diversity alter the consequences?

New Phytologist ◽

10.1111/j.1469-8137.2011.03831.x ◽

2011 ◽

Vol 192 (3) ◽

pp. 738-746 ◽

Cited By ~ 54

Author(s):

Gerardo Arceo-Gómez ◽

Tia-Lynn Ashman

Keyword(s):

Pollen Deposition ◽

Heterospecific Pollen ◽

Heterospecific Pollen Deposition

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Do abundance and proximity of the alien Impatiens glandulifera affect pollination and reproductive success of two sympatric co-flowering native species?

Journal of Pollination Ecology ◽

10.26786/1920-7603(2012)16 ◽

2012 ◽

Vol 10 ◽

pp. 130-139

Author(s):

Valérie Cawoy ◽

Mathieu Jonard ◽

Carolin Mayer ◽

Anne-Laure Jacquemart

Keyword(s):

Reproductive Success ◽

Native Species ◽

Natural Populations ◽

Pollen Deposition ◽

Impatiens Glandulifera ◽

Insect Behaviour ◽

Native Flora ◽

Visitation Rates ◽

Aconitum Napellus ◽

Negative Effect

In invasion ecology, potential impacts of aliens on native flora are still under debate. Our aim was to determine the pollinator mediated effects of both proximity and abundance of an alien species on the reproductive success of natives. We chose the highly invasive Impatiens glandulifera and two native species: Epilobium angustifolium and Aconitum napellus ssp. lusitanicum. These species share characteristics allowing for pollination interactions: similar biotopes, overlapping flowering periods and same main pollinators. The effects of abundance (5, 25 and 100 individuals) and proximity (0 and 15 m) of the alien on visitation rate, insect behaviour, pollen deposition and reproductive success of both natives were investigated during 2 flowering seasons. We used centred visitation rates as they can be directly interpreted as a positive or negative effect of the invasive.Both abundance and proximity of the alien increased bumblebee visitation rates to both natives. On the other hand, abundance of the exotic species had a slight negative effect on honeybee visits to natives while its proximity had no effect. The behaviour of bumblebees changed as visitors left significantly more often the native plants for I. glandulifera when its abundance increased. As a consequence of this “inconstancy”, bees deposited considerable quantities of alien pollen on native stigmas. Nevertheless, this interspecific pollen transfer did not decrease seed set in natives. Self-compatibility and high attractiveness of both native species probably alleviate the risk of altered pollinator services and reproductive success due to the invader in natural populations.

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