scholarly journals Comparative effects of pollen limitation, floral traits and pollinators on reproductive success of Hedysarum scoparium Fisch. et Mey. in different habitats

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Min Chen ◽  
Xue-Yong Zhao ◽  
Xiao-An Zuo ◽  
Shao-Kun Wang ◽  
Hao Qu ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Seed Set ◽  
Pollen Limitation ◽  
Positive Association ◽  
Floral Traits ◽  
Limiting Factor ◽  
Pollinator Visitation ◽  
Open Flower ◽  
Visitation Frequency ◽  
The Difference

Abstract Background Reproduction in most flowering plants may be limited because of the decreased visitation or activity of pollinators in fragmented habitats. Hedysarum scoparium Fisch. et Mey. is an arid region shrub with ecological importance. We explored the pollen limitation and seed set of Hedysarum scoparium in fragmented and restored environments, and examined whether pollen limitation is a significant limiting factor for seed set. We also compared floral traits and pollinator visitation between both habitats, and we determined the difference of floral traits and pollinators influenced reproductive success in Hedysarum scoparium. Results Our results indicated that supplementation with pollen significantly increased seed set per flower, which is pollen-limited in this species. Furthermore, there was greater seed set of the hand cross-pollination group in the restored habitat compared to the fragmented environment. More visits by Apis mellifera were recorded in the restored habitats, which may explain the difference in seed production between the fragmented and restored habitats. Conclusions In this study, a positive association between pollinator visitation frequency and open flower number was observed. The findings of this study are important for experimentally quantifying the effects of floral traits and pollinators on plant reproductive success in different habitats.

scholarly journals Spatiotemporal Variations in Seed Set and Pollen Limitation in Populations of the Rare Generalist Species Polemonium caeruleum in Poland

2022 ◽  
Vol 12 ◽  
Author(s):  
Justyna Ryniewicz ◽  
Katarzyna Roguz ◽  
Paweł Mirski ◽  
Emilia Brzosko ◽  
Mateusz Skłodowski ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Population Size ◽  
Seed Production ◽  
Seed Set ◽  
Pollen Limitation ◽  
Monthly Precipitation ◽  
Small Populations ◽  
Flower Visitors ◽  
Visitation Frequency ◽  
Average Monthly Precipitation

A vast majority of angiosperms are pollinated by animals, and a decline in the number and diversity of insects often affects plant reproduction through pollen limitation. This phenomenon may be particularly severe in rare plant species, whose populations are shrinking. Here, we examined the variability in factors shaping reproductive success and pollen limitation in red-listed Polemonium caeruleum L. During a 5-year study in several populations of P. caeruleum (7–15, depending on year), we assessed the degree of pollen limitation based on differences in seed set between open-pollinated (control) and hand-pollinated flowers. We analysed the effects of flower visitors, population size, and meteorological data on plant reproductive success and pollen limitation. Our study showed that pollen limitation rarely affected P. caeruleum populations, and was present mainly in small populations. Pollen limitation index was negatively affected by the size of population, visitation frequency of all insects, and when considering the visitation frequency of individual groups, also by honeybee visits. Seed production in control treatment was positively influenced by the population size, average monthly precipitation in June and visits of hoverflies, while visits of honeybees, average monthly temperature in September, and average monthly precipitation in August influenced seed production negatively. As generalist plant P. caeruleum can be pollinated by diverse insect groups, however, in small populations their main visitors, the honeybees and bumblebees, may be less attracted, eventually leading to the disappearance of these populations. In pollination of P. caeruleum managed honeybees may play a dual role: while they are the most frequent and efficient flower visitors, their presence decreases seed set in open-pollinated flowers, which is most probably related to efficient pollen collection by these insects.

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.

Pollination and reproductive success in the gynodioecious endemic Thymus loscosii (Lamiaceae)

2005 ◽  
Vol 83 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Maria Renée Orellana ◽  
Anna Maria Rovira ◽  
Cèsar Blanché ◽  
Maria Bosch
Keyword(s):  
Reproductive Success ◽  
Seed Quality ◽  
Seed Set ◽  
Pollen Deposition ◽  
Pollinator Visitation ◽  
Heterospecific Pollen ◽  
Pollen Loads ◽  
Visual Attraction ◽  
Insect Exclusion ◽  
Two Populations

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 0.5–1 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.

Visitation frequency of Melampyrum roseum var. japonicum (Scrophulariaceae) by three bumblebee species and its relation to pollination efficiency

2001 ◽  
Vol 79 (10) ◽  
pp. 1167-1174 ◽  
Author(s):  
Kayako Hiei ◽  
Kazuo Suzuki
Keyword(s):  
Reproductive Success ◽  
Seed Set ◽  
Pollination Efficiency ◽  
Experimental Conditions ◽  
Bumblebee Species ◽  
Single Visit ◽  
Pollination Effectiveness ◽  
Visitation Frequency ◽  
Pollen Removal

The efficiency of pollination of Melampyrum roseum Maximowicz var. japonicum Franchet et Savatier by three bumblebee species, Bombus consobrinus Vogt, Bombus diversus Smith, and Bombus honshuensis Tkalců, which differ especially in proboscis length, was examined under experimental conditions where visitation frequencies were controlled. First, we found that B. honshuensis, with the shortest proboscis, deposited the most pollen per stigma, resulting in the highest seed set in single visit experiments among the three bumblebee species, while B. diversus removed the most pollen from the anthers. The morphological match between pollinators and flowers was found to be an important factor affecting the per-visit pollination intensity mentioned above. Second, we found that seed set and pollen removal increased when flowers were visited twice by any of the three bumblebee species and that the differences among the three bumblebee species disappeared. When flowers were visited three or four times, the seed set and pollen removal did not increase further. These findings indicate that pollination effectiveness may differ among the bumblebee species only when flowers are infrequently visited by any of the bumblebee species.Key words: Melampyrum roseum, bumblebees, pollination efficiency, reproductive success, seed set, visitation frequency.

Pollen limitation, species’ floral traits and pollinator visitation: different relationships in contrasting communities

Oikos ◽  
2014 ◽  
Vol 124 (2) ◽  
pp. 174-186 ◽  
Author(s):  
Amparo Lázaro ◽  
Rebekka Lundgren ◽  
Ørjan Totland
Keyword(s):  
Pollen Limitation ◽  
Floral Traits ◽  
Pollinator Visitation

scholarly journals Reproductive Ecology of Euglossine Bee-pollinated Orchid Catasetum Integerrimum Hook (Ochidaceae)

2021 ◽  
Author(s):  
Angélica María Hernández-Ramírez
Keyword(s):  
Pollen Limitation ◽  
Reproductive Ecology ◽  
Fruit Production ◽  
Floral Traits ◽  
Release Mechanism ◽  
Pollinator Visitation ◽  
Euglossine Bee ◽  
New Research ◽  
And Behavior

Abstract Catasetum is a dimorphic and dioecious genus of orchids with a pollinaria release mechanism triggered by pollinator visitation. The reproductive ecology of Catasetum integerrimum Hook (Orchidaceae) was characterized in Central Veracruz, Mexico. For that, it was determined whether floral senescence and fruit production are resulted of pollination efficiency in the species, and if so, to what extent present reproductive event constraint the investment in subsequent reproductive event. In the sampled population, efficient pollinaria removal/deposition triggered floral senescence. Eulaema polychroma bee visited earlier and with lower frequency the staminate than pistillate flowers. Alleviating pollen limitation increased fruit production but it caused a reduction in flower and fruit production in the subsequent reproductive event. C. integerrimum seemed to exhibit reproductive cost-saving mechanisms linked to the pollinator identity and behavior, whereas pollinator efficiency appeared to be mediated by dioecism and dimorphism in floral traits. This study highlights the importance to understand the adaptive significance of dimorphic floral traits in animal-pollinated plants, stimulating new research avenues on the role of pollinators in maintaining safe reproduction threshold of plants.

Pollen limitation and reproduction varies with population size in experimental populations of Sabatia angularis (Gentianaceae)

Botany ◽  
2009 ◽  
Vol 87 (3) ◽  
pp. 330-338 ◽  
Author(s):  
Rachel B. Spigler ◽  
Shu-Mei Chang
Keyword(s):  
Reproductive Success ◽  
Population Size ◽  
Intraspecific Competition ◽  
Seed Set ◽  
Pollen Limitation ◽  
Small Populations ◽  
Plant Populations ◽  
Large Populations ◽  
Fruit And Seed Set ◽  
Supplemental Pollination

Individuals in large plant populations are expected to benefit from increased reproductive success relative to those in small populations because of the facilitative effects of large aggregations on pollination. As populations become small, the inability to attract sufficient numbers of pollinators can reduce reproduction via pollen limitation. This study experimentally tested whether such trends occur for the herbaceous biennial Sabatia angularis (L.) Pursh (Gentianaceae). We created artificial populations of varying size consisting of potted S. angularis plants in two field sites to determine whether population size affected mean fruit and seed set. We also examined whether population size affected the degree of pollen limitation using a supplemental pollination design in one of the sites. Our results showed that, on average, seed set was lower in large populations, not small populations, of S. angularis and that this result may be due to increased pollen limitation in large populations. We suggest that in certain contexts, small populations may enjoy reproductive advantages over large populations by escaping intraspecific competition for pollinators.

Pollen limitation in an experimental population of the wild radish Raphanus raphanistrum

1997 ◽  
Vol 75 (1) ◽  
pp. 72-73
Author(s):  
Karin S. Pfennig ◽  
Jeffrey K. Conner
Keyword(s):  
Reproductive Success ◽  
Key Words ◽  
Fruit Set ◽  
Seed Set ◽  
Pollen Limitation ◽  
Experimental Population ◽  
Wild Radish ◽  
Raphanus Raphanistrum ◽  
Female Fitness ◽  
Female Reproductive Success

Experimental hand-pollinations were performed on a sample of wild radish, Raphanus raphanistrum, to determine whether female reproductive success was pollen limited. Fruit set was found to increase with receipt of supplemental pollen, but seed set did not. These results contradict findings in another Raphanus species but are expected if seeds are aborted or matured in packages. Key words: pollen limitation, Raphanus raphanistrum, female fitness.

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