Why does the flower of Lonicera japonica open at dusk?

1998 ◽  
Vol 76 (10) ◽  
pp. 1806-1811 ◽  
Author(s):  
Takashi Miyake ◽  
Tetsukazu Yahara
Keyword(s):  
Pollen Grains ◽  
The Other ◽  
Lonicera Japonica ◽  
Pollination Syndrome ◽  
Pollen Transfer ◽  
Pollination Syndromes ◽  
Pollen Removal ◽  
Hawkmoth Pollination ◽  
Effective Pollinators ◽  
Pollen Consumption

We investigated contributions of diurnal pollinators and a nocturnal pollinator to pollen transfer in Lonicera japonica (Caprifoliaceae), whose flowers have traits typical of the hawkmoth-pollination syndrome. Diurnal bees, Tetralonia nipponensis and Lasioglossum sp., delivered more pollen grains than the nocturnal hawkmoth Theretra japonica per visit, suggesting that these bees were also effective pollinators. However, these bees removed over 10 times more pollen at one visit than the hawkmoth. Because of the higher pollen consumption by these bees, anthesis at dusk is considered to be optimal for Lonicera japonica to maximize overall pollen transfer under the visitation of both nocturnal and diurnal pollinators. Tetralonia japonica dispersed color dye farther than the other pollinators, which suggests that the nocturnal pollinator contributes more to cross-pollination than the diurnal pollinators.Key words: Lonicera japonica, hawkmoth-pollinated flowers, pollinator efficiency, pollen removal, pollination syndromes, timing of anthesis.

scholarly journals Generalist birds outperform specialist sunbirds as pollinators of an African Aloe

2019 ◽  
Vol 15 (7) ◽  
pp. 20190349 ◽  
Author(s):  
Carolina Diller ◽  
Miguel Castañeda-Zárate ◽  
Steven D. Johnson
Keyword(s):  
Seed Production ◽  
Pollen Grains ◽  
Pollen Transfer ◽  
Bird Pollination ◽  
Single Visit ◽  
Highly Effective ◽  
Aloe Ferox ◽  
Pollination Systems ◽  
Effective Pollinators

Bird pollination systems are dominated by specialist nectarivores, such as hummingbirds in the Americas and sunbirds in Africa. Opportunistic (generalist) avian nectarivores such as orioles, weavers and bulbuls have also been implicated as plant pollinators, but their effectiveness as agents of pollen transfer is poorly known. Here, we compare the single-visit effectiveness of specialist and opportunistic avian nectarivores as pollinators of Aloe ferox, a plant that relies almost exclusively on birds for seed production. We found that the number of pollen grains on stigmas of flowers receiving single visits by opportunistic avian nectarivores was approximately threefold greater than on those receiving single visits by specialist sunbirds and about twofold greater than on those that received single visits by honeybees. The number of pollen grains on stigmas of flowers visited by sunbirds was similar to that on stigmas of unvisited flowers. These results show that opportunistic birds are highly effective pollinators of A. ferox , supporting the idea that some plants are specialized for pollination by opportunistic birds.

Functional differentiation in pollination processes between the outer and inner perianths in Iris gracilipes (Iridaceae)

2006 ◽  
Vol 84 (1) ◽  
pp. 164-171 ◽  
Author(s):  
Shin-Ichi Morinaga ◽  
Satoki Sakai
Keyword(s):  
Genetic Correlation ◽  
Seed Production ◽  
Pollen Grains ◽  
Functional Differentiation ◽  
The Other ◽  
Pollination Success ◽  
Other Hand ◽  
Pollen Removal

We examined the functional differentiation in pollination processes between the outer and inner perianths in Iris gracilipes A. Gray flowers. We manipulated the length of the outer and inner perianths and examined the effect on the following: number of pollinator approaches to, and landings on, flowers; pollen removal and deposition during a single pollinator visit; total number of pollen grains removed; and seed production. The outer perianths contributed to the functions of pollinator approach and landing, pollen removal, and seed production, but not to mechanical fitting of pollinators. Since flowers with shortened outer perianths gained less pollination success than control flowers, and since lengthening of outer perianths did not enhance pollination success, the length of the outer perianths might have evolved as an adaptive characteristic. On the other hand, the inner perianths contributed to the functions of pollinator approach and pollen removal but not to pollinator landing, mechanical fitting of pollinators, nor seed production. Since flowers with shortened inner perianths gained pollination success similar to that of control flowers, the adaptive length of the inner perianths may be shorter than what is found in present-day flowers. We propose that genetic correlation between the outer and the inner perianths might prevent shortening of the inner perianths.

scholarly journals Pollinator effectiveness and importance between female and male mining bee ( Andrena )

2019 ◽  
Vol 15 (10) ◽  
pp. 20190479 ◽  
Author(s):  
Ju Tang ◽  
Qiu-Mei Quan ◽  
Jing-Zhu Chen ◽  
Ting Wu ◽  
Shuang-Quan Huang
Keyword(s):  
Foraging Behaviour ◽  
Pollen Grains ◽  
Pollen Foraging ◽  
Pollen Transfer ◽  
Natural Ecosystems ◽  
Pollinator Effectiveness ◽  
Visit Frequency ◽  
Pollen Transfer Efficiency ◽  
Food Provision ◽  
Effective Pollinators

Bees are often considered to be effective pollinators in both agricultural and natural ecosystems but could be ineffective pollinators in that they collect large quantities of pollen for food provision but deliver little to stigmas. Male bees do not collect pollen to feed larvae, and their pollination role has been underappreciated. Here we compare pollination effectiveness, visit frequency and pollen foraging behaviour between female and male individuals of a mining bee, Andrena emeishanica , visiting a nectariferous spring flower ( Epimedium pubescens ). Female bees were observed to forage for both pollen and nectar, but male bees foraged only for nectar. Female bees had large hairy hind tibiae with conspicuous scopae, and nearly 90% of the pollen grains they collected went onto the hind legs. Male bees removed less pollen from anthers than female bees but deposited more pollen on stigmas per visit. The higher pollen transfer efficiency of male bees was due to 48.4% of pollen grains remaining ungroomed on the thorax and abdomen, available for stigma contact, but their visitation rate to flowers was much lower. Our results indicate that male solitary bees could transfer more pollen on the stigma per visit but were less important (transferred less pollen in total, because they made fewer visits per unit time) than females.

scholarly journals Some Unresolved Issues of Measuring the Efficiency of Pollinators: Experimentally Testing and Assessing the Predictive Power of Different Methods

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Ram Chander Sihag
Keyword(s):  
Foraging Behavior ◽  
Seed Set ◽  
Reproductive Potential ◽  
Pollen Grains ◽  
The Other ◽  
Transfer Efficiency ◽  
Optimum Number ◽  
Pollen Transfer ◽  
Pollen Transfer Efficiency ◽  
Northwest India

Knowledge of efficiency of pollinators is valuable in the derivation of (i) the degree of mutualism specialization of a flower visitor in the natural plant communities, (ii) the optimum number of pollinators needed for the maximum pollination in a plant population, and (iii) the pollinator risk assessment in the sustainable agriculture. Earlier researchers used many direct and indirect methods for measuring the pollination efficiency (PE) of flower visitors. However, a great ambiguity exists in the usage of this terminology that necessitated its fresh scrutiny. I tested the available three standard methods afresh to find the efficiency of pollinators. These included comparing the (i) number of pollen grains removed and deposited by the visitors; (ii) seed set resulting from a single and the multiple visits of the visitors; and (iii) “pollen transfer efficiency (PTE)” derived from the foraging behavior and abundances of the visitors. Observations were recorded on the visitors of four plant species in an agroecosystem of Northwest India. These plants represented a wide variety of the floral types across the angiosperms. The first two methods, namely, the “number of pollen grains removed and deposited” and the “seed set resulting from a single and the multiple visits,” were appropriate in finding differences between the efficiency ranks of the pollinators of those flowers where the number of deposited pollen grains was less than the number of ovules in the ovary. However, these two methods completely failed in situations where exactly reverse condition of pollen grains and ovules existed. Thus, these two methods of measuring the PE of visitors had limited approach and lacked a universal application over the entire angiosperm taxa. On the other hand, use of “pollen transfer efficiency”, derived from the foraging behavior and abundance of the visitors, seemed to have an edge over the other two methods as this was helpful in finding differences between the efficiency ranks of the pollinators of plants in all the three situations tested in this study. However, validation of all the three methods through the plant reproductive potential seemed to be an integral confirmatory step for drawing inferences about the efficiency of pollinators.

Aspidistra revoluta, a new species from limestone areas in Chongqing, China

Phytotaxa ◽  
2016 ◽  
Vol 257 (3) ◽  
pp. 280 ◽  
Author(s):  
Hao Zhou ◽  
Si-rong Yi ◽  
Qi Gao ◽  
Jie Huang ◽  
Yu-jing Wei
Keyword(s):  
New Species ◽  
Chromosome Number ◽  
Average Length ◽  
Chromosome Complement ◽  
Pollen Grains ◽  
The Other ◽  
Morphological Comparison ◽  
Chongqing Municipality ◽  
Karyotype Asymmetry ◽  
A New Species

Aspidistra revoluta (Asparagaceae) is described and illustrated as a new species from limestone areas in southern Chongqing Municipality, China. The new species can be distinguished from the other Aspidistra species by its unique umbrella-like pistil with large revolute stigma lobes that bent downwards and touch the base of the perigone. A detailed morphological comparison among A. revoluta, A. nanchuanensis and A. carnosa is provided. The pollen grains of A. revoluta are subspherical and inaperturate, with verrucous exine. The chromosome number is 2n = 38, and the karyotype is formulated as 2n = 22m + 6sm + 10st. The average length of chromosome complement is 4.50 μm, and the karyotype asymmetry indexes A1 and A2 are respectively 0.37±0.03 and 0.49±0.01.

scholarly journals Why so many flowers? A preliminary assessment of mixed pollination strategy enhancing sexual reproduction of the invasive <i>Acacia longifolia</i> in Portugal

Web Ecology ◽  
2018 ◽  
Vol 18 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Manuela Giovanetti ◽  
Margarida Ramos ◽  
Cristina Máguas
Keyword(s):  
Invasive Plant ◽  
Seed Set ◽  
Pollen Grains ◽  
Striking Difference ◽  
Pollination Syndromes ◽  
Pollination Success ◽  
Relative Contribution ◽  
Acacia Longifolia ◽  
Exclusion Experiments ◽  
Pollination Strategy

Abstract. Acacia longifolia, a native legume from Australia, has been introduced in many European countries and elsewhere, thus becoming one of the most important global invasive species. In Europe, its flowering occurs in a period unsuitable for insect activity: nonetheless it is considered entomophilous. Floral traits of this species are puzzling: brightly coloured and scented as liked by insects, but with abundant staminate small-sized flowers and relatively small pollen grains, as it is common in anemophilous species. Invasion processes are especially favoured when reshaping local ecological networks, thus the interest in understanding pollination syndromes associated with invasive plant species that may facilitate invasiveness. Moreover, a striking difference exists between its massive flowering and relatively poor seed set. We introduced a novel approach: first, we consider the possibility that a part of the pollination success is carried on by wind and, second, we weighted the ethological perspective of the main pollinator. During the flowering season of A. longifolia (February–April 2016), we carried on exclusion experiments to detect the relative contribution of insects and wind. While the exclusion experiments corroborated the need for pollen vectors, we actually recorded a low abundance of insects. The honeybee, known pollinator of acacias, was relatively rare and not always productive in terms of successful visits. While wind contributed to seed set, focal observations confirmed that honeybees transfer pollen when visiting both the inflorescences to collect pollen and the extrafloral nectaries to collect nectar. The mixed pollination strategy of A. longifolia may then be the basis of its success in invading Portugal's windy coasts.

Pollen morphology of Sabinaria magnifica (Cryosophileae, Coryphoideae, Arecaceae)

Phytotaxa ◽  
2015 ◽  
Vol 207 (1) ◽  
pp. 135 ◽  
Author(s):  
Giovanni Raul Bogota ◽  
Carina Hoorn ◽  
Wim Star ◽  
Rob Langelaan ◽  
Hannah Banks ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
The Other ◽  
Transmission Electron ◽  
Palm Species ◽  
Scanning Electron

Sabinaria magnifica is so far the only known species in the recently discovered tropical palm genus Sabinaria (Arecaceae). Here we present a complete description of the pollen morphology of this palm species based on light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We also made SEM-based comparisons of Sabinaria with other genera within the tribe Cryosophileae. Pollen grains of Sabinaria magnifica resemble the other genera in the heteropolar, slightly asymmetric monads, and the monosulcate and tectate exine with perforate surface. Nevertheless, there are some clear differences with Thrinax, Chelyocarpus and Cryosophila in terms of aperture and exine. S. magnifica differs from its closest relative, Itaya amicorum, in the exine structure. This study shows that a combination of microscope techniques is essential for the identification of different genera within the Cryosophileae and may also be a necessary when working with other palynologically less distinct palm genera. 

Types of Flower Visitors: Syndromes, Constancy, and Effectiveness

2011 ◽  
Author(s):  
Pat Willmer
Keyword(s):  
Adaptive Radiation ◽  
Convergent Evolution ◽  
Pollination Syndromes ◽  
Pollinator Effectiveness ◽  
Flower Constancy ◽  
Flower Visitors ◽  
Floral Constancy ◽  
Effective Pollinators

This chapter examines pollination syndromes, floral constancy, and pollinator effectiveness. Flowers show enormous adaptive radiation, but the same kind of flower reappears by convergent evolution in many different families. Thus many families produce rather similar, simple bowl-shaped flowers like buttercups; many produce similar zygomorphic tubular lipped flowers; and many produce fluffy flower heads of massed (often white) florets. These broad flower types are the basis of the idea of pollination syndromes—the flowers have converged on certain morphologies and reward patterns because they are exploiting the abilities and preferences of particular kinds of visitor. After providing an overview of pollination syndromes, the chapter explains why pollination syndromes can be defended. It then considers flower constancy, along with the distinction between flower visitors and effective pollinators. It concludes with some observations on how flower visitors can contribute to speciation of plants through specialization and through their constancy.

scholarly journals Palynology of the Genus Stachytarpheta Vahl. (Verbenaceae)

2010 ◽  
Vol 2 (4) ◽  
pp. 27-33
Author(s):  
Olubukola ADEDEJI
Keyword(s):  
Cluster Analysis ◽  
Grain Size ◽  
Evolutionary History ◽  
Pollen Grains ◽  
Pollen Grain ◽  
The Other ◽  
Pollen Grain Size ◽  
Pollen Diameter ◽  
Stachytarpheta Cayennensis ◽  
Exine Morphology

The exine morphology of pollen grains of Stachytarpheta indica (Linn.) Vahl, Stachytarpheta cayennensis (Rich.) Vahl and Stachytarpheta angustifolia (Mill.) Vahl is reported. This study was carried out with a light microscope. Pollen grains from fresh anthers were collected and aceolysed. Statistical analysis used to analyse the data collected include cluster analysis, correlation analysis, similarity and distance indices. The pollen grains are spheroidal to oblate to sub-oblate in shape. They are aperturate, both colpate and porate. Tricolpate types occur most frequently, acolpate, monocolpate, bicolpate and tetracolpate types less frequently. The multicolpate and multiporate attributes in all the species indicate that the genus is not primitive in evolutionary history and this species probably, evolved around in the same time. According to the size, the pollen grains of the genus falls into groups permagna (pollen diameter 100-200 μm) and giganta (pollen diameter greater than 200 μm). S. cayennensis and S. anguistifolia belong to group permagna and S. indica only in the group giganta. This separates S. indica from the other two species. The large pollen grain size in the genus clearly supports the fact that the flowers in the genus are more insect-and-bird pollinated than wind pollinated. The similarity and distance indices of the species showed that S. cayennensis and S. angustifolia are the closest. S. indica is closer to S. angustifolia but farther from S. cayennensis.

scholarly journals Pollinator effectiveness of a specialist bee exploiting a generalist plant—tracking pollen transfer by Heriades truncorum with quantum dots

Apidologie ◽  
2019 ◽  
Vol 51 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Sabine Konzmann ◽  
Margareta Kluth ◽  
Deniz Karadana ◽  
Klaus Lunau
Keyword(s):  
Quantum Dots ◽  
Reproductive Success ◽  
Pollen Germination ◽  
Pollen Grains ◽  
Pollen Transfer ◽  
Pollinator Effectiveness ◽  
Flower Constancy ◽  
Single Visit ◽  
Heriades Truncorum ◽  
Open Control

AbstractHeriades truncorum (Megachilidae) is a specialist bee that forages on Asteraceae and collects pollen by tapping its abdomen on pollen-presenting florets which places the grains directly in the ventral scopa. We tracked pollen transfer by female H. truncorum between conspecific inflorescences of Inula ensifolia and Pulicaria dysenterica by labelling pollen with quantum dots. On average, bees transferred 31.14 (I. ensifolia) and 9.96 (P. dysenterica) pollen grains from the last visited inflorescence, 39% and 45% of which were placed on receptive styles. Pollen germination ratio is significantly lower for inflorescences of P. dysenterica visited by one H. truncorum (0.13%) compared with open control inflorescences (0.51%), which suggests that the bees mainly transfer self-pollen of these self-incompatible plants. Thus, a single visit by H. truncorum does not grant the plant high reproductive success, but the bees’ abundance and flower constancy might reduce this disadvantage.

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