Solitary bee pollinators adjust pollen foraging to the unpredictable flower opening of a species of Petunia (Solanaceae)

2019 ◽  
Vol 129 (2) ◽  
pp. 273-287
Author(s):  
Fernanda Figueiredo De Araujo ◽  
Reisla Oliveira ◽  
Theo Mota ◽  
João Renato Stehmann ◽  
Clemens Schlindwein
Keyword(s):  
Floral Biology ◽  
Floral Resources ◽  
Pollen Foraging ◽  
Flower Opening ◽  
Foraging Patterns ◽  
Social Species ◽  
Pollen Presentation ◽  
Total Pollen ◽  
Flower Visiting ◽  
Effective Pollinators

Abstract Details of the foraging patterns of solitary bees are much less well known than those of social species, and these patterns are often adjusted to exploit floral resources of one or only a few species. The specialized flower-visiting bees of Petunia are good models for investigating such foraging patterns. Here we analysed the floral biology and pollen presentation schedule of the endangered Petunia mantiqueirensis in mixed Araucaria forests of Serra da Mantiqueira, Brazil. Pollinators and their pollen foraging behaviour and food specialization were determined through analyses of scopa pollen loads. Flowers opened throughout the day and presented all their pollen resources within the first 30 min of anthesis, thus providing their pollen resources in an asynchronous fashion in one-flower packages throughout the day. Females of Pseudagapostemon fluminensis were the most frequent flower visitors, contacting stigmas in 96% of their visits, and were the unique effective pollinators of Petunia mantiqueirensis. These pollinators were responsible for the first three visits to 115 individually monitored flowers at any daylight hour, removing ~86% of a flower’s total pollen supply during the first visit. Although female bees harvest the majority of pollen resources of Petunia mantiqueirensis, analyses of scopa loads revealed that most of them also collect pollen from plants of other families while foraging for pollen in Petunia flowers.

Orchestrated Flowering and Interspecific Facilitation: Key Factors in the Maintenance of the Main Pollinator of Coexisting Threatened Species of Andean Wax Palms (Ceroxylon spp.)

2020 ◽  
Vol 105 (3) ◽  
pp. 281-299
Author(s):  
Javier Carreño-Barrera ◽  
Luis Alberto Núñez-Avellaneda ◽  
Maria José Sanín ◽  
Artur Campos D. Maia
Keyword(s):  
Conservation Status ◽  
Population Decline ◽  
Floral Biology ◽  
Fruit Production ◽  
Biological Data ◽  
Fruit Yield ◽  
Insect Species ◽  
Individual Species ◽  
Pollination Services ◽  
Flower Visiting

Solitary, dioecious, and mostly endemic to Andean cloud forests, wax palms (Ceroxylon Bonpl. ex DC. spp.) are currently under worrisome conservation status. The establishment of management plans for their dwindling populations rely on detailed biological data, including their reproductive ecology. As in the case of numerous other Neotropical palm taxa, small beetles are assumed to be selective pollinators of wax palms, but their identity and relevance in successful fruit yield were unknown. During three consecutive reproductive seasons we collected data on population phenology and reproductive and floral biology of three syntopic species of wax palms native to the Colombian Andes. We also determined the composition of the associated flower-visiting entomofauna, quantifying the extent of the role of individual species as effective pollinators through standardized value indexes that take into consideration abundance, constancy, and pollen transport efficiency. The studied populations of C. parvifrons (Engel) H. Wendl., C. ventricosum Burret, and C. vogelianum (Engel) H. Wendl. exhibit seasonal reproductive cycles with marked temporal patterns of flower and fruit production. The composition of the associated flower-visiting entomofauna, comprised by ca. 50 morphotypes, was constant across flowering seasons and differed only marginally among species. Nonetheless, a fraction of the insect species associated with pistillate inflorescences actually carried pollen, and calculated pollinator importance indexes demonstrated that one insect species alone, Mystrops rotundula Sharp, accounted for 94%–99% of the effective pollination services for all three species of wax palms. The sequential asynchronous flowering of C. parvifrons, C. ventricosum, and C. vogelianum provides an abundant and constant supply of pollen, pivotal for the maintenance of large populations of their shared pollinators, a cooperative strategy proven effective by high fruit yield rates (up to 79%). Reproductive success might be compromised for all species by the population decline of one of them, as it would tamper with the temporal orchestration of pollen offer.

The cost of fidelity: foraging oligolectic bees gather huge amounts of pollen in a highly specialized cactus–pollinator association

2019 ◽  
Vol 128 (1) ◽  
pp. 30-43 ◽  
Author(s):  
Isabelle Cerceau ◽  
Samuel Siriani-Oliveira ◽  
Ana Laura Dutra ◽  
Reisla Oliveira ◽  
Clemens Schlindwein
Keyword(s):  
Male Reproductive Success ◽  
Flower Opening ◽  
Mechanical Filter ◽  
Pollen Presentation ◽  
Oligolectic Bees ◽  
The Cost ◽  
Fruit And Seed Set ◽  
Flower Handling ◽  
Plant Pollinator ◽  
Pollinator Foraging Behaviour

Abstract Plant–pollinator interactions vary along a specialization–generalization continuum. Advances in understanding the evolutionary and ecological consequences of different degrees of specialization depend on precise data on plant–pollinator interdependency. We studied the association of Parodia neohorstii (Cactaceae) and its bee pollinators focusing on pollinator foraging behaviour, flower functioning, female and male reproductive success, and pollen fate. Parodia neohorstii showed synchronized flower opening and pollen presentation but discontinuous blooming. The apparently generalized flowers partition pollen through thigmonastic stamen movements that function as a mechanical filter against generalist bees by restricting access to the major pollen reservoir to bees that show flower handling ‘know-how’, thereby favouring the oligolectic bee Arhysosage cactorum. This pollinator adjusted its pollen foraging to flower opening, removed pollen hurriedly, and promoted maximal fruit and seed set, which was minimal in its absence. Estimates of pollen fate revealed that a huge amount of pollen flows to specialized pollinators (86.5%), and only 0.9% reaches conspecific stigmas. The specialized interaction between P. neohorstii and Arhysosage cactorum, both threatened species, is efficient but fragile. Any environmental modification that causes a mismatch between the partners is likely to result in reproductive failure.

Floral Biology and Self-Incompatibility in Some Australian Mistletoes of the Genus Amyema (Loranthaceae)

1980 ◽  
Vol 28 (4) ◽  
pp. 437 ◽  
Author(s):  
P Bernhardt ◽  
RB Knox ◽  
DM Calder
Keyword(s):  
Floral Biology ◽  
Self Incompatibility ◽  
Flower Buds ◽  
In Vitro Pollination ◽  
Mature Flower ◽  
Pollen Presentation ◽  
Self Compatibility ◽  
Safe Mechanism ◽  
Fail Safe

Facultative cleistogamy has not been found In some Austrahan Amyema spp , and the stigma does not functlon in pollen presentation at anthesis. Wlthin mature flower buds self-polllnatlon is prevented by morphological and physiological barriers, a protandrous condition largely prevents mechanical or zoophilous self-pollination In vitro pollination experiments revealed that xenogamous crosses are most successful In the production of pollen tubes in the style although geitonogamy may act as a 'fail safe mechanism' at varying levels under natural condltlons in A miquelii (Lehm, ex Miq) Van Tiegh, A. miraculosum (Miq ) Van Tiegh and A. penduium (Sieber ex Spreng ) Van Tiegh. Of the four species studied, A. quandang (Lindl ) Van Tiegh had the highest levels of self-compatibility.

scholarly journals Floral biology of Jatropha curcas L.

2010 ◽  
pp. 31-54
Author(s):  
Angelo Jay Noriel ◽  
Othello Capuno
Keyword(s):  
Jatropha Curcas ◽  
Floral Morphology ◽  
Sunshine Duration ◽  
Pollen Viability ◽  
Floral Biology ◽  
State University ◽  
Anther Dehiscence ◽  
Full Bloom ◽  
Flower Opening ◽  
Male Flowers

This study was conducted at the existing plantation of Jatropha curcas within the campus of Visayas State University, Visca, Baybay, Leyte from April 2006 to June 2006 with the following objectives: 1) to study the floral morphology and flowering behavior of J. curcas; 2) to determine the time and duration of flower opening, anther dehiscence, and stigmatic receptivity of J. curcas; and 3) to test for pollen viability. Male and female flowers of J. curcas were borne on the same plant with an average numbers per inflorescence of 55.03 and 1.926, respectively. Male flowers were more numerous than the females without definite relationship on number per inflorescence. It took an average of 9.56 days for all florets to full bloom. Anther dehiscence was observed to start at the time of opening of male flowers at around 0500 to 0600 hours and remained so for 24 to 72 hours. Stigmatic receptivity started about 12 hours after full bloom and lasted for about 24 hours. Based on observations, opening of floret buds, anther dehiscence, and stigmatic receptivity were all greatly influenced by the environment. Early sunrise, longer sunshine duration, and less amount of rainfall enhanced flowering of J. curcas. Pollen viability was relatively high, ranging from 88.12% to 98.55%.

scholarly journals Floral Morphology and Development in Georgia Plume, Elliottia racemosa (Ericaceae), a Rare Coastal Plain Endemic

2010 ◽  
Vol 135 (6) ◽  
pp. 487-493
Author(s):  
Carrie A. Radcliffe ◽  
James M. Affolter ◽  
Hazel Y. Wetzstein
Keyword(s):  
Coastal Plain ◽  
Developmental Stages ◽  
Pollen Viability ◽  
Natural Populations ◽  
Morphological Characteristics ◽  
Floral Biology ◽  
Flower Opening ◽  
Developmental Abnormalities ◽  
In The Wild

Georgia plume (Elliottia racemosa) is a threatened woody plant endemic to the Coastal Plain region of Georgia in the southeastern United States. Seed set is low in most populations, and sexual recruitment has not been observed in recent times. The objective of this study was to describe the floral biology of georgia plume. which is fundamental information needed to develop an understanding of the causes for lack of sexual reproduction in natural populations. Floral development was characterized and morphological characteristics at key developmental stages ranging from small, unopened buds to open flowers with receptive stigmas were examined using light and scanning electron microscopy. Flowering is protandrous, and anthers dehisce releasing pollen within closed buds before stigmas are receptive. Pollen tetrads, aggregated by viscin strands, are presented on unreceptive stigmas when petals reflex. Receptive stigmas developed a raised and lobed central region with a clefted opening leading to a stylar canal containing exudate produced in secretory regions. Receptivity of the non-papillate stigma is indicated by the formation of an exudate droplet, which is formed within 1 day after flower opening. Pollen viability was low to moderate; tetrad germination ranged from 20% to 40% using in vitro germination assays indicating poor pollen quality and may contribute to lack of seed development in some populations. No developmental abnormalities in stigmas or styles were observed indicating other factors are responsible for lack of sexual recruitment in the wild.

scholarly journals Viability of pollen grains and stigma receptivity in Desert Rose

2022 ◽  
Vol 28 (1) ◽  
pp. 92-98
Author(s):  
Cristiane Gonçalves Souza ◽  
Sabrina Maihave Barbosa Ramos ◽  
Silvia Nietsche ◽  
Clivia Carolina Fiorilo Possobom ◽  
Elka Fabiana Aparecida Almeida ◽  
...  
Keyword(s):  
Abiotic Factors ◽  
Pollen Viability ◽  
Oxygen Demand ◽  
Pollen Grains ◽  
Floral Biology ◽  
Effect Of Temperature ◽  
In Vitro Germination ◽  
Stigma Receptivity ◽  
Flower Opening

Abstract Adenium obesum (Forssk.) Roem. & Schult., popularly known as desert rose, has become a valuable ornamental plant. In floriculture, the production of hybrids is prioritized. Hence, knowledge on floral biology and sexual reproduction of the target species is fundamental. The objectives of this study were: (1) to test sucrose concentrations and temperatures for in vitro germination of A. obesum pollen grains; (2) to identify the effect of temperature on the viability of A. obesum pollen grains; and (3) to evaluate the viability of pollen grains and stigma receptivity in pre-anthesis, at flower opening, and 72 h post-flower opening in three accessions of A. obesum. A significant relationship between temperatures and sucrose concentrations was observed in the in vitro germination test. The highest percentage of in vitro germination of pollen grains, 39.81%, was observed at an estimated temperature of 26.05 °C. Desert rose accessions maintained in biochemical oxygen demand (BOD) chambers at 30 °C during a 16-h light photoperiod showed faster flowering, and temperatures ≥ 25 °C induced pollen grain viability percentages above 69%. Temperature is one of the most important abiotic factors, influencing mainly in pollen germination, pollen tube growing and in efficiency fertilization. The ICA-wd accession stood out and can be considered a pollen donor in artificial pollination. The stigmas of flowers were receptive from a day before flower opening until three days after. The two parameters presented above, stigma receptivity and pollen viability, allow inferences about the appropriate time for successful pollination and subsequent fertilization in desert roses.

scholarly journals Floral resource availability of Dicliptera squarrosa (Acanthaceae) and its dependence on hummingbirds for fruit formation in a forest fragment of Central Brazil

2019 ◽  
Vol 152 (1) ◽  
pp. 68-77
Author(s):  
Raphael Matias ◽  
Marco Túlio Furtado ◽  
Silvia B. Rodrigues ◽  
Hélder Consolaro
Keyword(s):  
Mating Systems ◽  
Flowering Phenology ◽  
Floral Biology ◽  
Floral Resources ◽  
Forest Fragment ◽  
Important Species ◽  
Flower Visitors ◽  
Central Brazil ◽  
Nectar Feeding ◽  
Floral Resource

Background and aims – Hummingbirds are dependent and specialized on nectar-feeding, and many plants depend upon them for pollination. However, the degree of plant-pollinator interdependence varies greatly among species; thus, information on plant mating systems and availability of resources may help to clarify the dependence of interacting organisms. The goals of this study were to (1) quantify the floral resource available during the flowering of Dicliptera squarrosa Nees for comparison with other co-flowering ornithophilous species, and to (2) determine the importance of floral visitors for the reproductive success of this plant.Methods – Data collection was performed in a forest fragment within the urban perimeter of Catalão, Goiás, from September 2012 to August 2013. We investigated the flowering phenology, floral biology, nectar characteristics, flower visitors and mating systems of D. squarrosa. Additionally, we evaluated the amount of floral resource offered (number of flowers and energy in joules) by co-flowering ornithophilous species within an area of 6000 m2 for comparison with D. squarrosa.Key results – Dicliptera squarrosa presents flowers adapted to pollination by hummingbirds, which act as the sole pollinator group for flowers of this species. Flowering occurs from June to September and is synchronous with five other co-flowering species. During the months between July and September, D. squarrosa is the main food source for hummingbirds in the area, offering more floral resources than all of the other five ornithophilous species together. Plants of this species are self-compatible, but they depend on hummingbirds to transfer pollen; levels of autonomous autogamy were low.Conclusions – We suggest that D. squarrosa is an important species for maintaining hummingbirds in the forest fragment due to its high production of nectar resources. In addition, data on floral biology, flower visitors, and mating systems showed the importance of hummingbirds for reproduction of D. squarrosa, suggesting a mutualistic interaction between plant and hummingbirds.

Floral Biology and Inefficient Pollen Removal in Banksia spinulosa var neoanglica (Proteaceae)

1991 ◽  
Vol 39 (2) ◽  
pp. 167 ◽  
Author(s):  
G Vaughton ◽  
M Ramsey
Keyword(s):  
Fruit Set ◽  
Floral Biology ◽  
Fruit Production ◽  
Pollen Deposition ◽  
Stigma Receptivity ◽  
Flower Opening ◽  
Pollen Removal ◽  
Pollen Longevity ◽  
Floral Visitors

Stigma receptivity, pollen longevity and rates of flower opening were examined in Banksia spinulosa var. neoanglica. The interaction between these aspects of floral biology and removal of self pollen by floral visitors, autogamous pollen deposition and autogamous fruit set was determined. Flowers were strongly protandrous; most stigmatic grooves opened and maximum stigma receptivity occurred 3-4 days after the flowers opened. Over 80% of pollen was viable when flowers first opened. Pollen longevity was extended; 58% and 33% of pollen was still viable 8 and 12 days respectively after the flowers opened. Rates of flower opening were slow with only 19-32 flowers opening per day, depending on temperature. More than 80% of flowers had self pollen remaining on their pollen presenters 5 days after the flowers opened. Autogamous pollination did not occur until at least 6 days after the flowers opened. Pollen deposition and fruit production were significantly less on autogamous than open-pollinated inflorescences. Pronounced protandry, extended pollen longevity and slow rates of flower opening in B. spinulosa may have been selectively favoured by inefficient removal of self pollen by floral visitors.

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