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Pollination Ecology (pollination + ecology)

Distribution by Scientific Domains

Life Sciences	100%

Selected Abstracts

Pollination ecology of Isoglossa woodii, a long-lived, synchronously monocarpic herb from coastal forests in South Africa

PLANT BIOLOGY, Issue 3 2010
M. E. Griffiths
Abstract Synchronous monocarpy in long-lived plants is often associated with pollination by wind, in part because infrequent mass flowering may satiate pollinators. Selfing in synchronous monocarps may provide reproductive assurance but conflict with the benefits of outcrossing, a key evolutionary driver of synchrony. We predicted that animal-pollinated species with synchronous flowering would have unspecialised flowers and attract abundant generalised pollinators, but predictions for selfing and outcrossing frequencies were not obvious. We examined the pollination biology of Isoglossa woodii (Acanthaceae), an insect-pollinated, monocarpic herb that flowers synchronously at 4,7-year intervals. The most frequent visitor to I. woodii flowers was the African honeybee, Apis mellifera adansonii. Hand-pollination failed to enhance seed production, indicating that the pollinators were not saturated. No seed was set in the absence of pollinators. Seed set was similar among selfed and outcrossed flowers, demonstrating a geitonogamous mixed-mating strategy with no direct evidence of preferential outcrossing. Flowers contained four ovules, but most fruits only developed one seed, raising the possibility that preferential outcrossing occurs by post-pollination processes. We argue that a number of the theoretical concerns about geitonogamous selfing as a form of reproductive assurance do not apply to a long-lived synchronous monocarp such as I. woodii. [source]

Pollination ecology, genetic diversity and selection on nectar spur length in Platanthera lacera (Orchidaceae)

PLANT SPECIES BIOLOGY, Issue 3 2005
KAREN J. LITTLE
Abstract Platanthera lacera (Orchidaceae) is a moth-pollinated, loess prairie orchid producing a raceme of one to many whitish-green flowers. Field studies on a western Illinois population found the crepuscular visiting noctuid moth, Anagrapha falcifera (Noctuidae), to be the most frequent pollinator with occasional visits from Allagrapha aerea (Noctuidae). Visitation rates, assessed by removal of at least one pollinium, were relatively high (84.9%) and fruit production on experimentally outcrossed flowers (94.4%) was higher than open-pollinated plants (71.4%). Experimental pollination showed P. lacera to be highly self-compatible (94.1%) with a low level of autogamy (8.2%). Measurements taken from 598 spurs on 44 plants indicated that nectar spur length varied significantly among plants (10.9,17.1 mm, mean 14.3 mm), but was not under selective pressure from visitation by An. falcifera (mean proboscis length 11.1 mm). The absence of selective pressure on nectar spur length is likely to be explained by occasional pollinating visits from Al. aerea (proboscis length 18 mm) and a limited amount of autogamy. Electrophoretic analysis of 12 enzymes revealed seven polymorphic loci. Mean levels of heterozygosity were He = 0.3384, Ho = 0.3229 and F = 0.0458, indicating that P. lacera is primarily an outcrossing species dependent on noctuid moth pollination. [source]

Factors affecting pollination ecology of Quercus anemophilous species in north-west Spain

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2005
F. J. RODRÍGUEZ-RAJO
Pollination ecology of Quercus is influenced by meteorological, biotic and genetic factors. This study was undertaken to ascertain the effect induced by these factors on pollen production, release and dispersion. Aerobiological data have been used in recent years as phenological information, because the presence of pollen in the air is the result of flowering across a wide area. The onset of the Quercus pollen season and the atmospheric pollen concentrations during the pollination period in two localities of north-west Spain (Ourense and Santiago) were determined from 1993 to 2001. There were important variations in total annual pollen as a result of meteorological conditions, lenticular galls produced by Neuropterus on catkins and biennial genetic rhythms of pollen production. In order to determine the beginning of flowering, a thermal time model has been used. Chill requirements were around 800 chilling hours (CH) and heat requirements were 953 growth degree days (GDD in °C) in Santiago and 586 GDD in Ourense. Pollen in the air show positive correlation (99% significance) with daily thermal oscillation, maximum and minimum temperatures, and hours of sunshine. Regression analysis with previous days' pollen concentrations explained the high percentage of pollen concentration variability, as meteorological variables do not, on their own, explain pollen production and release. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 149, 283,297. [source]

GUEST EDITORIAL: The interplay of pollinator diversity, pollination services and landscape change

JOURNAL OF APPLIED ECOLOGY, Issue 3 2008
Ingolf Steffan-Dewenter
Summary 1Pollinators are a functional group with high relevance for ensuring cross-pollination in wild plant populations and yields in major crops. Both pollinator declines and losses of pollination services have been identified in the context of habitat destruction and land use intensification. 2This editorial synthesizes and links the findings presented in seven papers in this Special Profile, focusing on pollinator diversity and plant,pollinator interactions in natural habitats and agricultural landscapes. 3The results contribute to our understanding of local and landscape scale effects of land use intensification on pollinator densities and diversity, and pollination functions in wild plant communities and crops. 4Synthesis and applications. We emphasize the exceptional coverage in pollination ecology ranging from basic ecological relationships to applied aspects of ecosystem services and ecosystem management, and conclude with identifying gaps in current knowledge and challenging research areas for the future. [source]

Caladium bicolor (Araceae) and Cyclocephala celata (Coleoptera, Dynastinae): A Well-Established Pollination System in the Northern Atlantic Rainforest of Pernambuco, Brazil

PLANT BIOLOGY, Issue 4 2006
A. C. D. Maia
Abstract: Flowering, pollination ecology, and floral thermogenesis of Caladium bicolor were studied in the Atlantic Rainforest of Pernambuco, NE Brazil. Inflorescences of this species are adapted to the characteristic pollination syndrome performed by Cyclocephalini beetles. They bear nutritious rewards inside well-developed floral chambers and exhibit a thermogenic cycle which is synchronized to the activity period of visiting beetles. Heating intervals of the spadix were observed during consecutive evenings corresponding to the beginning of the female and male phases of anthesis. Highest temperatures were recorded during the longer-lasting female phase. An intense sweet odour was volatized on both evenings. Beetles of a single species, Cyclocephala celata, were attracted to odoriferous inflorescences of C. bicolor and are reported for the first time as Araceae visitors. All the inflorescences visited by C. celata developed into infructescences, whereas unvisited inflorescences showed no fruit development. Findings of previous studies in the Amazon basin of Surinam indicated that Cyclocephala rustica is a likely pollinator of C. bicolor. This leads to the assumption that locally abundant Cyclocephalini species are involved in the pollination of this species. [source]

Reproductive biology and pollination ecology of the rare Yellowstone Park endemic Abronia ammophila (Nyctaginaceae)

PLANT SPECIES BIOLOGY, Issue 2 2006
N. ELIZABETH SAUNDERS
Abstract We examined the breeding system, reproductive output and pollination ecology of Abronia ammophila Greene, a rare and highly restricted endemic of Yellowstone National Park, Wyoming, USA. Floral morphology permits the automatic deposition of self-pollen on the stigma of individual flowers, and male and female reproductive functions temporally overlap. In controlled hand-pollination treatments, we found no significant difference among pollination treatments (unmanipulated, self-pollinated or cross-pollination). The species maintains a long reproductive season with high reproductive output (natural seed set ranged from 59 to 84%). Our results, along with pollinator observations, suggest that A. ammophila exhibits a mixed-mating system: the species can produce seed without pollinators (via either autogamy or agamospermy), but is also visited by an array of pollinating insects that included moths, butterflies and bumblebees. However, noctuid moths were the most abundant pollinators. In contrast, other Abronia species are obligate outcrossers. The mixed-mating system of A. ammophila may have evolved as a consequence of ecological pressures such as scarcity of mates or pollinators. [source]

Invasive Africanized honey bee impact on native solitary bees: a pollen resource and trap nest analysis

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009
DAVID W. ROUBIK
Little is known of the potential coevolution of flowers and bees in changing, biodiverse environments. Female solitary bees, megachilids and Centris, and their nest pollen provisions were monitored with trap nests over a 17-year period in a tropical Mexican biosphere reserve. Invasion by feral Apis (i.e. Africanized honey bees) occurred after the study began, and major droughts and hurricanes occurred throughout. Honey bee competition, and ostensibly pollination of native plants, caused changes in local pollination ecology. Shifts in floral hosts by native bees were common and driven by plant phylogenetics, whereby plants of the same families or higher taxa were substituted for those dominated by honey bees or lost as a result of natural processes. Two important plant families, Anacardiaceae and Euphorbiaceae, were lost to competing honey bees, but compensated for by greater use of Fabaceae, Rubiaceae, and Sapotaceae among native bees. Natural disasters made a large negative impact on native bee populations, but the sustained presence of Africanized honey bees did not. Over 171 plant species comprised the pollen diets of the honey bees, including those most important to Centris and megachilids (72 and 28 species, respectively). Honey bee pollination of Pouteria (Sapotaceae) plausibly augmented the native bees' primary pollen resource and prevented their decline. Invasive generalist pollinators may, however, cause specialized competitors to fail, especially in less biodiverse environments. No claim to original US government works. Journal compilation © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 152,160. [source]

Factors affecting pollination ecology of Quercus anemophilous species in north-west Spain

Reproductive biology of Boswellia serrata, the source of salai guggul, an important gum-resin

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2005
V. G. SUNNICHAN
Detailed studies were carried out on the phenology, floral biology, pollination ecology and breeding system of Boswellia serrata Roxb. (Burseraceae) the source of ,salai guggul'. The trees remain leafless during the entire period of flowering and fruiting. The inflorescence is a terminal raceme and produces up to 90 bisexual, actinomorphic flowers. On average a flower produces 10 044 ± 1259 starch-filled pollen grains. About 85% of the fresh pollen grains are viable; the pollen to ovule ratio is 3348 : 1. The stigma is of the wet papillate type. The style is hollow with three flattened stylar canals filled with a secretion product. The stylar canals are bordered by a layer of glandular canal cells. The inner tangential wall of the canal cells shows cellulose thickenings. The ovary is trilocular and bears three ovules, one in each locule. Flowers offer nectar and pollen as rewards to floral visitors. The giant Asian honey bee (Apis dorsata) and A. cerana var. indica(Indian honey bee) are the effective pollinators. The species is self-incompatible and the selfed pollen tubes are inhibited soon after their entry into the stigma. Self-pollen tubes develop a characteristic ,isthmus' as a result of enlargement of the tube soon after emergence through the narrow germ pore. Cross-pollinated flowers allowed normal pollen germination and pollen tube growth, and resulted in fruit- and seed-set. Under open pollination fruit-set was only about 10%. Although manual cross-pollinations increased fruit set, it was only up to about 20%. Low fruit set appears to be the result of inadequate cross-pollination and other constraints, presumably limitation of available nutrients. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 147, 73,82. [source]