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Pollination Systems (pollination + system)
Selected AbstractsCaladium bicolor (Araceae) and Cyclocephala celata (Coleoptera, Dynastinae): A Well-Established Pollination System in the Northern Atlantic Rainforest of Pernambuco, BrazilPLANT BIOLOGY, Issue 4 2006A. 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] Pollination system of the Pilosocereus leucocephalus columnar cactus (tribe Cereeae) in eastern MexicoPLANT BIOLOGY, Issue 4 2010M. A. Munguía-Rosas Abstract It has been suggested that there is a geographic dichotomy in the pollination systems of chiropterophilous columnar cacti: in intra-tropical areas they are pollinated almost exclusively by bats, whereas in extratropical areas they are pollinated by bats, birds and bees. However, currently the studies are clumped both taxonomically (mainly Pachycereeae species) and geographically (mainly in the Tehuacan Valley and the Sonoran Desert). This clumping limits the possibility of generalising the pattern to other regions or cactus tribes. Only four of the 36 chiropterophilous cacti in Pilosocereus have been studied. Despite the tropical distribution of two Pilosocereus species, bees account for 40,100% of their fruit set. We examined how specialised is the pollination system of P. leucocephalus in eastern Mexico. As we studied tropical populations, we expected a bat-specialised pollination system. However, previous studies of Pilosocereus suggest that a generalised pollination system is also possible. We found that this cactus is mainly bat-pollinated (bats account for 33,65% of fruit set); although to a lesser degree, diurnal visitors also caused some fruit set (7,15%). Diurnal visitors were more effective in populations containing honeybee hives. P. leucocephalus is partially self-compatible (14,18% of fructification) but unable to set fruit without visitors. Despite the variation in pollination system, P. leucocephalus shows more affinity with other columnar cacti from tropical regions than with those from extratropical regions. Although we report here that a new species of tropical Pilosocereus is relatively bat-specialised, this Cereeae genus is more flexible in its pollination system than the Pachycereeae genera. [source] Evolution of obligate pollination mutualism in the tribe Phyllantheae (Phyllanthaceae)PLANT SPECIES BIOLOGY, Issue 1 2010ATSUSHI KAWAKITA Abstract The landmark discovery of obligate pollination mutualism between Glochidion plants and Epicephala moths has sparked increased interest in the pollination systems of Phyllantheae plants. In this paper I review current information on the natural history and evolutionary history of obligate pollination mutualism in Phyllantheae. Currently, an estimated >500 species are mutualistic with Epicephala moths that actively pollinate flowers and whose progeny feed on the resulting seeds. The Phyllantheae also includes species that are not mutualistic with Epicephala moths and are instead pollinated by bees and/or flies or ants. Phylogenetic analyses indicate that the mutualism evolved independently five times within Phyllantheae, whereas active pollination behavior, a key innovation in this mutualism, evolved once in Epicephala. Reversal of mutualism has occurred at least once in both partner lineages, involving a Breynia species that evolved an alternative pollination system and a derived clade of Epicephala that colonized ant-pollinated Phyllantheae hosts and thereby lost the pollinating habit. The plant,moth association is highly species specific, although a strict one-to-one assumption is not perfectly met. A comparison of plant and moth phylogenies suggests signs of parallel speciation, but partner switches have occurred repeatedly at a range of taxonomic levels. Overall, the remarkable species diversity and multiple originations of the mutualism provide excellent opportunities to address many important questions on mutualism and the coevolutionary process. Although research on the biology of the mutualism is still in its infancy, the Phyllantheae,Epicephala association holds promise as a new model system in ecology and evolutionary biology. [source] A test for Allee effects in the self-incompatible wasp-pollinated milkweed Gomphocarpus physocarpusAUSTRAL ECOLOGY, Issue 6 2009GARETH COOMBS Abstract It has been suggested that plants that are good colonizers will generally have either an ability to self-fertilize or a generalist pollination system. This prediction is based on the idea that these reproductive traits should confer resistance to Allee effects in founder populations and was tested using Gomphocarpus physocarpus (Asclepiadoideae: Apocynaceae), a species native to South Africa that is invasive in other parts of the world. We found no significant relationships between the size of G. physocarpus populations and various measures of pollination success (pollen deposition, pollen removal and pollen transfer efficiency) and fruit set. A breeding system experiment showed that plants in a South African population are genetically self-incompatible and thus obligate outcrossers. Outcrossing is further enhanced by mechanical reconfiguration of removed pollinaria before the pollinia can be deposited. Self-pollination is reduced when such reconfiguration exceeds the average duration of pollinator visits to a plant. Observations suggest that a wide variety of wasp species in the genera Belonogaster and Polistes (Vespidae) are the primary pollinators. We conclude that efficient pollination of plants in small founding populations, resulting from their generalist wasp-pollination system, contributes in part to the colonizing success of G. physocarpus. The presence of similar wasps in other parts of the world has evidently facilitated the expansion of the range of this milkweed. [source] New insights into the phylogenetics and biogeography of Arum (Araceae): unravelling its evolutionary historyBOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2010ANAHÍ ESPÍNDOLA The heat- and odour-producing genus Arum (Araceae) has interested scientists for centuries. This long-term interest has allowed a deep knowledge of some complex processes, such as the physiology and dynamics of its characteristic lure-and-trap pollination system, to be built up. However, mainly because of its large distributional range and high degree of morphological variation, species' limits and relationships are still under discussion. Today, the genus comprises 28 species subdivided into two subgenera, two sections and six subsections. In this study, the phylogeny of the genus is inferred on the basis of four plastid regions, and the evolution of several morphological characters is investigated. Our phylogenetic hypothesis is not in agreement with the current infrageneric classification of the genus and challenges the monophyly of several species. This demonstrates the need for a new infrageneric classification based on characters reflecting the evolution of this enigmatic genus. To investigate the biogeography of Arum deeply, further spatiotemporal analyses were performed, addressing the importance of the Mediterranean basin in the diversification of Arum. Our results suggest that its centre of origin was the European,Aegean region, and that major diversification happened during the last 10 Myr. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163, 14,32. [source] Lying to Pinocchio: floral deception in an orchid pollinated by long-proboscid fliesBOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2006STEVEN D. JOHNSON Plants that lack floral rewards may nevertheless attract pollinators if their flowers sufficiently resemble those of rewarding plants. Flowers of the South African terrestrial orchid Disa nervosa are similar in floral dimensions and spectral reflectance to those of a sympatric nectar-producing irid (Watsonia densiflora s.l.). Observations showed that the orchid and Watsonia share the same pollinator, a long-proboscid tabanid fly Philoliche aethiopica. These flies visited inflorescences of both species during their foraging bouts and most (64%) observed or captured on Watsonia inflorescences carried pollinaria of the orchid on their proboscides. They probe an average of 6.3 flowers on Watsonia inflorescences, but just 1.9 flowers on the Disa inflorescences, a behaviour which would strongly promote cross-pollination in the self-compatible orchid. The orchid generally achieves high levels of pollination success, with approximately 50% of flowers receiving or exporting pollen at some sites. Pollination success was also high at one site that lacked Watsonia plants, suggesting that the orchid does not have an obligate dependence on Watsonia. Its pollination system may therefore be characterized as intermediate between generalized food deception and specific floral mimicry. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society, 2006, 152, 271,278. [source] The importance of scent and nectar filters in a specialized wasp-pollination systemFUNCTIONAL ECOLOGY, Issue 5 2009Adam Shuttleworth Summary 1.,Plants with open flowers and exposed nectar should attract a wide diversity of flower visitors, yet, for reasons that are not yet well understood, some plants with these ,generalist' floral traits have highly specialized pollination systems. 2.,We investigated this problem in the African milkweed Pachycarpus grandiflorus which has open flowers that produce copious amounts of exposed and concentrated nectar, yet is visited almost exclusively by spider-hunting wasps in the genus Hemipepsis. 3.,These wasps were the only visitors found to consistently carry pollinaria and a cage experiment showed that they are capable of successfully pollinating this plant. Furthermore, experimental hand-pollinations showed that P. grandiflorus is genetically self-incompatible and thus reliant on pollinators for seed set. 4.,We investigated the roles of chemical (nectar and floral scent) and spectral properties in the selective attraction of wasps and the filtering out of other potential flower visitors. Nectar palatability experiments showed that the nectar is unpalatable to honeybees but palatable to the wasps. Choice experiments conducted in the field and using a Y-maze in the laboratory showed that wasps are attracted primarily by scent rather than visual cues. Analysis of scent using Gas Chromatography-Mass Spectrometry showed that these inflorescences produce 36 different compounds, mostly monoterpenes and aliphatics. Analysis of spectral reflectance showed that flowers have similar colouring to the background vegetation. 5.,We conclude that P. grandiflorus is specialized for pollination by Hemipepsis wasps, and in the absence of morphological filters, achieves specialization through unpalatable nectar, cryptic colouring and scent as a selective pollinator attractant. 6.,This study demonstrates that plants whose flowers are not morphologically adapted to exclude particular floral visitors can achieve specialization through non-morphological filters. [source] Diversity and abundance of insect visitors to flowers of trees and shrubs in a South African savannahAFRICAN JOURNAL OF ECOLOGY, Issue 3 2010Jonathan R. Mawdsley Abstract This study presents the results of a landscape-scale survey for insect floral visitors in the Skukuza Ranger District, Kruger National Park, South Africa. Floral visitors were sampled from flowering trees and shrubs along linear transects spanning the entire district. Six plant species were sampled in the late dry season (Acacia grandicornuta Gerstner, A. nigrescens Oliver, Cassia abbreviata Oliver, Combretum hereroense Schinz, Combretum zeyheri Sonder, Euclea divonorum Hiern), and eleven plant species were sampled during the rainy season (Acacia exuvialis Verdcourt, A. grandicornuta Gerstner, A. nilotica (L.) Willdenow, A. tortilis (Forsskal) Hayne, Dichrostachys cinerea Miquel, Flueggea virosa (Roxburgh) Baillon, Grewia bicolor Jussieu, G. flava De Candolle, G. flavescens Jussieu, G. monticola Sonder, and Peltophorum africanum Sonder). Coleoptera, Hymenoptera and Lepidoptera comprised the majority of floral visitors, while species of Blattodea, Diptera, Hemiptera and Neuroptera also occurred on flowers. Known or likely pollinators include bees (Hymenoptera: Apidae, Halictidae and Megachilidae) and scarab beetles (Coleoptera: Scarabaeidae). These plant species appear to have generalist pollination systems, with the exception of species of Grewia L., which appear to be pollinated primarily by bees. A provisional plant,pollinator food web is presented for the eleven species of trees and shrubs which flower during the rainy season. Résumé Cet article présente les résultats d'une étude, réalisée à l'échelle du paysage, des insectes qui visitent les fleurs dans le Skukuza Ranger District, dans le Parc National Kruger, en Afrique du Sud. Les insectes butineurs ont été prélevés dans des arbres et des arbustes en fleurs le long de transects linéaires qui traversent tout le district. On a échantillonné six espèces végétales en fin de saison sèche (Acacia grandicornuta Gerstner, A. nigrescens Oliver, Cassia abbreviata Oliver, Combretum hereroense Schinz, Combretum zeyheri Sonder et Euclea divonorum Hiern), et 11 pendant la saison des pluies (Acacia exuvialis Verdcourt, A. grandicornuta Gerstner, A. nilotica (L.) Willdenow, A. tortilis (Forsskal) Hayne, Dichrostachys cinerea Miquel, Flueggea virosa (Roxburgh) Baillon, Grewia bicolor Jussieu, G. flava De Candolle, G. flavescens Jussieu, G. monticola Sonder, et Peltophorum africanum Sonder). Coléoptères, hyménoptères et lépidoptères composaient la majorité des insectes qui visitaient les fleurs et l'on voyait aussi sur les fleurs des espèces de blattodées, de diptères, d'hémiptères et de neuroptères. Les pollinisateurs connus ou supposés incluent des abeilles (Hyménoptères : Apidés, Halictidés et Mégachilidés) et des scarabées (Coléoptères : Scarabéidés). Ces espèces végétales semblent avoir des systèmes de pollinisation généralistes, à l'exception d'espèces de Grewia L. qui semblent être fertilisés d'abord par les abeilles. Un réseau alimentaire provisoire plantes-pollinisateurs est présenté pour les 11 espèces d'arbres et d'arbustes qui fleurissent pendant la saison des pluies. [source] Evaluation of pollination syndromes in Antillean Gesneriaceae: evidence for bat, hummingbird and generalized flowersJOURNAL OF ECOLOGY, Issue 2 2009Silvana Martén-Rodríguez Summary 1Current views about the predominance of generalization of pollination systems have stimulated controversy concerning the validity of pollination syndromes. In order to assess the extent to which floral characters reflect selection by the most important pollinators we evaluated pollination syndromes in a florally diverse plant group, the tribe Gesnerieae, a monophyletic plant radiation from the Antillean islands. 2The study species include representatives of three groups of floral phenotypes, two of which chiefly correspond to ornithophilous and chiropterophilous syndromes. The third group includes subcampanulate flowers (characterized by a corolla constriction above the nectar chamber) with combinations of traits not fitting classic pollination syndromes. 3Pollination systems were characterized for 19 Gesnerieae species in five Antillean islands between 2003 and 2007 and supplemented with observations of four Gesneriaceae species from Costa Rica. Pollinator visitation and frequency of contact with anthers or stigmas were used to calculate an index of pollinator importance. Eleven floral traits including morphology, phenology and rewards were used to assess clustering patterns in phenotype space. 4Multidimensional scaling analysis of floral traits resulted in two clusters comprising: (i) tubular, red to yellow-flowered species with diurnal anthesis, (ii) bell-shaped-flowered species; two groups of floral phenotypes were evident within the latter cluster, campanulate nocturnal and subcampanulate flowers. Correlations between pollinator importance values and floral axes revealed strong associations with the expected pollinators, hummingbirds for tubular flowers, and bats for campanulate flowers; subcampanulate-flowered species had generalized pollination systems including bats, hummingbirds and insects. Discriminant analysis of the multivariate set of floral traits correctly classified 19 out of 23 species into the predicted pollination categories. 5Synthesis. This study provides support for classic hummingbird and bat pollination syndromes, demonstrating the importance of pollinator-mediated selection in the floral diversification of Antillean Gesnerieae. However, there was evidence for generalized pollination systems in species characterized by a unique morphological trait (corolla constriction), but with variable combinations of other floral traits. These findings suggests that floral phenotypes might also evolve under selection by various functional groups of pollinators, and underscores the importance of considering the presence and effectiveness of all floral visitors in pollination studies. [source] Speciation in the Orchidaceae: confronting the challengesMOLECULAR ECOLOGY, Issue 14 2007ROD PEAKALL The Orchidaceae is renowned for its large number of species (19 500) and its many diverse, even bizarre, specialized pollination systems. One unusual feature of orchids is the high frequency of food deception whereby animal pollination is achieved without providing nectar, pollen or other food rewards. Food-deceptive pollination is estimated to occur in approximately one-third of all orchids. Equally intriguing is pollination by sexual deception whereby pollination is achieved by the sexual attraction of male insects to the orchid flower. Sexual deception is found in several hundred species representing multiple lineages. Given their rich species diversity and extraordinary plant,animal interactions, orchids clearly offer exciting research opportunities in pollination biology, reproductive isolation and speciation, yet surprisingly they remain under-represented in scientific investigations both in these fields and more generally. In this special issue of Molecular Ecology, Moccia et al. provide an exemplar study that combine multiple lines of evidence to illuminate the mechanism of reproductive isolation between two closely related food-deceptive orchids. Their study demonstrates that many of the challenges that confront orchid researchers and impede progress in our understanding of speciation in the Orchidaceae can be overcome by the creative application and integration of both old and new tools in ecology and genetics. [source] Coping with third parties in a nursery pollination mutualism: Hadena bicruris avoids oviposition on pathogen-infected, less rewarding Silene latifoliaNEW PHYTOLOGIST, Issue 4 2006Arjen Biere Summary ,,In nursery pollination systems, pollinator offspring usually feed on pollinated fruits or seeds. Costs and benefits of the interaction for plant and pollinator, and hence its local outcome (antagonism,mutualism), can be affected by the presence of ,third-party' species. Infection of Silene latifolia plants by the fungus Microbotryum violaceum halts the development of fruits that provide shelter and food for larvae of the pollinating moth Hadena bicruris. We investigated whether the moth secures its benefit by selective oviposition on uninfected flowers. ,,Oviposition was recorded in eight natural populations as a function of plant infection status, local neighbourhood, plant and flower characteristics. ,,Oviposition was six times lower on flowers from infected than on those from uninfected plants. Oviposition decreased with decreasing flower and ovary size. Moths could use the latter to discriminate against diseased flowers. ,,Although moths show an adaptive oviposition response, they reduce the future potential of healthy hosts because they still visit infected plants for nectar, vectoring the disease, and they reduce any fitness advantage gained by disease-resistant plants through selective predation of those plants. [source] The influence of floral symmetry and pollination systems on flower size variationNORDIC JOURNAL OF BOTANY, Issue 5 2004Atushi Ushimaru We compared the amount of variation in flower size between autogamous and insect-pollinated species to examine the hypothesis that pollinator-mediated selection stabilizes flower size in plant populations. One would expect the flower size variation to be larger in selfing species that are less affected by pollinator-mediated stabilizing selection than in insect-pollinated species. The results of phylogenetic comparisons between autogamous and insect-pollinated flowers supported the pollinator-mediated stabilizing selection hypothesis, although the non-phylogenetic comparison did not. According to our results, we discuss the factors influencing the flower size variation. [source] Pollination system of the Pilosocereus leucocephalus columnar cactus (tribe Cereeae) in eastern MexicoPLANT BIOLOGY, Issue 4 2010M. A. Munguía-Rosas Abstract It has been suggested that there is a geographic dichotomy in the pollination systems of chiropterophilous columnar cacti: in intra-tropical areas they are pollinated almost exclusively by bats, whereas in extratropical areas they are pollinated by bats, birds and bees. However, currently the studies are clumped both taxonomically (mainly Pachycereeae species) and geographically (mainly in the Tehuacan Valley and the Sonoran Desert). This clumping limits the possibility of generalising the pattern to other regions or cactus tribes. Only four of the 36 chiropterophilous cacti in Pilosocereus have been studied. Despite the tropical distribution of two Pilosocereus species, bees account for 40,100% of their fruit set. We examined how specialised is the pollination system of P. leucocephalus in eastern Mexico. As we studied tropical populations, we expected a bat-specialised pollination system. However, previous studies of Pilosocereus suggest that a generalised pollination system is also possible. We found that this cactus is mainly bat-pollinated (bats account for 33,65% of fruit set); although to a lesser degree, diurnal visitors also caused some fruit set (7,15%). Diurnal visitors were more effective in populations containing honeybee hives. P. leucocephalus is partially self-compatible (14,18% of fructification) but unable to set fruit without visitors. Despite the variation in pollination system, P. leucocephalus shows more affinity with other columnar cacti from tropical regions than with those from extratropical regions. Although we report here that a new species of tropical Pilosocereus is relatively bat-specialised, this Cereeae genus is more flexible in its pollination system than the Pachycereeae genera. [source] Evolution of obligate pollination mutualism in the tribe Phyllantheae (Phyllanthaceae)PLANT SPECIES BIOLOGY, Issue 1 2010ATSUSHI KAWAKITA Abstract The landmark discovery of obligate pollination mutualism between Glochidion plants and Epicephala moths has sparked increased interest in the pollination systems of Phyllantheae plants. In this paper I review current information on the natural history and evolutionary history of obligate pollination mutualism in Phyllantheae. Currently, an estimated >500 species are mutualistic with Epicephala moths that actively pollinate flowers and whose progeny feed on the resulting seeds. The Phyllantheae also includes species that are not mutualistic with Epicephala moths and are instead pollinated by bees and/or flies or ants. Phylogenetic analyses indicate that the mutualism evolved independently five times within Phyllantheae, whereas active pollination behavior, a key innovation in this mutualism, evolved once in Epicephala. Reversal of mutualism has occurred at least once in both partner lineages, involving a Breynia species that evolved an alternative pollination system and a derived clade of Epicephala that colonized ant-pollinated Phyllantheae hosts and thereby lost the pollinating habit. The plant,moth association is highly species specific, although a strict one-to-one assumption is not perfectly met. A comparison of plant and moth phylogenies suggests signs of parallel speciation, but partner switches have occurred repeatedly at a range of taxonomic levels. Overall, the remarkable species diversity and multiple originations of the mutualism provide excellent opportunities to address many important questions on mutualism and the coevolutionary process. Although research on the biology of the mutualism is still in its infancy, the Phyllantheae,Epicephala association holds promise as a new model system in ecology and evolutionary biology. [source] Contribution of small insects to pollination of common buckwheat, a distylous cropANNALS OF APPLIED BIOLOGY, Issue 1 2009Hisatomo Taki Abstract Crop pollination by animals is an essential ecosystem service. Among animal-pollinated crops, distylous plants strongly depend on animal pollination. In distylous pollination systems, pollinator species are usually limited, although flowers of some distylous plants are visited by diverse animals. We studied the pollination biology of common buckwheat (Fagopyrum esculentum), a distylous crop mainly pollinated by honeybees and visited by many insect species, to evaluate the effects of non-honeybee species on pollination services. We focused on insects smaller than honeybees to determine their contribution to pollination. We applied pollination treatments with bags of coarse mesh to exclude flower visits by honeybees and larger insects and compared the seed set of bagged plants with that of untreated plants for pin and thrum flower morphs. We found a great reduction of seed set only in bagged pin flowers. We also confirmed that small insects, including ants, bees, wasps and flies, carried pin-morph pollen. These small insects transfer pollen from the short anthers of pin flowers to the short styles of thrum flowers, leading to sufficient seed set in thrum flowers. Consequently, small, non-honeybee insects have the potential to maintain at least half of the yield of this honeybee-dependent distylous crop. [source] Flower visitors and pollination in the Oriental (Indomalayan) RegionBIOLOGICAL REVIEWS, Issue 3 2004Richard T. Corlett ABSTRACT Current knowledge of flower visitors and pollination in the Oriental Region is summarised. Much less is known about pollination than seed dispersal and the coverage of habitats and taxa in the region is very uneven. The available evidence suggests that pollination in lowland forests is dominated by highly social bees (mainly Trigona and Apis species), with beetles probably the next most important group, followed by other bees and flies. In comparison with the better-studied Neotropics, large solitary bees, moths, Lepidoptera and vertebrates are relatively less important. These differences are greatest in the canopy of the lowland dipterocarp forests of Southeast Asia, where they probably reflect the unique temporal pattern of floral resource availability resulting from,general flowering'at supra-annual intervals. Apis bees (but not Trigona species) are also important in most montane, subtropical and non-forest habitats. Apart from the figs (Ficus spp.), there are few well-documented examples of plant species visited by a single potential pollinator and most plant-pollinator relationships in the region appear to be relatively generalised. The small sizes of most pollinators and the absence of direct human exploitation probably make pollination mutualisms less vulnerable to failure as a result of human impacts than dispersal mutualisms, but more subtle impacts, as a result of altered gene flows, are likely to be widespread. On current evidence, pollination systems in the Oriental Region do not require any specific conservation action, but this review reinforces arguments for making the preservation (or restoration) of habitat connectivity the major focus of Oriental conservation. [source] | ||||||||||||||||||||||