scholarly journals Morphofunctional Traits and Pollination Mechanisms ofCoronilla emerusL. Flowers (Fabaceae)

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Giovanna Aronne ◽  
Manuela Giovanetti ◽  
Veronica De Micco
Keyword(s):  
Selective Pressure ◽  
Pollen Viability ◽  
Pollination Efficiency ◽  
Pollen Transfer ◽  
Stigma Receptivity ◽  
Pollination Mechanisms ◽  
Hand Pollination ◽  
And Function ◽  
Different Parts ◽  
Floral Larceny

It is accepted that the papilionaceous corolla of the Fabaceae evolved under the selective pressure of bee pollinators. Morphology and function of different parts ofCoronilla emerusL. flowers were related to their role in the pollination mechanism. The corolla has a vexillum with red nectar lines, a keel hiding stamens and pistil, and two wing petals fasten to the keel with two notched folds. Pollinators land on the complex of keel and wings, trigger the protrusion of pollen and finally of the stigma from the keel tip. Data on pollen viability and stigma receptivity prove that flowers are proterandrous. The results of hand-pollination experiments confirmed that insects are fundamental to set seed. Interaction with pollinators allows not only the transport of pollen but also the rupture of the stigmatic cuticle, necessary to achieve both allogamy and autogamy. Field observations showed that Hymenoptera, Lepidoptera, and Diptera visited the flowers. Only some of the Hymenoptera landed on the flowers from the front and elicited pollination mechanisms. Most of the insects sucked the nectar from the back without any pollen transfer. Finally, morphological and functional characteristics ofC. emerusflowers are discussed in terms of floral larceny and reduction in pollination efficiency.

scholarly journals Pollen viability and stigma receptivity in Swainsona formosa (G.Don) J.Thompson (Fabaceae), an ornamental legume native to Australia

2019 ◽  
Vol 25 (2) ◽  
pp. 158-167
Author(s):  
Zulkarnain Zulkarnain ◽  
Eliyanti Eliyanti ◽  
Elly Indra Swari
Keyword(s):  
Pollen Viability ◽  
Pollen Grains ◽  
Storage Conditions ◽  
Total Darkness ◽  
Anther Dehiscence ◽  
Stigma Receptivity ◽  
Cross Pollination ◽  
Hand Pollination ◽  
Dry Conditions

Pollen viability and stigma receptivity are prerequisites for successful cross-pollination and seed set in Swainsona formosa. In this study, the pollen viabilities and stigma receptivities was assayed by in vitro pollen germination and simple hand-pollination method on glasshouse-grown plants, respectively. The viability of pollen grains was tested under three different storage conditions: 1) pollen grains were left on the plant in the glasshouse under natural conditions, 2) pollen grains were harvested and kept at a low temperature (4 o C) in total darkness, and 3) pollen grains were kept in a dry freezer (-10 o C) and in total darkness. Meanwhile, stigma receptivity was determined by hand-pollination using fresh pollen grains on flower of glasshouse-grown plants at one day before anther dehiscence up to 8 days after anther dehiscence. The results showed that pollen grains could be stored at 4 o C for up to 28 days without significantly losing their viability. Pollen longevity could be extended beyond two months when stored at -10 o C and under dry conditions. These findings provided a simple and economically sound method for storage of S. formosa pollen. In addition, stigma receptivity was found to be receptive from one day before anther dehiscence and reached its peak within four days after anther dehiscence. These results provide a valuable background to the conventional breeding of this species to create hybrids through cross-pollination

scholarly journals Is the pollination efficiency of long-lived orchid flowers affected by age?

Revista CERES ◽  
2015 ◽  
Vol 62 (4) ◽  
pp. 347-350
Author(s):  
Rúbia Santos Fonseca ◽  
Flávia Aparecida dos Santos ◽  
Milene Faria Vieira
Keyword(s):  
Hydrogen Peroxide ◽  
Reproductive Success ◽  
Maximum Degree ◽  
Fruit Set ◽  
Pollination Efficiency ◽  
Stigma Receptivity ◽  
Orchid Species ◽  
Hand Pollination ◽  
Flower Age

The long-lived flowers of orchids increase the chances of pollination and thus the reproductive success of the species. However, a question arises: does the efficiency of pollination, expressed by fruit set, vary with the flower age? The objective of this study was to verify whether the flower age of Corymborkis flava(Sw.) Kuntze affects pollination efficiency. The following hypotheses were tested: 1) the fruit set of older flowers is lower than that of younger ones; 2) morphological observations (perianth and stigmatic area), stigma receptivity test by using a solution of hydrogen peroxide and hand-pollination tests are equally effective in defining the period of stigmatic receptivity. Flowers were found to be receptive from the first to the fourth day of anthesis. Fruit set of older flowers (third and fourth day) was lower than that of younger flowers. Morphological observations, the stigma receptivity test and hand-pollinations were equally effective in defining the period of stigmatic receptivity. However, to evaluate the maximum degree of stigma receptivity of orchid species with long-lived flowers, we recommend hand-pollinations, beyond the period of receptivity.

scholarly journals Rubus glaucus Benth.: morphology and floral biology aimed at plant breeding processes

2019 ◽  
Vol 72 (3) ◽  
pp. 8909-8915
Author(s):  
Ana María López Gutiérrez ◽  
Marta Leonor Marulanda Angel ◽  
Lina María Gómez López ◽  
Carlos Felipe Barrera Sánchez
Keyword(s):  
Plant Breeding ◽  
Pollen Viability ◽  
Morphological Characteristics ◽  
Qualitative Evaluation ◽  
Floral Biology ◽  
Stigma Receptivity ◽  
Mountain Ranges ◽  
Sexual Hybridization ◽  
Planting Material ◽  
Pollination Mechanisms

Rubus glaucus is widely distributed throughout the three mountain ranges of Colombia, where the blackberry growers have highlighted the need to standardize the supply of planting material, starting with plant breeding schemes that lead to more productive varieties with morphological characteristics that ease agricultural activities. Plant breeding activities have improved by considering the pollination mechanisms of plants. The implementation of controlled sexual hybridization depends on these pollination mechanisms, and several plant breeding methods have been adapted to crop pollination patterns. Morphological characteristics and studies on the floral biology of R. glaucus Benth were conducted to improve plant breeding processes. In addition, a study on pollen viability and stigma receptivity were performed. The reported morphological characteristics of R. glaucus enabled characterization of its flowers as complete and perfect with a regular, actinomorphic, perianth heterochlamydeous, dialipetalous, and dialisepalous structure. Meanwhile, the evaluation of different collection times for pollen viability revealed significant differences. The highest pollen viability occurred at 10:00 am, followed by 9:00 am. Qualitative evaluation of stigma receptivity led to the conclusion that the highest stigma receptivity is at anthesis at 12:00 m.

Pollen Storage and Breeding System in Relation to Controlled Pollination of Four Species of Acacia (Leguminosae: Mimosoideae)

1993 ◽  
Vol 41 (5) ◽  
pp. 601 ◽  
Author(s):  
M Sedgley ◽  
J Harbard
Keyword(s):  
Pollen Viability ◽  
Anther Dehiscence ◽  
Triphenyltetrazolium Chloride ◽  
Pollen Storage ◽  
Stigma Receptivity ◽  
African Species ◽  
Hand Pollination ◽  
Staining Methods ◽  
One Year

Pollen of A. auriculiformis, A. iteaphylla, A. karroo and A. mangium was stored at 25, 5, -18 or -196°C for up to 3 years, and its viability tested by pollen staining, in vivo pollen tube growth or pod set 1 month after hand pollination. The effectiveness of staining methods using 2,3,5-triphenyltetrazolium chloride (TTC), 5-bromo-4-chloro-3-indole- β -galactoside (X-Gal) and fluorescein diacetate (FDA) to predict pollen viability was investigated. All of the staining methods gave variable results, but the TTC and X-Gal tests were particularly unreliable. FDA staining of pollen gave the best indication of its ability to germinate on the stigma and penetrate ovules. Pollen stored for up to three days at 25°C retained the ability to penetrate ovules following hand pollination, and of that stored for three years at 5°C, 19% of the grains fluoresced with FDA. Pollen stored at -18°C for 1 year retained the ability to penetrate ovules and produce pod set, and of that stored for 3 years, 23% of the grains fluoresced with FDA. Pollen stored at -196°C for one year retained the ability to penetrate ovules and produce pod set, but thawing and refreezing of the pollen reduced viability to zero. It was concluded that the most successful and convenient method of pollen storage was vaccuum drying followed by storage at -18°C. The Australian species of Acacia investigated (A. iteaphylla, A. auriculiformis and A. mangium) had protogynous flowers, with stigma receptivity preceding anther dehiscence, such that flowers could be reliably hand pollinated. The African species A. karroo had protandrous flowers, with stigmas unreceptive at anthesis, but receptive at 5 days after anther dehiscence. Deposition of self pollen on the stigma prior to attainment of receptivity rendered hand pollination of this species unreliable.

scholarly journals Secondary pollen presentation and foral traits of Heliconia psittacorum

2018 ◽  
Vol 24 (4) ◽  
pp. 451-458
Author(s):  
Talita Oliveira Nascimento ◽  
Patricia Campos Silva ◽  
Vivian Loges ◽  
Sandra Mariotto ◽  
Willian Krause ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Temporal Dynamics ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Pollen Deposition ◽  
Pollen Transfer ◽  
Stigma Receptivity ◽  
Secondary Pollen Presentation ◽  
Self Pollination ◽  
Pollen Presentation

The secondary presentation of pollen consists of a foral mechanism where the presentation of pollen occurs in other foral structures in addition to the anther, in order to increase the precision of the dispersion of the pollen by the vectors. This study aims to describe the temporal dynamics of secondary pollen presentation, and morphological and morphometric characteristics in stages of pre- anthesis and anthesis in genotypes of fve natural Heliconia psittacorum populations. For the study of foral morphometry traits of length of the fower, stamen, stigma and height of flament insertion in the petal in bud and fower were measured. The foral morphology of pre-anthesis buds and fowers in anthesis, the presence or absence of characteristics such as herkogamy, region of flament insertion in the petal, region of stylar hairs, and of secondary pollen deposition were evaluated. Treatments of controlled pollinations, self-pollination, geitonogamy, cross-pollination, natural pollination and growth to pollen tube were sampled. Floral herkogamy and pollen transfer to the adhered hairs in the stylar region were clearly observed during anthesis, constituting the frst record of occurrence of secondary pollen presentation in Heliconiaceae. Pollen tube growth was inhibited in the stigmatic, style and basal regions of the pistil. Natural fruiting produced little or no fruit. The positioning of the stamens above the stigma, pollen viability and stigma receptivity during anthesis of H. psittacorum fowers may favor self-pollination. The stylar hairs observed in all H. psittacorum populations’ help in the retention of pollen grains. The low fruiting rate in controlled and natural pollinations suggest that the main propagation form of H. psittacorum in the study areas is based on asexual reproduction.

Pollen scavenging and rain involvement in the pollination mechanism of interior spruce

1996 ◽  
Vol 74 (1) ◽  
pp. 115-124 ◽  
Author(s):  
C. John Runions ◽  
John N. Owens
Keyword(s):  
Picea Glauca ◽  
Selective Pressure ◽  
Seed Orchard ◽  
Picea Engelmannii ◽  
Pollination Efficiency ◽  
Pollination Mechanism ◽  
Pollination Mechanisms ◽  
Seed Cone ◽  
Interior Spruce ◽  
Pollination Drop

Pollination drops are secreted from the ovules of interior spruce (Picea glauca or Picea engelmannii and their hybrid) as seed cones begin to close at the end of the pollination period. Secreted pollination drops persist within spaces surrounding the micropylar opening in closed seed cones. Saccate pollen floats into the micropyle within the pollination drop. Pollination drops become voluminous enough, within the enclosed spaces, to scavenge pollen adhering to the micropylar arms and other surfaces in proximity with the micropyle. Scavenging of pollen from cone surfaces adjacent to the integuments is sometimes facilitated by rainwater that can float pollen into the opening of the micropyle before cone closure and pollination drop secretion. In practice, periodic, light misting of seed orchard trees during seed cone receptivity might increase pollination efficiency by mimicking rainwater involvement in the pollination mechanism. Rainwater involvement in pollination of some modern conifers may reflect a similar situation in the pollination mechanisms of ancestral conifers. Environments with limited rainfall combined with the requirement for moisture in the pollination mechanism may have provided the selective pressure for evolution of the pollination drop. Keywords: pollination drop, Picea, conifer, sacci.

scholarly journals Nocturnal and diurnal pollination in Copaifera coriacea, a dominant species in sand dunes of the Middle São Francisco River Basin, Northeastern Brazil

2021 ◽  
Vol 154 (2) ◽  
pp. 207-216
Author(s):  
Isys Mascarenhas Souza ◽  
Frederic Mendes Hughes ◽  
Ligia Silveira Funch ◽  
Luciano Paganucci de Queiroz
Keyword(s):  
Uv Light ◽  
Pollen Viability ◽  
Sand Dunes ◽  
Abundant Species ◽  
Pollen Tubes ◽  
Northeastern Brazil ◽  
Stigma Receptivity ◽  
Flower Opening ◽  
Pollination System ◽  
Floral Visitors

Background and aims – Copaifera coriacea, a species in the resin-producing clade Detarioideae (Leguminosae), is an endemic and abundant species found in sand dunes in Brazilian Caatinga domain vegetation – a Quaternary paleodesert. We investigated floral traits and aspects of pollination biology, focusing on the pollination system of C. coriacea. Material and methods – Anthesis duration, stigma receptivity, pollen viability, nectar concentration, and the presence of osmophores and pigments reflecting UV light were assessed. Floral visitors were classified as potential pollinators, occasional pollinators or thieves, based on the time and foraging behaviour and resource collected. Pollination effectiveness were assessed for potential pollinators by the detection of pollen tubes on the stigma or stylar canal by epifluorescence microscopy.Key results – The species has white and small flowers, with anthesis beginning in the dark (ca 00:30) and the flowers are completely opened approximately 3 h later, when a sweet odour is perceptible. The onset of stigma receptivity and pollen grain viability occurs only after the completion of flower opening, and a concentrated nectar is available during the day. The presence of pollen tubes confirmed the efficiency of the main insects in the transfer of pollen. Conclusion – Our result demonstrates that C. coriacea has a generalist pollination system mediated mainly by two distinct guilds of insect pollinators: moths (nocturnal, searching for nectar) and bees (diurnal, pollen collectors). This finding can provide more information about diversification in the genus Copaifera.

scholarly journals Butterfly-wing pollination in Scadoxus and other South African Amaryllidaceae

2020 ◽  
Vol 193 (3) ◽  
pp. 363-374 ◽  
Author(s):  
Hannah C Butler ◽  
Steven D Johnson
Keyword(s):  
South African ◽  
Ventral Surface ◽  
Butterfly Wing ◽  
Pollen Transfer ◽  
Floral Structure ◽  
Pollination Mechanisms ◽  
Butterfly Wings ◽  
Floral Diversification ◽  
Swallowtail Butterflies ◽  
Transfer Mechanisms

Abstract Understanding the evolution of floral morphology requires information about the identity of pollinators as well as the specific mechanisms of pollen transfer. Based on preliminary field observations and floral structure, we hypothesized that pollination mechanisms involving the transfer of pollen on butterfly wings occur in several lineages of South African Amaryllidaceae. Here we report findings from a detailed study of butterfly-wing pollination in two subspecies of Scadoxus multiflorus and review the prevalence of this pollination mechanism among other Amaryllidaceae in southern Africa. We established that S. multiflorus subsp. katherinae is genetically self-incompatible and thus entirely reliant on pollinators for seed production. We determined that this subspecies is pollinated almost exclusively by large swallowtail butterflies, principally males of the mocker swallowtail Papilio dardanus cenea. Flowers of S. multiflorus subsp. multiflorus are pollinated by pierid and swallowtail butterflies. Pollen is deposited on the ventral surface of the wings of butterflies as they flutter over the strongly exserted stamens. We predict that butterfly-wing pollination occurs in at least nine species of South African Amaryllidaceae, which may reflect several independent origins of this mechanism. The flowers of these species are red or orange with strong herkogamy and are either bowl-brush or open-brush in shape. We provide maps of the distribution of pollen on the ventral surface of the wings of pollinators for four of these species. All four appear to be pollinated via the ventral surface of large butterfly wings, with the floral structure facilitating the process. These findings illustrate the importance of investigating pollen transfer mechanisms in order to understand patterns of floral diversification and floral convergence.

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