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.

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 Breeding biology and distyly in Palicourea rigida H. B. & K. (Rubiaceae) in the Cerrados of Central Brazil

2010 ◽  
Vol 24 (3) ◽  
pp. 686-696 ◽  
Author(s):  
Adriana de Oliveira Machado ◽  
Ana Palmira Silva ◽  
Helder Consolaro ◽  
Mariluza A. Granja e Barros ◽  
Paulo Eugênio Oliveira
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Pollen Grains ◽  
Floral Biology ◽  
Nectar Production ◽  
Central Brazil ◽  
Palicourea Rigida ◽  
Floral Visitors ◽  
Compatible Pollen ◽  
Incompatibility Reactions

Distyly is a floral polymorphism more common among the Rubiaceae than in any other angiosperm group. Palicourea rigida is a typically distylous species of the Rubiaceae widely distributed in the Brazilian Cerrados. This work aimed to study the floral biology and breeding system of P. rigida in order to verify if there wasasymmetry between floral morphs. The work was carried out at Fazenda Água Limpa, Brasília-DF, from 1993 to 1995; and at Serra Caldas Novas State Park-Goias and in Clube Caça e Pesca Itororó de Uberlândia-Minas Gerais in 2005 and 2006. Density, height and pin/thrum ratio were assessed for flowering individuals in all areas. Plants were investigated for differences in floral morphology, nectar production, reproductive success and site of self incompatibility reactions. Blooming period was long and concentrated during the rains. Flowers were clearly distylous and with reciprocal herkogamy. They produced nectar and lasted for a single day. In spite of differences in density and height, populations were mostly isoplethic. Nectar production varied in volume and concentration but the differences could not be associated with floral morphs. The species is self-incompatible but reproductive success was always high and independent of floral morphs. There were differences in the site of incompatibility barriers between floral morphs, which were similar to those observed for other Rubiaceae. The main floral visitors and pollinators were the hummingbirds Colibri serrirostris and Eupetomena macroura. High fruit-set indicates that the pollinators transported enough compatible pollen grains between floral morphs, despite their territorial behavior.

Staminodes influence pollen removal and deposition rates in nectar-rewarding self-incompatible Phanera yunnanensis (Caesalpinioideae)

2019 ◽  
Vol 35 (1) ◽  
pp. 34-42
Author(s):  
Menglin Wang ◽  
Shuyin Huang ◽  
Manru Li ◽  
Doyle McKey ◽  
Ling Zhang
Keyword(s):  
Fruit Set ◽  
Removal Rate ◽  
Apis Cerana ◽  
Pollen Dispersal ◽  
Adaptive Significance ◽  
Western China ◽  
Pollen Deposition ◽  
Deposition Rates ◽  
Flower Visitation ◽  
Pollen Removal

AbstractStaminodes are sterile stamens that produce no pollen, exhibit diverse structures and perform various functions. Flowers of Phanera yunnanensis possess three fertile stamens with large anthers and long filaments, and seven staminodes with tiny anthers and short filaments. To investigate the adaptive significance of staminodes in this species, we studied effects of staminode removal on pollen removal and deposition, flower visitation rate and fruit set in Xishuangbanna, south-western China. Four species of nectar-foraging pollinators visited flowers, mostly Amegilla zonata and Apis cerana (2.80 ± 0.15 and 1.76 ± 0.41 visits h−1 per flower, respectively). Staminode removal did not affect fruit set, but increased visitation by A. cerana by 2.6-fold, reduced visitation by A. zonata by 68% and increased the pollen removal rate for both pollinators (all effects were significant). Staminode removal significantly reduced pollen deposition rate for A. zonata, but not for A. cerana. These results suggest that the staminodes of P. yunnanensis filter which insects act as pollinators and affect pollen removal and deposition rates. By reducing pollen removal rates, staminodes may implement a pollen-dispensing schedule that spreads pollen dispersal from individual flowers over multiple pollinators. By altering pollen deposition rates, staminodes may influence reproductive fitness in other ways.

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.

Flowering pattern and fruit production in the dioecious shrub Oemleria cerasiformis (Rosaceae)

1986 ◽  
Vol 64 (6) ◽  
pp. 1216-1220 ◽  
Author(s):  
Geraldine A. Allen
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Fruit Production ◽  
Flowering Period ◽  
Flowering Pattern ◽  
Flower Opening ◽  
Inflorescence Size ◽  
Hand Pollination ◽  
Flower Display ◽  
Female Flowers

Male plants of Oemleria cerasiformis have a larger flower display and a longer flowering period than females, and tend to show greater phenological variability. Male inflorescences generally begin to flower sooner than females, but reach their peak and finish flowering later. Their longer blooming period is mainly the result of less synchronous flower opening in males. In both sexes flowering tends to be completed more rapidly in later inflorescences. Fruit set in females is positively correlated with time of flowering (r = 0.313) and inflorescence size (r = 0.421). Hand-pollination of female flowers increased fruit set in most inflorescences, indicating that reproductive success in female O. cerasiformis may be pollen limited.

scholarly journals Accurate position exchange of stamen and stigma by movement in opposite direction resolves the herkogamy dilemma in a protandrous plant, Ajuga decumbens (Labiatae)

AoB Plants ◽  
2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Zhong-Ming Ye ◽  
Xiao-Fang Jin ◽  
Jian Yang ◽  
Qing-Feng Wang ◽  
Chun-Feng Yang
Keyword(s):  
Pollen Viability ◽  
Floral Biology ◽  
Pollen Deposition ◽  
High Viability ◽  
Pollen Removal ◽  
Female Phase ◽  
Male Phase ◽  
Accurate Position ◽  
Sexual Interference ◽  
Position Exchange

Abstract Herkogamy is an effective way to reduce sexual interference. However, the separation of stigma and anther potentially leads to a conflict because the pollen may be placed in a location on the pollinator different from the point of stigma contact, which can reduce pollination accuracy. Floral mechanisms aiming to resolve this conflict have seldom been explored. The floral biology of protandrous Ajuga decumbens was studied to uncover how the herkogamy dilemma can be resolved. Flower anthesis was divided into male, middle, female and wilting phases. The positions of stigma and stamen were dissimilar in different flower development stages. We measured the distance of the stamen and stigma to the lower corolla lip at different floral phases, which was the pollinators’ approaching way. The pollen viability, stigma receptivity, pollen removal and pollen deposition on stigma were investigated at different phases. During the male phase, the dehisced anthers were lower than the stigma, located at the pollinators’ approaching way, and dispersed most pollen with high viability. As the flower developed, the anthers moved upwards, making way for pollen deposition during the female phase. Meanwhile, the stigma becomes receptive by moving into the way and consequently was deposited with sufficient pollen. The position exchange of the stamen and stigma created a dynamic herkogamy at the floral phase with different sexual functions. This floral mechanism effectively avoided sexual interference and maintained pollination accuracy. In Ajuga, the movement herkogamy might be of adaptive significance in response to the changes in the pollination environment.

scholarly journals BIOLOGY OF POLLINATION OF Citrus sinensis VARIETY ‘PERA RIO’

2017 ◽  
Vol 39 (2) ◽  
Author(s):  
GENEROSA SOUSA RIBEIRO ◽  
ELOI MACHADO ALVES ◽  
CARLOS ALFREDO LOPES DE CARVALHO
Keyword(s):  
Citrus Sinensis ◽  
Pollen Viability ◽  
Floral Biology ◽  
High Similarity ◽  
Stigma Receptivity ◽  
Local Agriculture ◽  
Floral Visitor ◽  
Floral Visitors ◽  
Morisita Index ◽  
Number Of Individuals

ABSTRACT Aspects related to the floral biology of Citrus sinensis ‘Pera Rio’ variety were studied in the present work aiming to obtain information about the pollination ecology in the local agriculture. Studies of flowering, anthesis, pollen / ovule ratio, stigmatic receptivity, pollen viability, nectar characterization and floral visitors were carried out. From the data studied, the following information was obtained: C. sinensis variety ‘Pera Rio’ flourishes in two annual periods (dry and rainy), the anthesis occurs from 9:00 AM with duration of 24 hours, during which period stigma receptivity, pollen viability and nectar secretion are highly significant, demonstrating that the species also possesses characteristics of allogenic plants. Apis mellifera was a floral visitor, with a greater number of individuals with a Relative Frequency (RF) of 51.1%. Melipona scutellaris obtained second place in visits with RR = 23.6%; Followed by Trigona spinipes with FR = 17.7%. The two seasons (dry and rainy) presented high similarity (Morisita index = 0.64). C. sinensis has floral biology favorable to cross pollination and bees A. mellifera and M. scutellaris are potential pollinators of this fruit in the conditions in the region of the Recôncavo Baiano. The reproductive system of C. sinensis is mixed, being favorable to entomophilic pollination.

The association between floral longevity and pollen removal, pollen receipt, and fruit production in flame azalea (Rhododendron calendulaceum)

2007 ◽  
Vol 85 (4) ◽  
pp. 414-419 ◽  
Author(s):  
Amy C. Blair ◽  
Lorne M. Wolfe
Keyword(s):  
Life Span ◽  
Fruit Set ◽  
Pollen Dispersal ◽  
Fruit Production ◽  
Solitary Bee ◽  
Female Function ◽  
Floral Longevity ◽  
Pollen Removal ◽  
Selection For ◽  
Pollen Receipt

Floral longevity is an important feature of a plant’s reproductive strategy. The goal of this study was to examine flower life span in the shrub flame azalea ( Rhododendron calendulaceum (Michx.) Torr.) to determine if it is fixed or plastic and to evaluate its association with pollen removal and receipt. Unmanipulated flowers remained open for ~10 days, while hand-pollinated flowers closed earlier (~7 days), indicating that these flowers are subject to pollination-induced senescence. In 2002, pollen removal was rapid (~70% of pollen was removed in the first 2 h of anthesis), while female function was a slower process (pollen accumulated on stigmas for up to 4 days). Fruit set was pollen limited, as 80% of hand-outcrossed flowers set fruit versus 35% of naturally pollinated flowers. This is likely the result of the pollen-collecting behavior of a common solitary bee, which did not contact stigmas. In sharp contrast, 2003 was a cooler and wetter spring, few flower visitors were observed, and virtually no pollen was removed from or deposited on stigmas after 48 h. These results suggest that the flower life span of flame azalea is a result of selection for increasing the probability of pollen receipt rather than pollen dispersal.

scholarly journals The light intensity mediates the pollination efficacy of a Caatinga morning glory Ipomoea bahiensis (Convolvulaceae)

Sociobiology ◽  
2021 ◽  
Vol 68 (4) ◽  
pp. e5906
Author(s):  
Miriam Gimenes ◽  
Laene Silva Araujo ◽  
Anderson Matos Medina
Keyword(s):  
Light Intensity ◽  
Climatic Factors ◽  
Temporal Patterns ◽  
Fruit Production ◽  
Morning Glory ◽  
Flower Opening ◽  
Flower Visitors ◽  
Floral Visitors ◽  
The Times ◽  
Opening And Closing

Pollination is an ecological process that relies on the matching traits of flower visitors and flowers. Morphology, behavior, and temporal patterns play essential roles in mediating the interactions between plants and floral visitors. This study analyzed the temporal aspects of visitors and flowers interaction and the possible adjustment between both organisms.  We used Ipomoea bahiensis and its flower visitors as a model system. We evaluated the visitor frequency on the flowers throughout the day, flower opening and closing times, pollen availability and stigma receptivity. We also evaluated the highest fruit production time during the flower longevity was analyzed, and the time of highest pollinator activity, related to climatic factors. Among the floral visitors, bees, especially Melitoma spp., Apis mellifera, and Pseudaugochlora pandora were the most frequent visitors, presenting regular visits synchronized with the flower opening and closing times, which were also regular. This system was influenced mainly by light intensity. Besides, these bees were very active during the times of the highest fruit production.  These data indicate the presence of temporal patterns for both the bees and the visited plants, and synchronization between them, being the light intensity as a modulator of the rhythms of bees and plant, confirming the importance of the temporal adjustments for pollination efficiency.

Bees are supplementary pollinators of self-compatible chiropterophilous durian

2018 ◽  
Vol 34 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Kanuengnit Wayo ◽  
Chama Phankaew ◽  
Alyssa B. Stewart ◽  
Sara Bumrungsri
Keyword(s):  
Plant Species ◽  
Fruit Set ◽  
Floral Biology ◽  
Apis Dorsata ◽  
Open Pollination ◽  
Insect Pollination ◽  
Insect Pollinator ◽  
Southern Thailand ◽  
Floral Visitors

Abstract:Nocturnally foraging insects may be supplementary pollinators to chiropterophilous plant species when bats are scarce. Given that insects are much smaller than bats, they may be more effective at transferring pollen for plant species with similar stamen and pistil lengths, such as the ‘Monthong’ durian cultivar. The present study clarifies the role of insects in pollinating the ‘Monthong’ cultivar by examining the floral biology, conducting pollination treatments on 19 trees and observing floral visitors in southern Thailand. Stigmas were receptive by 17h00, and over 50% of ‘Monthong’ anthers had dehisced by 17h30. Several bee species began foraging on flowers during the late afternoon, and the giant honey bee (Apis dorsata) continued to visit throughout the night. Our results show that at 4 wk after pollination, the highest fruit set occurred from hand-crossed pollination (13.5%), followed by open pollination (5.5%), insect pollination (3.3%) and automatic autogamy (2.0%), indicating that this cultivar is highly self-incompatible. Moreover, insects appear to be important pollinators of ‘Monthong’ durian in areas where nectar bats visit infrequently. One bee species in particular,Apis dorsata, commonly foraged on flowers at dusk and appears to be the most effective insect pollinator of durian. Our findings highlight that nocturnally foraging bees are capable of securing pollination for night-blooming plant taxa, even those typically considered to be bat-pollinated.

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