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.

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.

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 Use of a Managed Solitary Bee to Pollinate Almonds: Population Sustainability and Increased Fruit Set

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 56
Author(s):  
Jordi Bosch ◽  
Sergio Osorio-Canadas ◽  
Fabio Sgolastra ◽  
Narcís Vicens
Keyword(s):  
Fruit Set ◽  
Fruit Production ◽  
Small Population ◽  
Solitary Bee ◽  
Female Population ◽  
Visitation Rates ◽  
Population Sustainability ◽  
Effective Pollinator ◽  
Set Distance ◽  
Almond Orchard

Osmia spp. are excellent orchard pollinators but evidence that their populations can be sustained in orchard environments and their use results in increased fruit production is scarce. We released an Osmia cornuta population in an almond orchard and measured its population dynamics, as well as visitation rates and fruit set at increasing distances from the nesting stations. Honeybees were 10 times more abundant than O. cornuta. However, the best models relating fruit set and bee visitation included only O. cornuta visitation, which explained 41% and 40% of the initial and final fruit set. Distance from the nesting stations explained 27.7% and 22.1% of the variability in initial and final fruit set. Of the 198 females released, 99 (54.4%) established and produced an average of 9.15 cells. Female population growth was 1.28. By comparing our results with those of previous O. cornuta studies we identify two important populational bottlenecks (female establishment and male-biased progeny sex ratios). Our study demonstrates that even a small population of a highly effective pollinator may have a significant impact on fruit set. Our results are encouraging for the use of Osmia managed populations and for the implementation of measures to promote wild pollinators in agricultural environments.

scholarly journals Blueberry Floral Attributes and Their Effect on the Pollination Efficiency of an Oligolectic Bee, Osmia ribifloris Cockerell (Megachilidae: Apoidea)

HortScience ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Blair J. Sampson ◽  
Stephen J. Stringer ◽  
Donna A. Marshall
Keyword(s):  
Fruit Set ◽  
Fruit Production ◽  
Flower Size ◽  
Floral Traits ◽  
Solitary Bee ◽  
Pollination Efficiency ◽  
Seed Number ◽  
Cross Pollination ◽  
Berry Size ◽  
Fruit Abortion

We evaluated relationships between floral traits of 23 genotypes of southern blueberries and indices of pollination efficiency (fruit set, fruit abortion, seed number, and berry size) for Osmia ribifloris Cockerell, a manageable solitary bee. Flower size in Vaccinium and presumably ovary size were proportional to berry size, except for the tiny blooms of one V. tenellum clone (NC7808), which produce large commercial-sized berries of ≈2 g. Longer-styled blueberry flowers visited by O. ribifloris produced the heaviest berries with the most seeds. Osmia ribifloris reliably pollinated ‘Climax’ and ‘Tifblue’ rabbiteye blueberries. However, the peculiarly misshapen blooms of ‘Premier’ rabbiteye blueberry receive less pollination from O. ribifloris and yield berries containing 25% fewer seeds. Fruit set for these misshapen ‘Premier’ flowers was equivalent to that of intact flowers indicating that this floral polymorphism would not greatly alter cultivar performance. For seven Vaccinium species, wild and cultivated alike, 80% to 100% of a plant’s fruit production depends on efficient cross-pollination by bees such as O. ribifloris.

scholarly journals 236 Breeding and Selection for Low-bearing Papaya in the Virgin Islands

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 482F-483
Author(s):  
T.W. Zimmerman ◽  
J.A. Kowalski
Keyword(s):  
Carica Papaya ◽  
Fruit Set ◽  
Virgin Islands ◽  
Fruit Production ◽  
Papaya Ringspot Virus ◽  
Annual Crop ◽  
High Incidence ◽  
Early Production ◽  
Selection For ◽  
The U.S

Demand for locally produced papaya fruit (Carica papaya) far outweighs the supply in the U.S. Virgin Islands. Due to the high incidence of papaya ringspot virus (PRSV), papayas are grown as an annual crop. The need exists in the Virgin Islands for papayas with early production to ensure a marketable crop before being devastated by PRSV. Breeding and selection has been ongoing for 5 years to develop papayas with tolerance to PRSV and fruit production starting at or less than 60 cm from the ground. The height at first fruit set, of 15 papaya cultivars recommended for the Virgin Islands, ranges from 58 cm to 253 cm. Generally, female plants started setting fruit lower on the stem than hermaphroditic plants. Through breeding and selection, three papaya lines have been developed that set the first fruit between 40 and 60 cm from the ground and exhibit tolerance to PRSV. These low-bearing papaya lines produce fruit that are marketable 1 month earlier than other cultivars.

Reproductive Responses of Capsicum annuum to High Temperatures

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 543c-543
Author(s):  
Ami N. Erickson ◽  
Albert H. Markhart
Keyword(s):  
Capsicum Annuum ◽  
High Temperatures ◽  
Fruit Development ◽  
Flower Development ◽  
Fruit Set ◽  
Fruit Production ◽  
Yield Reduction ◽  
Bud Size ◽  
Growth Chambers ◽  
Constant Growth

Fruit yield reduction due to high temperatures has been widely observed in Solanaceous crops. Our past experiments have demonstrated that Capsicum annuum cultivars Ace and Bell Boy completely fail to produce fruit when grown at constant 33 °C. However, flowers are produced, continually. To determine which stages of flower development are sensitive to high temperatures, pepper buds, ranging in size from 1 mm to anthesis, were exposed to high temperatures for 6 hr, 48 hr, 5 days, or for the duration of the experiment. Fruit set for each bud size was determined. Exposure to high temperatures at anthesis and at the 2-mm size stage for 2 or more days significantly reduced fruit production. To determine whether inhibition of pollination, inhibition of fertilization, and/or injury to the female or male structures prevents fruit production at high temperatures, flowers from pepper cultivars Ace and Bell Boy were grown until flowers on the 8th or 9th node were 11 mm in length. Plants were divided between 25 °C and 33 °C constant growth chambers for 2 to 4 days until anthesis. At anthesis, flowers from both treatments were cross-pollinated in all combination, and crosses were equally divided between 33 or 25 °C growth chambers until fruit set or flowers abscised. All flower crosses resulted in 80% to 100% fruit set when post-pollination temperatures were 25 °C. However, post-pollination temperatures of 33 °C significantly reduced fruit production. Reduced fruit set by flowers exposed to high temperatures during anthesis and pollination is not a result of inviable pollen or ovule, but an inhibition of fertilization or initial fruit development.

scholarly journals Carbohidratos y Floración en Hesperaloë funifera (Koch) Trel. (Samandoque)

2017 ◽  
pp. 67
Author(s):  
Steven P. Mclaughlin ◽  
Ryan R. Williams
Keyword(s):  
Fruit Set ◽  
Fruit Production ◽  
Hesperaloe Funifera

Several researchers have noted that flowering in Agavaceae requires substantial resources, but few studies have attempted to directly measure such resources. T his study addresses the hypothesis that fruit set in Hesperaloë funifera is limited by available carbohydrates. The accumulation of total non-structural carbohydrates (TNC) prior to flowering was measured, and total requirements for carbohydrate were estimated. Hesperaloë funifera was found to accumulate fructans, and roots were an important organ for storage of accumulated carbohydrates. Carbohydrates stored in the plant prior to flowering are sufficient to meet only about onethird of the carbohydrate needed to produce an average inflorescence with 1 % to 2% fruit set. All of the carbohydrate produced by photosynthesis from May through August is needed to support flowering and fruit production. Low percentage fruit set in Hesperaloë funifera is probably due to a deficiency of carbohydrate resources.

scholarly journals Bee-Mediated Selection Favors Floral Sex Specialization in a Heterantherous Species: Strategies to Solve the Pollen Dilemma

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1685
Author(s):  
Larissa C. Oliveira ◽  
Alberto L. Teixido ◽  
Renata Trevizan ◽  
Vinícius L. G. Brito
Keyword(s):  
Floral Morphology ◽  
Pollen Dispersal ◽  
Fitness Components ◽  
Selection Gradients ◽  
Selective Pressures ◽  
Pollen Removal ◽  
Broad Variation ◽  
Phenotypic Gender ◽  
Pollen Flowers ◽  
Two Populations

Animal-pollinated plants show a broad variation in floral morphology traits and gametophyte production within populations. Thus, floral traits related to plant reproduction and sexuality are usually exposed to pollinator-mediated selection. Such selective pressures may be even stronger in heterantherous and pollen flowers, in which pollen contributes to both bee feeding and pollination, overcoming the “pollen dilemma” or the inability to perform both functions simultaneously. We describe the phenotypic gender and sexual organ morphology of flowers in two populations of Macairea radula (Melastomataceae), a heterantherous and buzz-pollinated species with pollen flowers. We estimated selection gradients on these traits through female and male fitness components. Both populations showed sizeable phenotypic gender variation, from strict hermaphrodites to increased femaleness or maleness. We found a continuous variation in style and stamen size, and this variation was correlated with corresponding shape values of both sexual organs. We detected bee-mediated selection towards short and long styles through seed number and towards intermediate degrees of heteranthery through pollen removal in one population, and selection towards increased maleness through pollen dispersal in both populations. Our results suggest that bee-mediated selection favors floral sex specialization and stylar dimorphism in M. radula, optimizing reproductive success and solving the pollen dilemma.

scholarly journals A Sexually Dimorphic Corolla Appendage Affects Pollen Removal and Floral Longevity in Gynodioecious Cyananthus delavayi (Campanulaceae)

PLoS ONE ◽  
2015 ◽  
Vol 10 (1) ◽  
pp. e0117149 ◽  
Author(s):  
Yang Niu ◽  
Zhi-Qiang Zhang ◽  
Chang-Qiu Liu ◽  
Zhi-Min Li ◽  
Hang Sun
Keyword(s):  
Sexually Dimorphic ◽  
Floral Longevity ◽  
Pollen Removal

scholarly journals Pollen dispersal and fruit production inVaccinium oxycoccosand comparison with its sympatric congenerV. uliginosum

Plant Biology ◽  
2012 ◽  
Vol 15 (2) ◽  
pp. 344-352 ◽  
Author(s):  
F. Van Rossum ◽  
N. J. Vereecken ◽  
E. Brédat ◽  
D. Michez
Keyword(s):  
Pollen Dispersal ◽  
Fruit Production
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