Enhancing pollen competition by delaying stigma receptivity: Pollen deposition schedules affect siring ability, paternal diversity, and seed production in Collinsia heterophylla (Plantaginaceae)

2011 ◽  
Vol 98 (7) ◽  
pp. 1191-1200 ◽  
Author(s):  
Åsa Lankinen ◽  
Josefin A. Madjidian
Keyword(s):  
Seed Production ◽  
Pollen Competition ◽  
Pollen Deposition ◽  
Stigma Receptivity ◽  
Siring Ability

scholarly journals Autonomous pollination alleviates pollen limitation in the endemic Cienfuegosia yucatanensis Millsp. (Malvaceae)

2020 ◽  
Vol 99 (1) ◽  
pp. 80-91
Author(s):  
Víctor Parra-Tabla ◽  
Conchita Alonso
Keyword(s):  
Seed Production ◽  
Inbreeding Depression ◽  
Seed Weight ◽  
Pollen Limitation ◽  
Pollen Tubes ◽  
Pollen Deposition ◽  
Cross Pollination ◽  
The North ◽  
Hand Pollination ◽  
Self Compatibility

Background: Self-compatibility is common on endemic plant species, but pollen limitation and self-pollination could be risk factors. Study species: The endemic Cienfuegosia yucatanensis (Malvaceae), whose distribution is mainly restricted to the north coast of the peninsula of Yucatán, México. Questions: a) Are flowers of C. yucatanensis autonomous for pollination? b) Are C. yucatanensis fruit or seed-set limited by pollen deposition? and, c) Is there evidence of early inbreeding depression in C. yucatanensis? Study sites and dates: Two sites in the north of the peninsula of Yucatán in a seasonally dry scrubland, in the rainy season of 2013 and 2014. Methods: Number of flowers and fruits were weekly recorded. Flowers were collected to count the number of conspecific pollen load and the number of pollen tubes. Autonomous pollination and pollen limitation were evaluated with a hand-pollination experiment. Inbreeding depression on fruit and seed production, and seed weight was evaluated. Results: Flower and fruit production occur simultaneously and last from August to October. Conspecific pollen deposition on stigmas occurred through the whole flowering season and a maximum of pollen tubes was observed in August. Autonomous pollination treatment lead to similar fruit and seed production than cross-pollination, but open pollination produced significantly more seeds. No significant differences among self- and cross-pollination treatments on fruit and seed production or seed weight, were found.  Conclusions: Our results suggest that self-compatibility combined with a relatively efficient autonomous pollination, are suitable mechanisms for the reproductive assurance in C. yucatanensis, with no apparent effects of early inbreeding depression.

scholarly journals Can Sexual Selection Cause Divergence in Mating System-Related Floral Traits?

2019 ◽  
Author(s):  
Åsa Lankinen ◽  
Maria Strandh
Keyword(s):  
Sexual Selection ◽  
Mating System ◽  
Experimental Evolution ◽  
Seed Set ◽  
Pollen Competition ◽  
Floral Traits ◽  
Mixed Mating ◽  
Stigma Receptivity ◽  
Source Line ◽  
Outcrossing Species

AbstractPremise of the ResearchThe wide diversity of floral traits seen among plants is shaped by neutral and selective evolutionary processes. In outcrossing species, sexual selection from competing pollen donors is expected to be important for shaping mating system-related traits but empirical evidence is scarce. In a previous evaluation of experimental evolution lines crossed with either one or two pollen donors (monogamous, M, or polyandrous, P, lines) at early floral stages in mixed-mating Collinsia heterophylla (Plantaginaceae), P showed enhanced pollen competitive ability and reduced maternal seed set compared to M, in accordance with sexually antagonistic evolution of pollen. Here, we asked whether the presence of sexual selection during pollen competition affect mating system-related floral traits in the same lines.MethodologyWe compared flowering start, timing of anther-stigma contact (as an indication of timing of self-pollination), timing of stigma receptivity and first seed set between M and P, and with a source line, S (starting material). The former three traits are later in outcrossers than in selfers of Collinsia. The latter trait was expected to be earlier in P than in M because of sexual selection for early seed siring of pollen.Pivotal ResultsArtificial polyandry for four generations resulted in later flowering start and later anther-stigma contact in P compared to M, and the latter trait was intermediate in S. Thus, P appeared more ‘outcrossing’ than M. Stigma receptivity did not differ between lines. First seed set was earlier in P than in M, as expected from sexual selection.ConclusionsOur results from C. heterophylla experimental evolution lines suggest that a component of sexual selection during outcross pollination could enhance the patterns of floral divergence commonly found between outcrossers and selfers.

Pollen load, capsule weight, and seed production in three orchid species

1994 ◽  
Vol 72 (2) ◽  
pp. 249-255 ◽  
Author(s):  
H. C. Proctor ◽  
L. D. Harder
Keyword(s):  
Reproductive Success ◽  
Seed Production ◽  
Pollen Deposition ◽  
Pollen Load ◽  
Seed Number ◽  
Orchid Species ◽  
Liquid Suspension ◽  
Ovule Number ◽  
Cypripedium Calceolus ◽  
The Relationship

Relationships between pollen load, seed production, and capsule weight in orchids are important both theoretically and pragmatically. It has been hypothesized that pollen packets (pollinia) evolved in orchids because of selection to produce packages capable of fertilizing all ovules in an ovary; testing this hypothesis requires information about the relationship between pollen load and seed production. As well, because capsules contain thousands to millions of seeds, an easily measured correlate of seed number, such as capsule weight, would be valuable for studies of reproductive success. We hand-pollinated Cypripedium calceolus, Amerorchis rotundifolia, and Calypso bulbosa with different pollen loads, weighed capsules, and estimated seed number by subsampling from liquid suspension. Pollen load affected seed number in Calypso but had no significant effect in Cypripedium or Amerorchis. Capsule weight was positively associated with seed number in all species, but there was considerable variation in R2 across species (from 0.40 to 0.85), indicating that it is unwise to assume that capsule weight is a good measure of relative reproductive success. As well, our data suggest that size of the typical unit of pollen deposition rather than that of the entire pollinarium evolved to match ovule number in orchids. Key words: Orchidaceae, pollen load, capsule weight, seed set.

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 Evaluation of pollinator effectiveness based on pollen deposition and seed production in a gynodieocious alpine plant, Cyananthus delavayi

2017 ◽  
Vol 7 (20) ◽  
pp. 8156-8160 ◽  
Author(s):  
Hao Wang ◽  
Guo-Xing Cao ◽  
Lin-Lin Wang ◽  
Yong-Ping Yang ◽  
Zhi-Qiang Zhang ◽  
...  
Keyword(s):  
Seed Production ◽  
Pollen Deposition ◽  
Alpine Plant ◽  
Pollinator Effectiveness
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