scholarly journals Quantitative importance of staminodes for female reproductive success in Parnassia palustris under contrasting environmental conditions

2003 ◽  
Vol 81 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Sylvi M Sandvik ◽  
Ørjan Totland
Keyword(s):  
Reproductive Success ◽  
Seed Set ◽  
Plant Traits ◽  
Female Reproduction ◽  
Female Reproductive Success ◽  
Pollinator Visitation ◽  
Visitation Rate ◽  
Pollinator Visitation Rate ◽  
Insect Activity ◽  
Pollination Strategy

The five sterile stamens, or staminodes, in Parnassia palustris act both as false and as true nectaries. They attract pollinators with their conspicuous, but non-rewarding tips, and also produce nectar at the base. We removed staminodes experimentally and compared pollinator visitation rate and duration and seed set in flowers with and without staminodes in two different populations. We also examined the relative importance of the staminode size to other plant traits. Finally, we bagged, emasculated, and supplementary cross-pollinated flowers to determine the pollination strategy and whether reproduction was limited by pollen availability. Flowers in both populations were highly dependent on pollinator visitation for maximum seed set. In one population pollinators primarily cross-pollinated flowers, whereas in the other the pollinators facilitated self-pollination. The staminodes caused increased pollinator visitation rate and duration to flowers in both populations. The staminodes increased female reproductive success, but only when pollen availability constrained female reproduction. Simple linear regression indicated a strong selection on staminode size, multiple regression suggested that selection on staminode size was mainly caused by correlation with other traits that affected female fitness.Key words: staminodes, insect activity, seed set, spatial variation, Parnassia palustris.

A comparison of flower-visiting insects to rare Symphyotrichum sericeum and common Solidago nemoralis (Asteraceae)

Botany ◽  
2010 ◽  
Vol 88 (3) ◽  
pp. 241-249 ◽  
Author(s):  
Diana Bizecki Robson
Keyword(s):  
Seed Set ◽  
Visitation Rate ◽  
Hand Pollination ◽  
Insect Visitation ◽  
The Common ◽  
Insect Activity ◽  
Flower Visiting ◽  
Common Plant ◽  
Insect Visitors ◽  
Over Time

Flower-visiting insect activity to the rare Symphyotrichum sericeum (Vent.) G.L. Nesom and the common Solidago nemoralis Ait. var. longipetiolata (Mack. & Bush) Pal. & Steyerm. was examined to detect compositional and temporal similarities. A hand pollination experiment was conducted to determine whether pollen was limiting seed set. Of the 31 insect taxa that visited these plants, Bombus bifarius Cresson was the most common visitor to both species. More insect visitors of the Halictidae and Bombyliidae were received by S. sericeum than S. nemoralis, which received more visitors of the Syrphidae and Tachinidae. The insect visitation rate was not significantly different between the two plant species. Solidago nemoralis was visited by fewer insect taxa per day than S. sericeum, but the constancy of its visitors was higher. The insect visitor composition changed over time, with B. bifarius ignoring S. sericeum plants initially, then visiting them more frequently as the number of receptive S. nemoralis capitula declined. Hand pollination increased seed set in the earliest flowering capitula of S. sericeum, but not for those flowering during the peak. This research shows that the quantity of insect visits to the rare plant is comparable with that of the common plant but that pollination quality may be lower, particularly for early blooming capitula.

scholarly journals High selfing capability and low pollinator visitation in the epiphyte Pitcairnia heterophylla (Bromeliaceae) at a Costa Rican cloud forest

2016 ◽  
Author(s):  
Luis D. Ríos ◽  
Alfredo Cascante-Marín
Keyword(s):  
Cloud Forest ◽  
Video Recording ◽  
Floral Traits ◽  
Nectar Production ◽  
Pollinator Visitation ◽  
Visitation Rate ◽  
Pollinator Visitation Rate ◽  
Hand Pollination ◽  
Pollination Systems ◽  
Epiphytic Bromeliads

AbstractMost epiphytic bromeliads exhibit specialized pollination systems likely to promote out-crossing but, at the same time, possess floral traits that promote autonomous selfing. Adaptations that promote selfing in flowering plants with specialized pollination systems have been considered as a mechanism for reproductive assurance. In this paper, we analyzed the breeding system and pollinator visitation rate of the hummingbird-pollinated bromeliad Pitcairnia heterophylla in order to see if they fit such trend. We performed hand pollination experiments, video recording of floral visitors, and recorded floral traits in order to describe the reproductive and pollination system of the studied species in a cloud forest in Costa Rica. Results from the pollination treatments indicated that P. heterophylla is self-compatible (SCIf = 0.77), capable of autonomous pollination (AFIf = 0.78), and non-agamospermous (AGf = 0.01). Floral traits, such as scentless red flowers, with tubular corolla and nectar production, suggested ornithophily which was confirmed by the video recording of Lampornis calolaemus (Trochilidae) visiting flowers. However, the visitation rate was low (0.6 visits day-1 per plant) based on 918 hours of video recording using trail cameras. We suggest that the high selfing capability of the studied population of P. heterophylla might be related to the low pollinator visitation rate. If low pollinator visitation is common among hummingbird-pollinated and epiphytic bromeliads, then selfing could be a widespread mechanism to enhance their reproductive success.

Floral Herbivory Affects Female Reproductive Success and Pollinator Visitation in the Perennial Herb Alstroemeria ligtu (Alstroemeriaceae)

2011 ◽  
Vol 172 (9) ◽  
pp. 1130-1136 ◽  
Author(s):  
Carezza Botto-Mahan ◽  
Patricia A. Ramírez ◽  
Carmen Gloria Ossa ◽  
Rodrigo Medel ◽  
Manuel Ojeda-Camacho ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Perennial Herb ◽  
Female Reproductive Success ◽  
Pollinator Visitation ◽  
Floral Herbivory

Pollination and reproductive success in the gynodioecious endemic Thymus loscosii (Lamiaceae)

2005 ◽  
Vol 83 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Maria Renée Orellana ◽  
Anna Maria Rovira ◽  
Cèsar Blanché ◽  
Maria Bosch
Keyword(s):  
Reproductive Success ◽  
Seed Quality ◽  
Seed Set ◽  
Pollen Deposition ◽  
Pollinator Visitation ◽  
Heterospecific Pollen ◽  
Pollen Loads ◽  
Visual Attraction ◽  
Insect Exclusion ◽  
Two Populations

Sexual dimorphism can have implications in the reproductive biology of gynodioecious species, affecting sex fitness. We explored the effects of flower sex on pollination visitation rates and pollinator efficiency in terms of stigmatic pollen loads, as well as on quantitative and qualitative aspects of reproductive success in two populations of Thymus loscosii Willk. (Lamiaceae) endemic to the northeastern Iberian Peninsula. We also assessed the dependence of T. loscosii on insect pollination in both hermaphrodite and female plants by performing an insect exclusion test. Apis mellifera and different species of Bombylidae were the most frequent pollinators (68% of approaches to studied plots and 93% of total visited flowers). Hermaphrodite plants received more visits than female ones, possibly as a response to visual attraction, since flowers of the former are larger. Conspecific pollen deposition was higher on stigmas of hermaphrodite flowers than on those of females; in contrast, female stigmas received more heterospecific pollen loads, notably higher in one population. Despite these differences, seed set from open-pollinated flowers was similar in both sexes and in both populations, and relatively low (around 0.5–1 nutlet per fruiting calyx, on average). Thymus loscosii is self-compatible as it was able to produce seeds by spontaneous selfing, but at very low rates, indicating that it is insect-dependent for pollination. In addition, bagged female flowers also set seeds formed by apomitic mechanisms. In general, seeds from females were slightly heavier and began to germinate earlier and at higher rates than those from hermaphrodites, even those formed by apomixis. These results suggest that female plants enjoy a resource allocation advantage that allows increased seed quality and contributes to the maintenance of gynodioecy.Key words: gynodioecy, pollinator visitation, pollen loads, seed set, sex fitness, Thymus loscosii.

Pollen limitation in an experimental population of the wild radish Raphanus raphanistrum

1997 ◽  
Vol 75 (1) ◽  
pp. 72-73
Author(s):  
Karin S. Pfennig ◽  
Jeffrey K. Conner
Keyword(s):  
Reproductive Success ◽  
Key Words ◽  
Fruit Set ◽  
Seed Set ◽  
Pollen Limitation ◽  
Experimental Population ◽  
Wild Radish ◽  
Raphanus Raphanistrum ◽  
Female Fitness ◽  
Female Reproductive Success

Experimental hand-pollinations were performed on a sample of wild radish, Raphanus raphanistrum, to determine whether female reproductive success was pollen limited. Fruit set was found to increase with receipt of supplemental pollen, but seed set did not. These results contradict findings in another Raphanus species but are expected if seeds are aborted or matured in packages. Key words: pollen limitation, Raphanus raphanistrum, female fitness.

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