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

2017 ◽  
Vol 65 (2) ◽  
Author(s):  
Luis Diego Rios ◽  
Alfredo Cascante-Marín
Keyword(s):  
Video Recording ◽  
Mountain Forest ◽  
Nectar Production ◽  
Pollinator Visitation ◽  
Southern Mexico ◽  
Tropical Regions ◽  
Self Pollination ◽  
Flowering Season ◽  
Floral Visitor ◽  
Hand Pollination

Pitcairnioideae is the second most diverse subfamily of bromeliads (Bromeliaceae), a group exclusive to tropical regions of the New World. Pitcairnioid bromeliads have floral traits assumed to promote outcrossing through biotic pollination systems; however, the reproductive biology of most of the species of this group has not been documented. Pitcairnia heterophylla is an epiphytic (seldom saxicolous) bromeliad occurring from Southern Mexico, into the Northern Andes. We studied the pollination and breeding system of P. heterophylla in an epiphytic population at a mountain forest in Costa Rica from January to April 2013. We performed hand pollination experiments (agamospermy, autonomous self-pollination, hand self-pollination and hand cross-pollination) on 89 flowers from 23 individuals (3–6 flowers per individual) in 2013 flowering season. Nectar production was measured on 18 unvisited flowers of six individuals with a hand-held refractometer. Simultaneously, floral visitors were recorded on eight individuals with trail cameras for a total of 918 hours (115 ± 52 hours per individual, mean ± SE). Under natural conditions, seed set (540.4 ± 55.2) was similar to manually selfed flowers (516.3 ± 41.5) and autonomously selfed flowers (521.1 ± 29.0), but lower to manually outcrossed flowers (670.2 ± 31.3). The flowers of P. heterophylla are self-compatible, capable of autonomous pollination, and non-agamospermous. Intrafloral self-pollination is facilitated by adichogamy and lack of floral herkogamy. The scentless red flowers of P. heterophylla with tubular corollas and nectar production suggested ornithophilic pollination which was confirmed by video recording of 46 hummingbird visits. The most common floral visitor was the short-billed hummingbird Lampornis calolaemus which accounted for 78 % of the visits. However, the visitation rate during the flowering season was low (0.6 visits per day per plant). Selfing in P. heterophylla might be explained as a mechanism of reproductive assurance and to reduce interspecific pollen flow with taxonomically unrelated plants.

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.

Asymmetrical legitimate pollination in distylous Palicourea demissa (Rubiaceae): the role of nectar production and pollinator visitation

2011 ◽  
Vol 27 (4) ◽  
pp. 393-404 ◽  
Author(s):  
Hamleth Valois-Cuesta ◽  
Pascual J. Soriano ◽  
Juan Francisco Ornelas
Keyword(s):  
Cloud Forest ◽  
Pollen Deposition ◽  
Nectar Production ◽  
Pollinator Visitation ◽  
Visitation Rate ◽  
Floral Visitor ◽  
Floral Visitors ◽  
Floral Visitation ◽  
Nectar Availability

Abstract:We investigated morph differences in attributes that contribute to rewarding floral visitors of the distylous shrub Palicourea demissa at La Mucuy cloud forest in Venezuela. In both morphs, we measured nectar production from flowers subjected to repeated removals at 2-h intervals (10 plants per morph) and flowers that accumulated nectar for 24 h (10 plants per morph). In both cases, floral visitors were excluded. In addition, we quantified nectar availability (30 plants per morph), floral visitation (10–12 plants per morph) and legitimate pollination (30 plants per morph) throughout the day. We explored morph differences in the variables mentioned above using analyses of variance, and the effects of nectar variation on floral visitation and legitimate pollination using regression models. We observed 1205 floral visits, grouped into six hummingbird (94.7%) and three insect species (5.3%), across observations (264 h). Coeligena torquata was the most frequent floral visitor (34%) in both morphs (1.4–1.7 visits per plant h−1). Nectar production and availability, and visitation rate were similar between morphs. Visitation rate and legitimate pollen deposition increased with the nectar production in both morphs, but levels of legitimate pollination were higher on short-styled flowers than long-styled flowers. These results show that short-styled and long-styled flowers reward floral visitors equally, but frequency and foraging behaviour of long-billed pollinators can promote asymmetrical legitimate pollination.

scholarly journals Nectar production and pollination in peach

2000 ◽  
Vol 6 (3) ◽  
Author(s):  
J. Nyéki ◽  
Z. Szabó ◽  
P. Benedek ◽  
L. Szalay
Keyword(s):  
Foraging Behaviour ◽  
Fruit Set ◽  
Open Pollination ◽  
Bee Pollination ◽  
Nectar Production ◽  
Self Pollination ◽  
Hand Pollination ◽  
Artificial Hand

Observations were made at two growing sites, Siófok and Szatymaz, in the years 1998 and 1999, on 16 peach varieties. The production of nectar was measured, the foraging behaviour of bees, fruit set and the effect of exclusion of bee visits for different periods were observed systematically. Production of nectar confirmed earlier data, 9.09 mg per flower in average. There was large variation due to variety and date of observation. Bee visits were relatively abundant. At favourable weather, 1 to 30 visits/flower/day occurred in the average. Artificial hand pollination increased fruit set, substantially. Open pollination yielded superior fruit set than self pollination, without bees. Supplementary bee pollination can be regarded to be beneficial to peach production as well.  

scholarly journals Evidence and Significance of Self-pollination of Avocados in Florida

1994 ◽  
Vol 119 (6) ◽  
pp. 1200-1207 ◽  
Author(s):  
Thomas L. Davenport ◽  
Petra Parnitzki ◽  
Sabine Fricke ◽  
Melanie S. Hughes
Keyword(s):  
Persea Americana ◽  
Stage I ◽  
Stage Ii ◽  
First Year ◽  
Second Stage ◽  
Flying Insects ◽  
Self Pollination ◽  
Flowering Season ◽  
Primary Means ◽  
Second Year

Pollination was investigated in five avocado (Persea americana Mill.) cultivars during two seasons. In the first year, `Simmonds' and `Hardee' branches with inflorescences were covered with cheesecloth bags to prevent pollination by large flying insects during either or both the first (Stage I) and second (Stage II) floral openings. Adjacent, tagged branches were left open as controls. The proportion of pollinated Stage I flowers ranged from <1% in `Simmonds' to 9% in `Hardee.' Pollination rates in Stage II ranged from 15% in `Simmonds' to nearly 69% in `Hardee'. Pollination during Stage II was proportional to the number of white stigmas available during that stage. Stage II pollination rates for bagged flowers and open flowers were similar, even though large flying insects were barred from bagged flowers. In the second year, similar experiments on cultivars Simmonds, Tonnage, Tower 2, and Choquette provided results consistent with those obtained the previous year. Virtually no pollination occurred in bagged Stage I flowers in all cultivars tested, and ≈1% of the open Stage I flowers were pollinated. Pollination of bagged and open Stage II flowers was generally the same within cultivars. The percent pollination of Stage II flowers ranged from a mean of 4.3% to 35%, depending on cultivar. The results show that self-pollination during the Stage II floral opening is the primary means of pollination of commercial cultivars grown in Florida. Moreover, the presence of developing fruits on branches bagged during the flowering season demonstrated that fruit set can occur without pollination by large flying insects.

scholarly journals Intraspecific Seasonal Variation of Flowering Synchronization in a Heterodichogamous Tree

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1509
Author(s):  
Noemi Tel-Zur ◽  
Tamar Keasar
Keyword(s):  
Genetic Diversity ◽  
Seasonal Variation ◽  
Phase Duration ◽  
Male And Female ◽  
Flowering Synchrony ◽  
Flowering Season ◽  
Hand Pollination ◽  
Female Phase ◽  
Male Phase ◽  
Phase Differences

Heterodichogamous reproduction in plants involves two flowering morphs, reciprocal in their timing of male and female sexual functions. The degree of synchrony in floral sex phase, within and between individuals of each morph, determines the flowers’ potential fertilization partners. Complete within-morph synchrony enables across-morph mating alone, whereas unsynchronized floral sex phases may allow fertilization within a plant individual (geitonogamy) or within a morph. We documented the disruption of flowering synchrony in the heterodichogamous Ziziphus spina-christi towards the end of its seven-month flowering season. This desert tree has self-incompatible, protandrous, short-lived (2-day) flowers that open before dawn (‘Early’ morph) or around noon (‘Late’ morph). We counted flowers in the male and female phase on flowering branches that were sampled monthly during the 2016–2018 flowering seasons. In 2018, we also tagged flowers and followed their sex-phase distributions over two days at the start, middle, and end of the season. The switch to the female phase was delayed at the end-season (November-December), and 74% of the flowers did not develop beyond their male phase. Differences in male-phase duration resulted in asynchrony among flowers within each tree and among trees of both flowering morphs. Consequently, fertilization between trees of the same morph becomes potentially possible during the end-season. In controlled hand-pollination assays, some within-morph fertilizations set fruit. The end-season breakdown of synchronous flowering generates variability within morphs and populations. We suggest that this variability may potentially enable new mating combinations in a population and enhance its genetic diversity.

scholarly journals Poor fruit set due to lack of pollinators in Aristolochia manshuriensis (Aristolochiaceae)

2021 ◽  
Vol 154 (1) ◽  
pp. 39-48
Author(s):  
Olga V. Nakonechnaya ◽  
Olga G. Koren ◽  
Vasilii S. Sidorenko ◽  
Sergey A. Shabalin ◽  
Tatyana O. Markova ◽  
...  
Keyword(s):  
Fruit Set ◽  
Pollen Limitation ◽  
Floral Morphology ◽  
Pollen Grains ◽  
Ex Situ ◽  
Colour Pattern ◽  
The Poor ◽  
Self Pollination ◽  
Hand Pollination ◽  
Aristolochia Manshuriensis

Background and aims – Interactions of insects with trap flowers of Aristolochia manshuriensis, a relic woody liana with fragmented natural populations from south-eastern Russia, were studied. Pollination experiments were conducted to identify the causes of the poor fruit set in this plant.Material and methods – The study was carried out at two ex situ sites within the natural range of A. manshuriensis in the suburban zone of the city of Vladivostok (Russia). The floral morphology was examined to verify how it may affect the process of pollination in this species. To test for a probability of self-pollination, randomly selected flowers at the female phase of anthesis (day 1 of limb opening) were hand-pollinated with pollen from the same plant. The daily insect visitation was studied. The pollen limitation coefficient and the number of visitors to the flowers were determined. To identify insects that lay eggs on the flowers, the insects were reared from eggs collected from fallen flowers. Both caught and reared insects were identified.Key results – The floral morphology and the colour pattern of A. manshuriensis are adapted to temporarily trap insects of a certain size. The hand-pollination experiment showed that flowers of this plant are capable of self-pollination by geitonogamy and require a pollinator for successful pollination. The positive value (2.64) for the pollen limitation coefficient indicates a higher fruit set after hand-pollination compared to the control without pollination. The number of visitors to the flowers was low (0.17 visitors per flower per day). Insects from three orders were observed on the flowers: Diptera (up to 90.9%), Coleoptera (8.3%), and Hymenoptera (0.8%). Four species of flies (Scaptomyza pallida, Drosophila transversa (Drosophilidae), Botanophila fugax, and Botanophila sp. 1 (Anthomyiidae)) are capable of transferring up to 2500–4000 pollen grains on their bodies and can be considered as pollinators of A. manshuriensis. Data of the rearing experiment indicate that flies of the families Drosophilidae (S. pallida, D. transversa), Chloropidae (Elachiptera tuberculifera, E. sibirica, and Conioscinella divitis), and Anthomyiidae (B. fugax, B. sp. 1) use A. manshuriensis flowers to lay eggs. Beetles were also collected from the flowers, but they were probably not involved in pollination, because no pollen grains were observed on them during our study.Conclusions – Pollinators of A. manshuriensis include mainly Diptera that lay eggs on the flowers. The poor fruit set (2%) in A. manshuriensis is associated with pollen limitation due to the lack of pollinators, as the number of visitors to flowers was extremely low. This may be due to the fact that the flowers of this species are highly specialized on insects of a certain size for pollination.

scholarly journals Melliferous Potential of Weedy Herbaceous Plants in Crop Fields of Romania from 1949 to 2012

2018 ◽  
Vol 62 (2) ◽  
pp. 149-165 ◽  
Author(s):  
Nicoleta Ion ◽  
Jean-François Odoux ◽  
Bernard E. Vaissière
Keyword(s):  
Plant Species ◽  
Agricultural Practices ◽  
Farming Systems ◽  
Nectar Production ◽  
Crop Fields ◽  
Bee Colony ◽  
Intensive Farming ◽  
Flowering Season ◽  
Companion Plants ◽  
Colony Survival

Abstract Intensive farming systems have led to reduced food availability for honey bees which could be related to their current decline. A global tool is needed in order to assess the melliferous potential of plant species that could be developed as crops or companion plants in such systems. This review is based upon a survey from an extensive dataset collected in Romania over the last sixty years to record the nectar production of 153 weedy species. While there was considerable variation among these plants, we found that the melliferous potential of such large families as the Brassicaceae was low, that of the Apiaceae, Asteraceae and Fabaceae at an intermediate level, and that of the Lamiaceae and Boraginaceae the highest. High nectariferous potential was found to be an important feature of perennial ruderal species. Within the main flowering season, perennials provided much more nectar than annuals. These results could help to develop new agricultural practices more compatible with honey bee colony survival and honey production, as some of these plant species could provide a solution to enable agriculture and beekeeping to coexist in a sustainable way.

Effect of pollen load, self-pollination and plant size on seeds and germination in the endangered pink-lipped spider orchid, Caladenia behrii

2009 ◽  
Vol 57 (4) ◽  
pp. 307 ◽  
Author(s):  
Sophie Petit ◽  
Manfred Jusaitis ◽  
Doug Bickerton
Keyword(s):  
Seed Size ◽  
Plant Size ◽  
Stem Length ◽  
Leaf Width ◽  
Pollen Load ◽  
Seed Number ◽  
Pollinator Effectiveness ◽  
Conservation Programs ◽  
Self Pollination ◽  
Hand Pollination

Caladenia behrii Schltdl. (Orchidaceae) (syn. Arachnorchis behrii) is a sexually deceptive, endangered orchid that produces aggregated pollen as pollinia. It is pollinated by a thynnine wasp, and may also be pollinated incidentally by other insects. Pollinator effectiveness may depend on the number of pollinia that pollinators carry and deposit, and on whether they mediate cross-pollination or self-pollination. To understand the role of pollinators and guide conservation programs, we determined the effect of pollen load (one pollinium v. two pollinia) and self-pollination on seed number, seed (embryo) size and germination at 35 days. We also examined the effect of plant size on seed size and seed number. By using partial correlations with leaf width, seed size, seed number, capsule volume and stem length, we found that leaf width was a good predictor for seed number, and that seed size was not correlated with any of the variables examined. Flowers pollinated with one pollinium and two pollinia did not produce seeds that differed in size or number. Cross-pollinated flowers produced fewer but larger seeds, which germinated faster than did seeds from self-pollinated flowers. We conclude that seed production in the field may be estimated from leaf size, that pollinators carrying one pollinium are as effective as those carrying two pollinia and that selfing affects germination negatively, partly because of the smaller size of selfed seeds. Conservation programs aiming to perform hand-pollination of this species should use crossing with a single pollinium.

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