The Effect of Population Size on Stigma Pollen Load, Fruit Set, and Seed Set in Allium stellatum Ker. (Liliaceae)

1999 ◽  
Vol 160 (4) ◽  
pp. 753-757 ◽  
Author(s):  
Brenda Molano‐Flores ◽  
Stephen D. Hendrix ◽  
Stephen B. Heard
Keyword(s):  
Population Size ◽  
Fruit Set ◽  
Seed Set ◽  
Pollen Load

scholarly journals Phloem-Feeding Herbivores Affect Floral Development and Reproduction in the Etruscan Honeysuckle (Lonicera etrusca Santi)

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 815
Author(s):  
Sandra V. Rojas-Nossa ◽  
José María Sánchez ◽  
Luis Navarro
Keyword(s):  
Fruit Set ◽  
Floral Development ◽  
Seed Set ◽  
Wild Populations ◽  
Ecological Processes ◽  
Trade Offs ◽  
Complex Landscape ◽  
Fruit And Seed Set ◽  
Phloem Feeding ◽  
Growth And Reproduction

Floral development depends on multifactor processes related to genetic, physiological, and ecological pathways. Plants respond to herbivores by activating mechanisms aimed at tolerating, compensating, or avoiding loss of biomass and nutrients, and thereby survive in a complex landscape of interactions. Thus, plants need to overcome trade-offs between development, growth, and reproduction vs. the initiation of anti-herbivore defences. This study aims to assess the frequency of phloem-feeding herbivores in wild populations of the Etruscan honeysuckle (Lonicera etrusca Santi) and study their effects on floral development and reproduction. The incidence of herbivory by the honeysuckle aphid (Hyadaphis passerinii del Guercio) was assessed in three wild populations of the Iberian Peninsula. The effect of herbivory on floral morphology, micromorphology of stigmas and pollen, floral rewards, pollination, and fruit and seed set were studied. The herbivory by aphids reduces the size of flowers and pollen. Additionally, it stops nectar synthesis and causes malformation in pollen and microstructures of stigmas, affecting pollination. As a consequence, fruit set and seed weight are reduced. This work provides evidence of the changes induced by phloem-feeding herbivores in floral development and functioning that affect the ecological processes necessary to maintain the reproductive success of plants.

Pollination ecology of Caryocar brasiliense (Caryocaraceae) in Central Brazil cerrado vegetation

1993 ◽  
Vol 9 (2) ◽  
pp. 199-211 ◽  
Author(s):  
Rogério Gribel ◽  
John D. Hay
Keyword(s):  
Breeding System ◽  
Fruit Set ◽  
Seed Set ◽  
Floral Biology ◽  
Cerrado Vegetation ◽  
Central Brazil ◽  
Glossophaga Soricina ◽  
Caryocar Brasiliense ◽  
Anoura Geoffroyi ◽  
Phyllostomus Discolor

ABSTRACTThe floral biology, breeding system and pollination of Caryocar brasiliense were studied in the cerrado vegetation of Central Brazil. The large, yellowish-cream, brush-like flowers are pollinated mainly by glossophagine bats (Glossophaga soricina and Anoura geoffroyi). Three non-glossophagine bats (Phyllostomus discolor, Vampyrops lineatus and Carollia perspicillata) and two short probosisced hawk moths (Erinyis ello and Pseudosphinx tetrio) may also act as occasional pollinators. Caryocar brasiliense is self-compatible although it sets significantly more fruits when crossed than when selfed. The natural fruit set (fruit/flower ratio) and seed set (seed/ovule ratio) are 3.1% and 1.0% respectively. Most of the fruits and seeds are formed through the action of the flower visitors, despite the fact that about 20% of the non-visited flowers receive self pollen on at least one stigma.

Plant-level fecundity and andromonoecy in three common (Melaleuca styphelioides, M. thymifolia, M. nodosa) and one rare (M. deanei) Melaleuca (Myrtaceae) species of the Sydney region

2014 ◽  
Vol 62 (4) ◽  
pp. 276 ◽  
Author(s):  
Alison Hewitt ◽  
Paul Holford ◽  
Adrian Renshaw ◽  
Anthony Haigh ◽  
E. Charles Morris
Keyword(s):  
Reproductive Performance ◽  
Fruit Set ◽  
Seed Set ◽  
Low Frequency ◽  
Common Species ◽  
Flowering Plants ◽  
Breeding Systems ◽  
Small Populations ◽  
Small Field ◽  
Plant Level

This paper reports plant-level measures of reproductive performance from large and small field populations of the vulnerable species Melaleuca deanei F.Meull. compared with three common species within the genus: Melaleuca nodosa (Sol. ex Gaertn.) Sm., Melaleuca thymifolia Sm. and Melaleuca styphelioides Sm. Measures reported include average seed numbers per capsule and per plant; average fruit loads per plant; the proportion of buds that become flowers and thence fruits (fruit set); the number of ovules per flower and seed : ovule ratios (seed set); and floral morphologies. Results indicate that when M. deanei flowers, bud to flower ratios and flower to fruit ratios are not reduced compared with the congeners or between large and small populations. Seed loads per plant held by fruiting plants were comparable between the species and between large and small populations of M. deanei. Seed to ovule ratios were in the order of 5–9% in M. nodosa; 5–7% in M. styphelioides; 7–10% in M. deanei; and 12–15% in M. thymifolia. Larval herbivory of ovules was recorded in M. nodosa and pre-dispersal seed predation noted in M. thymifolia. Andromonoecy was recorded in two of the species at rates of 0.9–3.1% (M. deanei) and 2.9–7% (M. thymifolia). Results suggest that seed production within smaller populations of M. deanei is poor because of a low frequency of flowering and a low proportion of flowering plants per population, rather than plant-level pollination, fruit- or seed-set barriers. Further study is needed to determine the triggers to flowering, the breeding systems, the extent of clonality and the germination and establishment requirements in these species.

scholarly journals Pollen adaptation to ant pollination: a case study from the Proteaceae

2020 ◽  
Vol 126 (3) ◽  
pp. 377-386 ◽  
Author(s):  
Nicola Delnevo ◽  
Eddie J van Etten ◽  
Nicola Clemente ◽  
Luna Fogu ◽  
Evelina Pavarani ◽  
...  
Keyword(s):  
Seed Set ◽  
Germination Rate ◽  
Pollen Grains ◽  
Relative Effect ◽  
The Other ◽  
Pollen Load ◽  
Pollination Services ◽  
Ant Pollination ◽  
Negative Effect ◽  
Floral Visitors

Abstract Background and Aims Ant–plant associations are widely diverse and distributed throughout the world, leading to antagonistic and/or mutualistic interactions. Ant pollination is a rare mutualistic association and reports of ants as effective pollinators are limited to a few studies. Conospermum (Proteaceae) is an insect-pollinated genus well represented in the south-western Australia biodiversity hotspot, and here we aimed to evaluate the role of ants as pollinators of C. undulatum. Methods Pollen germination after contact with several species of ants and bees was tested for C. undulatum and five co-flowering species for comparison. We then sampled the pollen load of floral visitors of C. undulatum to assess whether ants carried a pollen load sufficient to enable pollination. Lastly, we performed exclusion treatments to assess the relative effect of flying- and non-flying-invertebrate floral visitors on the reproduction of C. undulatum. For this, we measured the seed set under different conditions: ants exclusion, flying-insects exclusion and control. Key Results Pollen of C. undulatum, along with the other Conospermum species, had a germination rate after contact with ants of ~80 % which did not differ from the effect of bees; in contrast, the other plant species tested showed a drop in the germination rate to ~10 % following ant treatments. Although ants were generalist visitors, they carried a pollen load with 68–86 % of suitable grains. Moreover, ants significantly contributed to the seed set of C. undulatum. Conclusions Our study highlights the complexity of ant–flower interactions and suggests that generalizations neglecting the importance of ants as pollinators cannot be made. Conospermum undulatum has evolved pollen with resistance to the negative effect of ant secretions on pollen grains, with ants providing effective pollination services to this threatened species.

Degree of fragmentation and population size do not adversely affect reproductive success of a rare shrub species, Banksia nivea (Proteaceae), in a naturally fragmented community

2019 ◽  
Vol 191 (2) ◽  
pp. 261-273 ◽  
Author(s):  
Rujiporn Thavornkanlapachai ◽  
Margaret Byrne ◽  
Colin J Yates ◽  
Philip G Ladd
Keyword(s):  
Population Size ◽  
Fruit Set ◽  
Medium Size ◽  
Fragmented Landscape ◽  
Pollinator Visitation ◽  
High Germination ◽  
Germination Success ◽  
Landscape System ◽  
Density Population ◽  
Degree Of Fragmentation

Abstract Fragmentation of plant communities is generally considered to be detrimental to the survival of the constituent species, especially those that are rare. We investigated the effects of fragmentation on reproductive biology in nine populations of the rare taxon Banksia nivea subsp. uliginosa, differing in size and habitat context. Small mammals were the main pollinator, with lower contributions from honeybees and birds (honeyeaters). There was no significant relationship between population size, fruit set and seed germinability. Fruit set was marginally highest (25.5 ± 3.4) in medium size populations and was variable over years. Lower fruit set (1.0 ± 0.6) in the smallest population may be due to inbreeding depression or lack of pollinators in a degraded habitat, but low fruit set was also observed in the largest population despite high levels of gene flow, possibly due to low pollinator visitation rate in a low-density population. Seeds from all populations had high germination success (>93.4%). Predation occurred in up to 56% of fruit and increased with increasing population size, but was not significantly different between populations of different size. Our study provided evidence that the reproductive output in species in a naturally fragmented landscape system may be resilient to reduced population size and other influences of anthropogenic fragmentation.

Pollination and Seed Set of Banksia spinulosa: Evidence for Autogamy

1988 ◽  
Vol 36 (6) ◽  
pp. 633 ◽  
Author(s):  
G Vaughton
Keyword(s):  
New England ◽  
Breeding System ◽  
Seed Weight ◽  
National Park ◽  
Fruit Set ◽  
Seed Set ◽  
Pollen Vectors ◽  
Specific Variation ◽  
Number Of Seeds

The breeding system of Banksia spinulosa var. neoanglica in the New England National Park was examined by excluding pollen vectors and hand pollinating inflorescences. Fruit set of xenogamous and open inflorescences was greater than geitonogamous and autogamous treatments, although not all differences were significant. No differences were found in the number of seeds per follicle or seed weight between treatments. A reduced number of follicles and smaller seeds occurred in the apical third of inflorescences in all treatments. This report of autogamous seed set contrasts with previous findings for this species and indicates intra-specific variation in the breeding system.

The pollination ecology of the late-successional tree, Oroxylum indicum (Bignoniaceae) in Thailand

2008 ◽  
Vol 24 (05) ◽  
pp. 477-484 ◽  
Author(s):  
Tuanjit Srithongchuay ◽  
Sara Bumrungsri ◽  
Ekapong Sripao-raya
Keyword(s):  
Plant Species ◽  
Fruit Set ◽  
Pollen Grains ◽  
Pollen Load ◽  
Pollination Success ◽  
Oroxylum Indicum ◽  
Tropical Plant ◽  
Fruit Bat ◽  
Highly Sensitive ◽  
Multiple Species

Abstract:Although plant species that attract multiple species of pollinators predominate in tropical plant communities, pollination specialists appear to be at a greater advantage in tropical ecosystems in which pollinators are numerous and many plants flower synchronously. The present study determined the breeding system and legitimate pollinators ofOroxylum indicumVent. in Songkhla and Patthalung Provinces, Thailand.Oroxylum indicumexhibits steady-state flowering, with one or two flowers per inflorescence opening each night. Flowers open in the evening and drop off shortly after midnight, while its bilabiate stigma is highly sensitive, and quickly close upon being touched.Oroxylum indicumis self-incompatible. Hand-cross pollination and open pollination yielded the highest pollination success (47.7% and 31.2% respectively, n = 7 trees). About 900 pollen grains are needed for initiating fruit set. It is confirmed that a fruit bat,Eonycteris spelaea, is the legitimate pollinator. Bats are responsible for all pollen load and the pollen load from only one visit is generally sufficient to initiate fruit set. AlthoughEonycteris spelaeais effective, it is an inefficient pollinator. Compared with plant species pollinated by multiple animal species, the likelihood of pollination failure resulting from the decline in populations ofEonycteris spelaeawill be much more intense inOroxylum indicum.

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