The reproductive ecology of island populations of distylous Menyanthes trifoliata (Menyanthaceae)

1998 ◽  
Vol 76 (5) ◽  
pp. 818-828 ◽  
Author(s):  
Faye L Thompson ◽  
Luise A Hermanutz ◽  
David J Innes
Keyword(s):  
Seed Set ◽  
Aquatic Macrophyte ◽  
Pollen Limitation ◽  
Bimodal Distribution ◽  
Stabilizing Selection ◽  
Long Distance ◽  
Anther Length ◽  
Reciprocal Arrangement ◽  
Fruit And Seed Set ◽  
Menyanthes Trifoliata

Menyanthes trifoliata L. is a distylous, clonal aquatic macrophyte found in shallow bogs and river margins throughout the boreal ecosystem, including the island of Newfoundland. A combination of long-distance dispersal and colonization after deglaciation, and pollen limitation resulting from reduced pollinator diversity and abundance documented on islands, predicts the breakdown of heterostyly to favour the establishment of self-compatible homostyles on islands. To test if self-fertilizing homostyles have been selected, variation in floral characters and compatibility relationships were examined in M. trifoliata populations from the Avalon Peninsula of Newfoundland. Morph ratio and its effect on fruit and seed set were examined in nine populations. Of the seven dimorphic populations, morphs occurred in a 1:1 ratio in four populations and deviated significantly from a 1:1 ratio in three populations. The two populations monomorphic for either pin or thrum morphs set few fruits or seeds (<15%). A strictly reciprocal arrangement of stigma height and anther length was not observed between pin and thrum morphs in the majority of populations studied. Stigma-anther separation showed a bimodal distribution with few intermediate "homostylous" flowers, rather than the discreet bimodal distribution typical of distylous species. Fruit and seed set were high (>60%) in equal morph ratio populations and were not significantly correlated to stigma-anther separation, indicating that there was no selective advantage of being homostylous. All three populations tested were highly self-incompatible, confirming that there has not been a breakdown of heterostyly on the island of Newfoundland. A reduced pollinator fauna typical of island environments may have relaxed stabilizing selection for strict herkogamy between floral morphs, resulting in the observed lack of reciprocity.Key words: Menyanthes trifoliata, distyly, homostyle, reciprocal herkogamy, clonal aquatic macrophyte, island of Newfoundland.

The influence of floral morph ratios and low plant density on mating and fertility in a tristylous colonizing species

Botany ◽  
2018 ◽  
Vol 96 (8) ◽  
pp. 533-545 ◽  
Author(s):  
Christopher M. Balogh ◽  
Spencer C.H. Barrett
Keyword(s):  
Field Experiment ◽  
Seed Set ◽  
Plant Density ◽  
Pollen Limitation ◽  
Lythrum Salicaria ◽  
Long Distance ◽  
Experimental Conditions ◽  
Wide Range ◽  
Morph Ratios ◽  
Floral Morph

Sexual reproduction in heterostylous populations may be vulnerable to demographic conditions because of the small number of mating types in populations. Here, we investigate mating and fertility under natural and experimental conditions in tristylous Lythrum salicaria L., an invasive species that exhibits a wide range of floral morph ratios and demographic contexts. We grew 147 open-pollinated seed families from six populations with different morph structures to estimate intermorph mating (d). In a field experiment, we used progeny ratios from 47 spatially isolated individuals to estimate d, and measured the intensity of pollen limitation experienced by the morphs. The M- and S-morphs experienced high rates of d, regardless of population size or morph ratio. Estimates for the L-morph revealed low levels of intramorph mating in three dimorphic and two trimorphic populations, but near complete intramorph mating in a monomorphic population. Despite high levels of intermorph mating in the field experiment, the morphs experienced significant pollen limitation of fruit and seed set, but this did not differ in intensity among the morphs. Our field experiment demonstrates that although plant isolation was associated with pollen limitation of seed set, “long-distance” bee-mediated pollen flow served to maintain intermorph mating. Tristyly in L. salicaria is remarkably robust to the demographic variation associated with colonization.

scholarly journals Pollen limitation and the contribution of autonomous selfing to fruit and seed set in a rewarding orchid

2015 ◽  
Vol 102 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Hans Jacquemyn ◽  
Rein Brys
Keyword(s):  
Seed Set ◽  
Pollen Limitation ◽  
Fruit And Seed Set

Causes of Low Fruit and Seed Set in Bird-Pollinated Anagyris foetida (Leguminosae): Pollen Limitation and Other Extrinsic Factors

2009 ◽  
Vol 45 (1) ◽  
pp. 77-94 ◽  
Author(s):  
Francisco J. Valtueña ◽  
Ana Ortega-Olivencia ◽  
Tomás Rodríguez-Riaño ◽  
Josefa López
Keyword(s):  
Seed Set ◽  
Pollen Limitation ◽  
Extrinsic Factors ◽  
Fruit And Seed Set

Bateman’s principle and plant reproduction: The role of pollen limitation in fruit and seed set

1994 ◽  
Vol 60 (1) ◽  
pp. 83-139 ◽  
Author(s):  
Martin Burd
Keyword(s):  
Seed Set ◽  
Pollen Limitation ◽  
Plant Reproduction ◽  
Fruit And Seed Set

Pollen limitation and reproduction varies with population size in experimental populations of Sabatia angularis (Gentianaceae)

Botany ◽  
2009 ◽  
Vol 87 (3) ◽  
pp. 330-338 ◽  
Author(s):  
Rachel B. Spigler ◽  
Shu-Mei Chang
Keyword(s):  
Reproductive Success ◽  
Population Size ◽  
Intraspecific Competition ◽  
Seed Set ◽  
Pollen Limitation ◽  
Small Populations ◽  
Plant Populations ◽  
Large Populations ◽  
Fruit And Seed Set ◽  
Supplemental Pollination

Individuals in large plant populations are expected to benefit from increased reproductive success relative to those in small populations because of the facilitative effects of large aggregations on pollination. As populations become small, the inability to attract sufficient numbers of pollinators can reduce reproduction via pollen limitation. This study experimentally tested whether such trends occur for the herbaceous biennial Sabatia angularis (L.) Pursh (Gentianaceae). We created artificial populations of varying size consisting of potted S. angularis plants in two field sites to determine whether population size affected mean fruit and seed set. We also examined whether population size affected the degree of pollen limitation using a supplemental pollination design in one of the sites. Our results showed that, on average, seed set was lower in large populations, not small populations, of S. angularis and that this result may be due to increased pollen limitation in large populations. We suggest that in certain contexts, small populations may enjoy reproductive advantages over large populations by escaping intraspecific competition for pollinators.

scholarly journals Influence of environmental factors on the genetic variation of the aquatic macrophyte Ranunculus subrigidus on the Qinghai-Tibetan Plateau

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Zhigang Wu ◽  
Xinwei Xu ◽  
Juan Zhang ◽  
Gerhard Wiegleb ◽  
Hongwei Hou
Keyword(s):  
Genetic Diversity ◽  
Tibetan Plateau ◽  
Environmental Factors ◽  
Local Adaptation ◽  
Aquatic Macrophyte ◽  
Spatial Genetic Structure ◽  
Long Distance ◽  
Elevation Gradients ◽  
Mantel Tests ◽  
Genetic Patterns

Abstract Background Due to the environmental heterogeneity along elevation gradients, alpine ecosystems are ideal study objects for investigating how ecological variables shape the genetic patterns of natural species. The highest region in the world, the Qinghai-Tibetan Plateau, is a hotspot for the studies of evolutionary processes in plants. Many large rivers spring from the plateau, providing abundant habitats for aquatic and amphibious organisms. In the present study, we examined the genetic diversity of 13 Ranunculus subrigidus populations distributed throughout the plateau in order to elucidate the relative contribution of geographic distance and environmental dissimilarity to the spatial genetic pattern. Results A relatively low level of genetic diversity within populations was found. No spatial genetic structure was suggested by the analyses of molecular variance, Bayesian clustering analysis and Mantel tests. Partial Mantel tests and multiple matrix regression analysis showed a significant influence of the environment on the genetic divergence of the species. Both climatic and water quality variables contribute to the habitat heterogeneity of R. subrigidus populations. Conclusions Our results suggest that historical processes involving long-distance dispersal and local adaptation may account for the genetic patterns of R. subrigidus and current environmental factors play an important role in the genetic differentiation and local adaptation of aquatic plants in alpine landscapes.

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.

POLLEN PRODUCTION AND DISSEMINATING PROPERTIES OF TRITICALE RELATIVE TO WHEAT

1972 ◽  
Vol 52 (4) ◽  
pp. 569-574 ◽  
Author(s):  
K. C. YEUNG ◽  
E. N. LARTER
Keyword(s):  
Seed Set ◽  
Marker Gene ◽  
Pollen Grains ◽  
Triticum Aestivum L ◽  
Hybrid Seed Production ◽  
Pollen Production ◽  
Hexaploid Triticale ◽  
Anther Length ◽  
Anther Extrusion ◽  
Wide Range

A study of the pollen production properties of three hexaploid triticale strains (Triticale hexaploide Lart.) showed that their anther length was significantly greater than that of wheat anthers (Triticum aestivum L. em Thell.) and the estimated number of pollen grains per anther ranged from 15,000 to 21,000. In comparison, a total of 8000 grains per anther was estimated for wheat, cult Manitou. Eighty-nine percent anther extrusion occurred in triticale cult Rosner, while Manitou averaged 70% anther extrusion. The period of anthesis of triticale varied according to strain but generally was of longer duration than in Manitou and thereby promoted outcrossing. Using a triticale strain carrying a dominant marker gene, 50% seed-set was obtained at a distance of 12 m leeward of the pollen source; however, a small percentage was still obtained at a distance of 30 m. It would appear from the limited number of triticales used in this study that a wide range of variability exists within this species in its pollen production and disseminating properties. With appropriate selection pressures, strains with an outbreeding habit could be developed for the purpose of hybrid seed production.

Predator Effects on Plant-Pollinator Interactions, Plant Reproduction, Mating Systems, and Evolution

2020 ◽  
Vol 51 (1) ◽  
pp. 319-340
Author(s):  
Amanda D. Benoit ◽  
Susan Kalisz
Keyword(s):  
Mating Systems ◽  
Seed Set ◽  
Pollen Limitation ◽  
Plant Traits ◽  
Plant Reproduction ◽  
Trophic Levels ◽  
Interaction Networks ◽  
Pollinator Abundance ◽  
Plant Pollinator ◽  
Predator Effects

Plants are the foundation of the food web and therefore interact directly and indirectly with myriad organisms at higher trophic levels. They directly provide nourishment to mutualistic and antagonistic primary consumers (e.g., pollinators and herbivores), which in turn are consumed by predators. These interactions produce cascading indirect effects on plants (either trait-mediated or density-mediated). We review how predators affect plant-pollinator interactions and thus how predators indirectly affect plant reproduction, fitness, mating systems, and trait evolution. Predators can influence pollinator abundance and foraging behavior. In many cases, predators cause pollinators to visit plants less frequently and for shorter durations. This decline in visitation can lead to pollen limitation and decreased seed set. However, alternative outcomes can result due to differences in predator, pollinator, and plant functional traits as well as due to altered interaction networks with plant enemies. Furthermore, predators may indirectly affect the evolution of plant traits and mating systems.

Pollen limitation and seed set associated with year-to-year variation in flowering of Gmelina arborea in a natural tropical forest

Grana ◽  
2019 ◽  
Vol 58 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Vinod Prasad Khanduri ◽  
Kewat Sanjay Kumar ◽  
Chandra Mohan Sharma ◽  
Manoj Kumar Riyal ◽  
Kalpataru Kar
Keyword(s):  
Tropical Forest ◽  
Seed Set ◽  
Pollen Limitation ◽  
Gmelina Arborea
Sign in / Sign up

Export Citation Format

Share Document