Heterostyly in a tropical weed: the reproductive biology of the Turnera ulmifolia complex (Turneraceae)

1978 ◽  
Vol 56 (15) ◽  
pp. 1713-1725 ◽  
Author(s):  
S. C. H. Barrett
Keyword(s):  
Seed Dispersal ◽  
New World ◽  
Clonal Propagation ◽  
Seed Set ◽  
Reproductive Capacity ◽  
Weed Species ◽  
Long Distance ◽  
Floral Dimorphism ◽  
Self Compatibility ◽  
Turnera Ulmifolia

Turnera ulmifolia (Turneraceae) is a polymorphic complex native to the New World tropics which is composed of heterostylous and homostylous forms. The distylous varieties elegans, intermedia, and surinamensis exhibit the typical expression of heterostyly. Floral dimorphism is associated with a strong self-incompatibility system and size dimorphism of pollen. Approximately equal representation of floral morphs occurred in 24 out of 28 New World populations surveyed. In 9 out of 10 populations studied, there were no significant differences between the seed fecundity of floral forms. Populations of the homostylous variety angustifolia are self-compatible and produce monomorphic pollen.In contrast to the majority of heterostylous species, some varieties of T. ulmifolia are ruderal weeds. Varieties angustifolia, elegans, and intermedia are also used as garden ornamentals, and man has played a major role in the expansion of their ranges. Weediness in T. ulmifolia is not associated with features commonly found in other weed species, such as self-compatibility, vigorous clonal propagation, and long-distance seed dispersal. However, the continuous year-round flowering of T. ulmifolia plants gives populations a high reproductive capacity. Seed dispersal is by ants which transport seeds relatively short distances. Local seed dispersal favors the establishment of dense populations and increases the likelihood of seed set. Hence the dispersal system of T. ulmifolia appears to be coadapted with the population requirements of the breeding system.

Assessing the effect of inbreeding and long-distance gene flow on the invasive potential of Senecio pterophorus (Asteraceae)

2008 ◽  
Vol 56 (6) ◽  
pp. 539 ◽  
Author(s):  
Lidia Caño ◽  
Josep Escarré ◽  
José M. Blanco-Moreno ◽  
F. Xavier Sans
Keyword(s):  
Gene Flow ◽  
Inbreeding Depression ◽  
Seed Set ◽  
Spanish Population ◽  
Alien Invasive Species ◽  
Invasive Potential ◽  
Long Distance ◽  
Introduced Range ◽  
Self Compatibility ◽  
Introduced Population

Alien invasive species undergo genetic bottlenecks during the colonisation of new areas that can lead to a loss of genetic variation within populations and to subsequent reproductive constraints. We analysed the self-compatibility and the effects of inbreeding and inter-population gene flow in the fitness of one native and one introduced population of the invasive Senecio pterophorus D.C. Plants were self-pollinated and outcrossed within families, within populations, between local populations and between populations located in the native and introduced range. Self-pollinated individuals from both populations produced almost no seeds, thus revealing self-incompatibility. High family-level variation was observed in the effect of pollination treatment on seed set and total fitness. Overall, in the Spanish population, related crosses produced fewer seeds and lower germination rates than unrelated crosses. In the South African population, inbreeding depression affected the probability of flowering. Heterosis was found to affect seed set in both populations and growth and mean pre-reproductive time in the Spanish population. We discuss the effects of the incompatibility system, inbreeding depression and long-distance gene flow within the introduced population with respect to the invasive potential of S. pterophorus in north-eastern Spain.

Mechanistic Analytical Models for Long-Distance Seed Dispersal by Wind

2005 ◽  
Vol 166 (3) ◽  
pp. 368 ◽  
Author(s):  
Katul ◽  
Porporato ◽  
Nathan ◽  
Siqueira ◽  
Soons ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Analytical Models ◽  
Long Distance

CORRELATED RESPONSE IN BROWN SARSON

1970 ◽  
Vol 12 (4) ◽  
pp. 905-913 ◽  
Author(s):  
T. Swamy Rao
Keyword(s):  
Gamma Irradiation ◽  
Seed Set ◽  
Previous History ◽  
The Self ◽  
Correlated Response ◽  
History Of ◽  
Self Compatibility ◽  
Selection For ◽  
Direction Opposite ◽  
Brown Sarson

The correlated response with changes in self-compatibility in three varieties of brown sarson subjected to gamma irradiation was examined. Selection for improved seed set in the irradiated populations showed that substantial correlated response can result for a constellation of other characters in which the self-compatible and self-incompatible forms differ. The correlated response was in a direction opposite to that of the previous history of selection.

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 Historical Biogeography of the New World Solitaires (Myadestes SPP)

The Auk ◽  
2007 ◽  
Vol 124 (3) ◽  
pp. 868-885 ◽  
Author(s):  
Matthew J. Miller ◽  
Eldredge Bermingham ◽  
Robert E. Ricklefs
Keyword(s):  
Range Expansion ◽  
West Indies ◽  
New World ◽  
West Indian ◽  
Historical Biogeography ◽  
Greater Antilles ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
The West ◽  
Sister Relationship

Abstract Solitaires (Myadestes spp.) are montane-forest birds that are widely distributed throughout the New World, ranging from Alaska to northern Bolivia and including both Hawaii and the West Indies. To understand the origins of this impressive distribution, we used five mitochondrial gene sequences to reconstruct the historical biogeography of the genus. The resulting phylogeny indicates a rapid initial spread of the genus to occupy most of its contemporary continental range at least as far south as lower Mesoamerica, plus Hawaii and the Greater Antilles. The North American M. townsendi appears to be the sister taxon of the rest of Myadestes. Myadestes obscurus of Hawaii is more closely allied to Mesoamerican lineages than to M. townsendi. The strongly supported sister relationship of the two West Indian taxa, M. elisabeth and M. genibarbis, indicates a single colonization of the West Indies. A more recent node links the Andean M. ralloides to the Mesoamerican M. melanops and M. coloratus. A standard molecular clock calibration of 2% sequence divergence per million years for avian mitochondrial DNA suggests that the initial diversification of Myadestes occurred near the end of the Miocene (between 5 and 7.5 mya). Cooler temperatures and lower sea levels at that time would have increased the extent of montane forests and reduced overwater dispersal distances, possibly favoring range expansion and colonization of the West Indies. The split between South American and southern Mesoamerican lineages dates to ∼3 mya, which suggests that Myadestes expanded its range to South America soon after the Pliocene rise of the Isthmus of Panama. Despite the demonstrated capacity of Myadestes for long-distance dispersal, several species of Myadestes are highly differentiated geographically. Phylogeographic structure was greatest in the West Indian M. genibarbis, which occurs on several islands in the Greater Antilles and Lesser Antilles, and in the Andean M. ralloides. The phylogeographic differentiation within M. ralloides was not anticipated by previous taxonomic treatments and provides a further example of the importance of the Andes in the diversification of Neotropical birds. Overall, the historical biogeography of Myadestes suggests that range expansion and long-distance dispersal are transient population phases followed by persistent phases of population differentiation and limited dispersal. Biogeografía Histórica de los Zorzales del Género Myadestes

scholarly journals Animal movement drives variation in seed dispersal distance in a plant–animal network

2019 ◽  
Vol 286 (1894) ◽  
pp. 20182007 ◽  
Author(s):  
E. Rehm ◽  
E. Fricke ◽  
J. Bender ◽  
J. Savidge ◽  
H. Rogers
Keyword(s):  
Seed Dispersal ◽  
Animal Movement ◽  
Bird Species ◽  
Dispersal Distance ◽  
Dispersal Patterns ◽  
Long Distance ◽  
Gut Passage ◽  
Dispersal Distances ◽  
Seed Dispersal Distance ◽  
Passage Times

Frugivores play differing roles in shaping dispersal patterns yet seed dispersal distance is rarely quantified across entire communities. We model seed dispersal distance using gut passage times and bird movement for the majority (39 interactions) of known bird–tree interactions on the island of Saipan to highlight differences in seed dispersal distances provided by the five avian frugivores. One bird species was found to be a seed predator rather than a disperser. The remaining four avian species dispersed seeds but differences in seed dispersal distance were largely driven by interspecific variation in bird movement rather than intraspecific variation in gut passage times. The median dispersal distance was at least 56 m for all species-specific combinations, indicating all species play a role in reducing high seed mortality under the parent tree. However, one species—the Micronesian Starling—performed 94% of dispersal events greater than 500 m, suggesting this species could be a key driver of long-distance dispersal services (e.g. linking populations, colonizing new areas). Assessing variation in dispersal patterns across this network highlights key sources of variation in seed dispersal distances and suggests which empirical approaches are sufficient for modelling how seed dispersal mutualisms affect populations and communities.

Long-Distance Seed Dispersal

2018 ◽  
pp. 204-237 ◽  
Author(s):  
Frank M. Schurr ◽  
Orr Spiegel ◽  
Ofer Steinitz ◽  
Ana Trakhtenbrot ◽  
Asaf Tsoar ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Long Distance

Design and development of a sampling platform to study long distance seed dispersal

2014 ◽  
Author(s):  
Jonathan Ogle ◽  
John Naglak ◽  
Isaac Blue-Eyes ◽  
Collin Miller ◽  
Aleph Baumbach ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Design And Development ◽  
Long Distance

Long-distance wind dispersal of tree seeds

1995 ◽  
Vol 73 (7) ◽  
pp. 1036-1045 ◽  
Author(s):  
D. F. Greene ◽  
E. A. Johnson
Keyword(s):  
Seed Dispersal ◽  
Conservation Biology ◽  
Plant Conservation ◽  
Dispersal Distance ◽  
Wind Dispersal ◽  
Source Strength ◽  
Long Distance ◽  
Model Predictions ◽  
Tree Seeds ◽  
The Relationship

Long-distance seed dispersal figures prominently in most plant conservation biology arguments, yet we possess little more than anecdotes concerning the relationship among deposition (seeds/m2), source strength (seeds/m2), and distance. In this paper we derive two simple models for long-distance deposition. The models are tested at the scale of 100–1600 m from the source and found to be within 5-fold of the observed deposition. There is no discernable decline in deposition for the range 300–1600 m. While we hesitate to extend model predictions to greater distances, both the models and the empirical results allow us to assert that rare wind-dispersed species in woodlots (dispersal distance around 1 km) are effectively isolated from one another at the temporal scale of 1000 years. Key words: plant conservation biology, wind dispersal of seeds, metapopulations.

Long-Distance Seed Dispersal

2009 ◽  
pp. 204-237 ◽  
Author(s):  
Frank M. Schurr ◽  
Orr Spiegel ◽  
Ofer Steinitz ◽  
Ana Trakhtenbrot ◽  
Asaf Tsoar ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
Long Distance
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