scholarly journals Escape from extreme specialization: passionflowers, bats and the sword-billed hummingbird

2014 ◽  
Vol 281 (1795) ◽  
pp. 20140888 ◽  
Author(s):  
S. Abrahamczyk ◽  
D. Souto-Vilarós ◽  
S. S. Renner

A striking example of plant/pollinator trait matching is found between Andean species of Passiflora with 6–14-cm-long nectar tubes and the sword-billed hummingbird, Ensifera ensifera , with up to 11-cm-long bills. Because of the position of their anthers and stigmas, and self-incompatibility, these passionflower species depend on E. ensifera for pollination. Field observations show that the bird and plant distribution match completely and that scarcity of Ensifera results in reduced passionflower seed set. We here use nuclear and plastid DNA sequences to investigate how often and when these mutualisms evolved and under which conditions, if ever, they were lost. The phylogeny includes 26 (70%) of the 37 extremely long-tubed species, 13 (68%) of the 19 species with tubes too short for Ensifera and four of the seven bat-pollinated species for a total of 43 (69%) of all species in Passiflora supersection Tacsonia (plus 11 outgroups). We time-calibrated the phylogeny to infer the speed of any pollinator switching. Results show that Tacsonia is monophyletic and that its stem group dates to 10.7 Ma, matching the divergence at 11.6 Ma of E. ensifera from its short-billed sister species. Whether pollination by short-billed hummingbirds or by Ensifera is the ancestral condition cannot be securely inferred, but extremely long-tubed flowers exclusively pollinated by Ensifera evolved early during the radiation of the Tacsonia clade. There is also evidence of several losses of Ensifera dependence, involving shifts to bat pollination and shorter billed birds. Besides being extremely asymmetric—a single bird species coevolving with a speciose plant clade—the Ensifera / Passiflora system is a prime example of a specialized pollinator not driving plant speciation, but instead being the precondition for the maintenance of isolated populations (through reliable seed set) that then underwent allopatric speciation.

Diversity ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 5
Author(s):  
Herbert Braunschmid ◽  
Robin Guilhot ◽  
Stefan Dötterl

Floral scent is an important trait in plant–pollinator interactions. It not only varies among plant species but also among populations within species. Such variability might be caused by various non–selective factors, or, as has been shown in some instances, might be the result of divergent selective pressures exerted by variable pollinator climates. Cypripedium calceolus is a Eurasian deceptive orchid pollinated mainly by bees, which spans wide altitudinal and latitudinal gradients in mainly quite isolated populations. In the present study, we investigated whether pollinators and floral scents vary among different latitudes. Floral scents of three C. calceolus populations in the Southern Alps were collected by dynamic headspace and analyzed by gas chromatography coupled to mass spectrometry (GC/MS). These data were completed by previously published scent data of the Northern Alps and Scandinavia. The scent characteristics were compared with information on pollinators recorded for present study or available in the literature. More than 80 scent compounds were overall recorded from plants of the three regions, mainly aliphatics, terpenoids, and aromatics. Seven compounds were found in all samples, and most samples were dominated by linalool and octyl acetate. Although scents differed among regions and populations, the main compounds were similar among regions. Andrena and Lasioglossum species were the main pollinators in all three regions, with Andrena being relatively more abundant than Lasioglossum in Scandinavia. We discuss natural selection mediated by pollinators and negative frequency–dependent selection as possible reasons for the identified variation of floral scent within and among populations and regions.


Heredity ◽  
1983 ◽  
Vol 50 (2) ◽  
pp. 169-177 ◽  
Author(s):  
C H Fearon ◽  
M D Hayward ◽  
M J Lawrence

2009 ◽  
Vol 47 (5) ◽  
pp. 402-415 ◽  
Author(s):  
Ji-Pei YUE ◽  
Hang SUN ◽  
David A. BAUM ◽  
Jian-Hua LI ◽  
Ihsan A. AL-SHEHBAZ ◽  
...  

2020 ◽  
Vol 51 (1) ◽  
pp. 319-340
Author(s):  
Amanda D. Benoit ◽  
Susan Kalisz

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.


2020 ◽  
Vol 194 (1) ◽  
pp. 84-99
Author(s):  
Inelia Escobar ◽  
Eduardo Ruiz-Ponce ◽  
Paula J Rudall ◽  
Michael F Fay ◽  
Oscar Toro-Núñez ◽  
...  

Abstract Gilliesieae are a South American tribe of Amaryllidaceae characterized by high floral diversity. Given different taxonomic interpretations and proposals for generic and specific relationships, a representative phylogenetic analysis is required to clarify the systematics of this group. The present study provides a framework for understanding phylogenetic relationships and contributing to the development of an appropriate taxonomic treatment of Gilliesieae. Molecular analyses, based on nuclear (ITS) and plastid DNA sequences (trnL-F and rbcL), resolve with strong support the monophyly of the tribe and the differentiation of two major clades. Clade I comprises the genera Gilliesia, Gethyum and Solaria and Clade II includes Miersia and Speea. These well-supported clades are mostly congruent with vegetative and karyotype characters rather than, e.g., floral symmetry. At the generic level, all molecular analyses reveal the paraphyly of Gilliesia and Miersia. Gethyum was found to be paraphyletic, resulting in the confirmation of Ancrumia as a distinct genus. Several instances of incongruent phylogenetic signals were found among data sets. The calibrated tree suggests a recent diversification of the tribe (Pliocene–Pleistocene), a contemporary process of speciation in which instances of hybridization and incomplete lineage sorting could explain patterns of paraphyly and incongruence of floral morphology.


2005 ◽  
Vol 166 (2) ◽  
pp. 289-300 ◽  
Author(s):  
Larry Hufford ◽  
Michelle M. McMahon ◽  
Robin O’Quinn ◽  
Muriel E. Poston

1980 ◽  
Vol 58 (6) ◽  
pp. 712-716 ◽  
Author(s):  
Shirley Dobrofsky ◽  
W. F. Grant

Self-incompatibility, a prefertilization event, and self-sterility, a postfertilization event, have both been suggested as causes for differences in seed set between cross- and self-pollinated florets in Lotus corniculatus L. Ovary protein subunits of selfed, crossed, and unpollinated florets of L. corniculatus cv. Mirabel were studied using polyacrylamide gel electrophoresis. Banding patterns differed for all three conditions. Ovary protein differences were found prior to the time fertilization is known to occur, thereby providing evidence that self-incompatibility is at least partially responsible for the reduced seed set after self-pollination.


2019 ◽  
Vol 190 (4) ◽  
pp. 389-404 ◽  
Author(s):  
Kálmán Könyves ◽  
John David ◽  
Alastair Culham

Abstract Hoop-petticoat daffodils are a morphologically congruent group comprised of two distinct lineages in molecular phylogenetic trees of Narcissus. It is possible that the morphological similarity is a product of both historic and current low-level gene flow between these lineages. For the first time, we report population sampling from across the entire range of distribution covering the Iberian Peninsula and Morocco. In total, 455 samples were collected from 59 populations. Plastid DNA sequences of matK and ndhF were generated alongside 11 microsatellite loci to permit comparison between plastid and nuclear lineage histories. The plastid DNA phylogenetic tree was highly congruent with previous molecular studies and supported the recognition of these two lineages of hoop-petticoat daffodils as separate sections. Assignment of samples to sections sometimes differed between plastid DNA and (nuclear) microsatellite data. In these cases, the taxa had previously been the focus of dissent in taxonomic placement based on morphology. These discrepancies could be explained by hybridization and introgression among the two lineages during the evolution of hoop-petticoat daffodils, and shows that placement of species in sections is dependent on the source of data used. This study underlines the complex evolutionary history of Narcissus and highlights the discrepancies between floral morphology and phylogeny, which provides a continuing challenge for the systematics of Narcissus.


Phytotaxa ◽  
2019 ◽  
Vol 419 (1) ◽  
pp. 39-62 ◽  
Author(s):  
PAUL B. HAMILTON ◽  
AMANDA M. SAVOIE ◽  
CYNTHIA M. SAYRE ◽  
OLIVER SKIBBE ◽  
JONAS ZIMMERMANN ◽  
...  

Five taxa in the genus Neidium, N. iridis, N. beatyi sp. nov., N. vandusenense sp. nov., N. collare sp. nov. and N. lavoieanum sp. nov. are documented from a pond and stream system in the VanDusen Botanical Garden, Vancouver, Canada. Neidium beatyi is a large linear species with multiple longitudinal canals and sagittate apices. The areolae are occluded by finger-like silica extensions on the external surface. This taxon is distinguished from Neidium iridis by the number of longitudinal canals (>5), shape of the valve apices, and smaller size. Neidium vandusenense is broadly linear with distinct rostrate apices. Two-three longitudinal canals are present along each margin. Plastid rbcL sequence data associates this taxon with N. amphigomphus. Neidium collare is an elliptic lanceolate taxon with one longitudinal canal. This taxon is genetically related to N. bisculatum sensu lato, but with a different shape form. Neidium lavoieanum has a valve shape form similar to Neidium potapovae, but is larger and genetically similar to N. productum sensu lato. The five Neidium taxa were observed in a small stream next to Lake Victoria (pond) in the VanDusen Botanical Garden Vancouver, Canada. The water was mildly alkaline with a pH of 7.86, a conductance of 163 µS/cm, higher nutrient loads and low metal content.


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