Project

Back to overview

Pollinator-driven evolution in different pollination systems

English title Pollinator-driven evolution in different pollination systems
Applicant Schiestl Florian P.
Number 125340
Funding scheme Project funding
Research institution Institut für Systematische Botanik und Botanischer Garten Universität Zürich
Institution of higher education University of Zurich - ZH
Main discipline Botany
Start/End 01.11.2009 - 31.10.2013
Approved amount 458'840.00
Show all

All Disciplines (2)

Discipline
Botany
Molecular Biology

Keywords (10)

pollination; orchids; sexual deception; density-dependent selection; local adaptation; pollinator mosaic; selection; floral evolution; reproductive success; floral scent

Lay Summary (English)

Lead
Lay summary
Plants often need pollinators to transfer their gametes during sexual reproduction. Because pollinators have specific preferences for signals (color, scent) and morphology, they select for certain floral traits. Such pollinator-mediated selection can be measured through connecting reproductive success (e.g. fruit set) with the floral characters a plant produces. Since pollinator faunas vary on a geographical scale, e.g. due to climatic factors in different altitudinal ranges, regional differences in selection for floral traits is expected, leading to the adaptation of plants to a landscape "pollinator mosaic". Adaptation to regional differences in pollinators can result in isolation, and the formation of different species as a consequence. The here proposed research strives to examine different mechanism of pollinator-mediated evolution in plants. The proposed experiments will be done comparatively in two different pollination systems, namely food reward and sexual deception within the subtribe Orchidinae (Orchidaceae). Sexual deception involves the imitation of mating signals by flowers and pollination by sexually aroused male pollinators. The comparative approach is chosen to acknowledge the likely differences of evolutionary mechanisms among plants with different pollination systems. To test for local adaptation, plants will be transferred among populations and reproductive success compared to local control plants. Floral traits (morphology, color, scent) will be measured in the study populations. Selection on floral traits will be examined in local and transferred plants. Additionally, odor genes will be sequenced and patterns of variability compared with neutral markers, within and among populations. Selection dynamics in relation to population densities will be examined in plot experiments by manipulating population densities and monitoring reproductive success. The here proposed research is a comprehensive and novel approach to pollinator-driven evolution in plants. The multi-population setting will shed light on the microevolutionary processes, i.e. local adaptation and selection dynamics that underlie the astonishing floral diversity found within and among plant species. Environmental change is expected to impact on plants and their biotic interactions, through change in pollinator faunas and thus selective environment for reproductive traits. The combination of lowland (warm) and alpine (cold) habitats in this study will add insights into how climatic changes can impact on plant pollinator interactions. The assessment of variability in adaptive genes will provide insight into the adaptability of populations for the respective traits
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Why Do Floral Perfumes Become Different? Region-Specific Selection on Floral Scent in a Terrestrial Orchid
Gross Karin Sun Mimi Schiestl P. Florian (2016), Why Do Floral Perfumes Become Different? Region-Specific Selection on Floral Scent in a Terrestrial Orchid, in Plos One, 11(2), e0147975.
Are tetraploids more successful? Floral signals, reproductive success and floral isolation in mixed-ploidy populations of a terrestrial orchid
Gross Karin Schiestl Florian (2015), Are tetraploids more successful? Floral signals, reproductive success and floral isolation in mixed-ploidy populations of a terrestrial orchid, in Annals of Botany, 115(2), 135-143.
Floral isolation is the major reproductive barrier between a pair of rewarding orchid sister species
Sun Mimi Schlüter Philipp Gross Karin Schiestl P. Florian (2015), Floral isolation is the major reproductive barrier between a pair of rewarding orchid sister species, in Journal of Evolutionary Biology, 28(1), 117-129.
Floral adaptation to local pollinator guilds in a terrestrial orchid
Sun Mimi, Gross Karin, Schiestl Florian (2014), Floral adaptation to local pollinator guilds in a terrestrial orchid, in Annals of Botany, 113(2), 289-300.

Collaboration

Group / person Country
Types of collaboration
Salvatore Cozzolino Italy (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Associated projects

Number Title Start Funding scheme
137058 Plant Reproductive Isolation: from Mechanisms to Evolution 01.01.2012 ProDoc
134416 InvaVol: What are the consequences of herbivore attack for floral signals? 01.04.2011 Project funding (special)
112342 Evolutionary ecology of floral signals and pollinator specificity in plants 01.06.2006 Project funding
130796 The molecular basis of floral traits underlying reproductive isolation in sexually deceptive orchids 01.11.2010 Project funding

Abstract

Pollinators influence plant evolution through their essential role of transferring gametes. Pollinators select for certain floral traits, and can also isolate plant lineages through assortative visitation. Since pollinator faunas vary on a geographical scale, e.g. due to climatic factors in different altitudinal ranges, regional differences in selection for floral traits is expected, leading to the adaptation of plants to a landscape “pollinator mosaic”. Adaptation to regional differences in pollinators can result in reproductive isolation, and hence allopatric speciation. As an alternative scenario, adaptation to new pollinators can evolve in sympatry, under density-dependent selection, or as a secondary outcome of polyploidisation and selection for pre-pollination isolation. The here proposed research strives to examine different mechanism of pollinator-mediated evolution in plants, by investigating: 1) plant adaptation to a pollinator mosaic and population specific selection on floral traits, 2) density-dependent selection and the adaptation to new pollinators, and 3) the influence of polyploidisation on the evolution of floral signals. The proposed experiments will be done comparatively in two different pollination systems, namely food reward and sexual deception within the subtribe Orchidinae (Orchidaceae). The comparative approach is chosen to acknowledge the likely differences of evolutionary mechanisms among plants with different pollination systems. To examine adaptation to the pollinator mosaic, pollinator guilds will be determined in populations at different altitudes, from lowland to alpine habitats. To test for local adaptation, plants will be transferred among populations and reproductive success compared to local control plants. Floral traits (morphology, color, scent) and ploidy level will be measured in the study populations. Phenotypic selection on floral traits will be examined in local and transferred plants by regressing relative pollination success and pollinia removal on different floral traits. Additionally, odor genes will be sequenced and patterns of variability compared with neutral markers, within and among populations. Selection dynamics in relation to population densities will be examined in plot experiments by manipulating population densities and monitoring reproductive success. To investigate if polyploidisation drives the divergence in floral signals, various floral traits of plants will be compared among individuals with different ploidy level. The here proposed research is a comprehensive and novel approach to pollinator-driven evolution in plants. The multi-population setting will shed light on the microevolutionary processes, i.e. local adaptation and selection dynamics that underlie the astonishing floral diversity found within and among plant species. The assessment of selection on floral traits and their underlying genes (for floral odor) will illustrate how pollinators can cause change on floral traits. Environmental change is expected to impact on plants and their biotic interactions, through change in pollinator faunas and thus selective environment for reproductive traits. The combination of lowland (warm) and alpine (cold) habitats in this study will add insights into how climatic changes can impact on plant pollinator interactions. The assessment of variability in adaptive genes will provide insight into the adaptability of populations for the respective traits.
-