Description: Das Projekt "Evolution of plant morphological diversity in plant-insect mutualisms" wird vom Umweltbundesamt gefördert und von Universität Zürich, Institut für Pflanzenbiologie durchgeführt. Most plants rely on insects for their pollination, protection (e.g., from herbivores) and/or seed dispersal, and have formed a mutually beneficial interaction, or mutualism. The current research investigates the evolution of plant traits involved in plant-insect mutualisms. In particular, it focuses on the evolution of extrafloral nectaries (EFNs): secretory structures on plant parts outside the flower, which offer carbohydrate-rich, water-based secretions (=nectar) to ants in return for their protection from herbivores (i.e. protective mutualisms). EFNs occur in some ferns and over hundred families of flowering plants, especially the legume family. However, their phylogenetic distribution within families, morphological diversity and evolution, and evolutionary role are poorly understood. Also EFN plant-ant interactions are known to shape entire tropical and savannah-like ecosystems, but their unexpected occurrence in deserts - where plants need to manage water carefully - has been studied only in a few cacti. This study investigated the diversity and evolution of EFNs at three different levels: (1) in the Leguminosae, the third largest and second economically most important angiosperm family, which also dominates many kinds of vegetation worldwide; (2) in the legume genus Senna, a case study where EFNs represent a key innovation (see past SNF project by B. Marazzi); and (3) in Sonoran Desert plants. Current results show that EFNs occur in species of over 130 legume genera (over twice as many as in the last published account of EFNs in this family). They are particularly abundant in the subfamily Mimosoideae, and may have evolved independently at least 30 times in the family. This incredible number of origins suggests the action of some evolutionary (perhaps genetic) precursor that allowed some clades to evolve EFNs more 'easily' given ceartin selective regimes. Most legume EFNs occur on the (typically pinnate) leaves, less often on stipules and different parts of inflorescences. In Senna, ancestral leaf EFNs appear to have evolved first between the proximal pair of leaflets only (some 40 Million years ago), and later also between the other pairs of leaflets (several times) or only at the base of the leaf stalk (once). In the Sonoran Desert area (including also mountain habitats), EFNs may occur in species from up to 32 families, in several cacti and in particular Leguminosae, dominant in this vegetation. EFNs have apparently been reduced but have been retained in a functional state (i.e., secreting nectar) in most desert legumes, and are thus capable of participating in protective mutualisms with desert ants. This research shows that EFNs are more widespread in plants than previously thought, suggesting that we may have underestimated the role of protective ant-plant interactions in shaping ecosystem ecology and evolution
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Ameise ? Insekt ? Pflanzenökologie ? Vegetation ? Zierpflanze ? Zürich ? Befruchtung ? Botanik ? Buchhaltung ? Farn ? Genetik ? Leguminosen ? Ökologie ? Pflanzensamen ? Bestäubung ? Bedecktsamer ? Pflanzenvielfalt ? Habitat ? Kind ? Laubblatt ? Tropisches Ökosystem ? Diversifikation ? Blüte ? Gebäude ? Blütenpflanze ? Vorläufersubstanz ? Innovation ? Berg ? Bewässerung ? Evolution ? Studie ? Tropengebiet ? Fallstudie ? Wüste ? Familie ? Pflanze ? Wasser ? Ökosystemforschung ? Rechtsverfahren ? Anpassung ? Ökosystem ? Bedarf ? Gebirge ? Staat ? Forschung ? Basen [chemisch] ? See [Binnengewässer] ? TEIL ? VERTEILUNG ? WICHTIG ? Wechselwirkung ? ant-plant interaction ? desert plants ? Bepflanzung ? Diversität ? ERGEBNIS ? EVOLUTIONAER ? FAEHIG ? FORMBLAETTER ? LAENDER ? Laub ? MERKBLAETTER ? MERKBLATT ? PROJEKT ? SCHUTZ ? Art [Spezies] ? SELEKTIV ? SONSTIG ? Savanne ?
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2009-10-01 - 2011-03-31
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