Titel:
mechanisms of speciation in SE Asian ant plants of the genus Macaranga (Euphorbiaceae)
Projektleitung an der Universität Würzburg:
Beteiligte Wissenschaftlerinnen und Wissenschaftler:
Kurzbeschreibung:
We are investigating the influence of ant partners on speciation processes in the ant-plant (= myrmecophytic) genus Macaranga. Based on previous work, we hypothesize that the obligatory symbiosis with ants may reduce gene flow among plant populations, eventually resulting in allopatric speciation. First attempts to test this hypothesis by reconstructing phylogeographic networks based on chloroplast DNA (cpDNA) variation provided evidence for hybridization and cpDNA introgression among closely related Macaranga species. An extended chloroplast genealogy comprising 41 Macaranga species clearly showed that gene flow is restricted to the sectional level in sect. Pruinosae, and to the level of subsectional groups in sect. Pachystemon. In the next application period, we will further test the hypothesis of allopatric speciation by (1) seedling transplantation experiments aimed at estimating maximum colonization distances of the ant partners, (2) population genetic experiments of three separate (sub)sectional groups of Macaranga species to elucidate the extent of population differentiation within myrmecophytic vs. non-myrmecophytes species, the extent of nuclear and cytoplasmic gene flow between species, and the relative influence of seed and pollen flow at the populational, local and regional scale in NE Borneo, and (3) reconstructing phylogeographic networks of each of the three investigated Macaranga groups as well as their ant partners in the same region.
Laufzeit: von 05.2006 bis 04.2008
Förderinstitution:
DFG ( Sachbeihilfe ) ,Genehmigungsdatum: 19.01.06
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