Recurrent allopolyploidizations diversify ecophysiological traits in marsh orchids (Dactylorhiza majalis s.l.)

Thomas M Wolfe, Francisco Balao, Emiliano Trucchi, Gert Bachmann, Wenjia Gu, Juliane Baar, Mikael Hedrén, Wolfram Weckwerth, Andrew R Leitch, Ovidiu Paun

Whole-genome duplication has shaped the evolution of angiosperms and other organisms, and is important for many crops. Structural reorganization of chromosomes and repatterning of gene expression are frequently observed in allopolyploids, with physiological and ecological consequences. Recurrent origins from different parental populations are widespread among polyploids, resulting in an array of lineages that provide excellent models to uncover mechanisms of adaptation to divergent environments in early phases of polyploid evolution. We integrate here transcriptomic and ecophysiological comparative studies to show that sibling allopolyploid marsh orchid species (Dactylorhiza, Orchidaceae) occur in different habitats (low nutrient fens vs. meadows with mesic soils) and are characterized by a complex suite of intertwined, pronounced ecophysiological differences between them. We uncover distinct features in leaf elemental chemistry, light-harvesting, photoprotection, nutrient transport and stomata activity of the two sibling allopolyploids, which appear to match their specific ecologies, in particular soil chemistry differences at their native sites. We argue that the phenotypic divergence between the sibling allopolyploids has a clear genetic basis, generating ecological barriers that maintain distinct, independent lineages, despite pervasive interspecific gene flow. This suggests that recurrent origins of polyploids bring about a long-term potential to trigger and maintain functional and ecological diversity in marsh orchids and other groups.

Department of Botany and Biodiversity Research, Functional and Evolutionary Ecology
External organisation(s)
Vienna Graduate School of Population Genetics, Universität für Bodenkultur Wien, Universidad de Sevilla, Università Politecnica delle Marche, Queen Mary University of London, Lund University, Universität Wien
Molecular Ecology
No. of pages
Publication date
Peer reviewed
Austrian Fields of Science 2012
106003 Biodiversity research, 106014 Genomics, 106030 Plant ecology
ASJC Scopus subject areas
Genetics, Ecology, Evolution, Behavior and Systematics
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