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Towards a global perspective for Salvia L.: Phylogeny,diversification and floral evolution |
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| Authors: | Fatemeh Moein Ziba Jamzad Mohammadreza Rahiminejad Jacob B. Landis Mansour Mirtadzadini Douglas E. Soltis Pamela S. Soltis |
| Affiliation: | 1. Department of Plant and Animal Biology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran;2. Department of Botany, Research Institute of Forest and Rangelands, Tehran, Iran Contribution: Conceptualization (equal), Resources (equal), Supervision (equal), Writing - review & editing (equal);3. Department of Plant and Animal Biology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran Contribution: Conceptualization (supporting), Supervision (equal);4. School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Cornell University, Ithaca, New York, USA BTI Computational Biology Center, Boyce Thompson Institute, Ithaca, New York, USA Contribution: Conceptualization (supporting), Formal analysis (supporting), Methodology (supporting), Validation (supporting), Writing - review & editing (equal);5. Department of Biology, Faculty of Science, Shahid Bahonar Univ., Kerman, Iran Contribution: Data curation (equal), Resources (equal);6. Department of Biology, University of Florida, Gainesville, Florida, USA;7. Florida Museum of Natural History, University of Florida, Gainesville, Florida, USA The Genetics Institute, University of Florida, Gainesville, Florida, USA The Biodiversity Institute, University of Florida, Gainesville, Florida, USA Contribution: Conceptualization (equal), Funding acquisition (equal), Project administration (equal), Supervision (equal), Writing - review & editing (equal) |
| Abstract: | Salvia is the most species-rich genus in Lamiaceae, encompassing approximately 1000 species distributed all over the world. We sought a new evolutionary perspective for Salvia by employing macroevolutionary analyses to address the tempo and mode of diversification. To study the association of floral traits with speciation and extinction, we modelled and explored the evolution of corolla length and the lever-mechanism pollination system across our Salvia phylogeny. We reconstructed a multigene phylogeny for 366 species of Salvia in the broad sense including all major recognized lineages and 50 species from Iran, a region previously overlooked in studies of the genus. Our comprehensive sampling of Iranian species of Salvia provides higher phylogenetic resolution for southwestern Asian species than obtained in previous studies. Our phylogenetic data in combination with divergence time estimates were used to examine the evolution of corolla length, woody versus herbaceous habit, and presence versus absence of a lever mechanism. We investigated the timing and dependence of Salvia diversification related to corolla length evolution through a disparity test and BAMM analysis. A HiSSE model was used to evaluate the dependency of diversification on the lever-mechanism pollination system in Salvia. A medium corolla length (15–18 mm) was reconstructed as the ancestral state for Salvia with multiple shifts to shorter and longer corollas. Macroevolutionary model analyses indicate that corolla length disparity is high throughout Salvia evolution, significantly different from expectations under a Brownian motion model during the last 28 million years of evolution. Our analyses show evidence of a higher diversification rate of corolla length for some Andean species of Salvia compared to other members of the genus. Based on our tests of diversification models, we reject the hypothesis of a direct effect of the lever mechanism on Salvia diversification. Therefore, we suggest caution in considering the lever-mechanism pollination system as one of the main drivers of speciation in Salvia. |
| Keywords: | corolla diversification lever mechanism phylogeny pollination Salvia . |