African origin and global distribution patterns: Evidence inferred from phylogenetic and biogeographical analyses of ectomycorrhizal fungal genus Strobilomyces |
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| Authors: | Li H Han Bang Feng Gang Wu Roy E Halling Bart Buyck Nourou S Yorou Sydney T N Ebika Zhu L Yang |
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| Affiliation: | 1. Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China;2. Key Laboratory of Yunnan Province Universities of the Diversity and Ecological Adaptive Evolution for Animals and Plants on Yungui Plateau, Qujing Normal University, Qujing, Yunnan, China;3. University of Chinese Academy of Sciences, Beijing, China;4. Institute of Systematic Botany, New York Botanical Garden, Bronx, NY, USA;5. Département Systématique et Evolution, Muséum National d'Histoire Naturelle, USM Taxonomie et Collections (CP 39), Paris Cedex 05, France;6. Faculty of Agronomy, University of Parakou, Parakou, Benin;7. Initiative des Champignons et des Plantes du Congo, Brazzaville, Republic of Congo |
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| Abstract: | Aim The ectomycorrhizal genus Strobilomyces is widely distributed throughout many parts of the world, but its origin, divergence and distribution patterns remain largely unresolved. In this study, we aim to explore the species diversity, distribution and evolutionary patterns of Strobilomyces on a global scale by establishing a general phylogenetic framework with extensive sampling. Location Africa, Australasia, East Asia, Europe, North America, Central America and Southeast Asia. Methods The genealogical concordance phylogenetic species recognition method was used to delimit phylogenetic species. Divergence times were estimated using a Bayesian uncorrelated lognormal relaxed molecular clock. The ancestral area and host of Strobilomyces were inferred via the programs rasp and mesquite . The change of diversification rate over time was estimated using Ape, Laser and Bammtools software packages. Results We recognize a novel African clade and 49 phylogenetic species with morphological evidence, including 18 new phylogenetic species and 23 previously described ones. Strobilomyces probably originated in Africa, in association with Detarioideae/Phyllanthaceae/Monotoideae during the early Eocene. The dispersal to Southeast Asia can be explained by Wolfe's “Boreotropical migration” hypothesis. East Asia, Australasia, Europe and North/Central America are primarily the recipients of immigrant taxa during the Oligocene or later. A rapid radiation implied by one diversification shift was inferred within Strobilomyces during the Miocene. Main conclusions An unexpected phylogenetic species diversity within Strobilomyces was uncovered. The highest diversity, resulting probably from a rapid radiation, was found in East Asia. Dispersal played an important role in the current distribution pattern of Strobilomyces. The Palaeotropical disjunction is explained by species dispersal from Africa to Southeast Asia through boreotropical forests during the early Eocene. Species from the Northern Hemisphere and Australasia are largely derived from immigrant ancestors from Southeast Asia. |
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| Keywords: | biogeography boreotropics dispersal molecular clock palaeotropic disjunction phylogenetic species vicariance |
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