Neo- and Paleopolyploidy contribute to the species diversity of Asplenium the most species-rich genus of ferns  

作　　者：Harald Schneider Hong-Mei Liu Yan-Fen Chang Daniel Ohlsen Leon R. Perrie Lara Shepherd Michael Kessler Dirk N. Karger Sabine Hennequin Jeannine Marquardt Stephen Russell Stephen Ansell Ngan Thi Lu Peris Kamau Josmaily Loriga Ledis Regalado Jochen Heinrichs Atsushi Ebihara Alan R. Smith Mary Gibby 

机构地区：[1]Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China [2]Department of Life Sciences, Natural History Museum, London SW7 5BD, UK [3]School of Botany, The University of Melbourne, Melbourne, Victoria 3010, Australia [4]Museum of New Zealand Te Papa Tongarewa, P.O. Box 467, Wellington 6140, New Zealand [5]Institute of Systematic Botany, University of Zurich, 8008 Zurich, Switzerland [6]Dynamic Macroecology Group, Swiss Federal Research Institute WSL, 8903 Birmsersdorf, Switzerland [7]Institute de Systematique, Evolution, Biodiversite, Universite Pierre et Marie Curie, 75005 Paris, France [8]Department of Botany, Vietnam National Museum of Nature, Vietnam Academy of Science and Technology, Ha Noi, Vietnam [9]Botany Department, National Museums of Kenya, PO Box 40058-00100 Nairobi, Kenya [10]University of Munich (LMU), Department of Biology I, Systematic Botany and Mycology, Geobio-Center, 80638 Munich, Germany [11]Instituto de Ecologia y Sistematica, Carretera de Varona 11835 e/Oriente y Lindero, La Habana 19, CP 11900, Calabazar, Boyeros, La Habana, Cuba [12]Department of Botany, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba 305-0005, Japan [13]University Herbarium, University of California, Berkeley, CA 9472o, USA [14]Royal Botanic Garden Edinburgh, Edinburgh EH3 5LR, UK

出　　处：《Journal of Systematics and Evolution》2017年第4期353-364,共12页植物分类学报（英文版）

摘　　要：Polyploidy is widely considered as a major process in the evolution of plants but the accumulation of polyploid species diversity is still controversial. Some recent studies proposed increased extinction risk in neopolyploids compared with their diploid ancestors. The high proportion of polyploid ferns is expected to be formed mainly by neopolyploids, whereas paleopolyploid species are predicted to be clustered in clades founded by whole genome duplications. Here, we test this prediction by exploring the evolution of polyploidy in the derived fern family Aspleniaceae. The family has a global distribution and shows the highest frequency of polyploid taxa among all ferns. To test the hypothesis, we obtained a comprehensive phylogeny using chloroplast DNA sequences of 883 specimens representing 292 species. All published chromosome counts were mapped onto this phylogenetic framework in order to explore the evolution of polyploids. We recovered evidence for several whole genome duplications in the history of Aspleniaceae. Phylogenetic relationships of polyploids exceeding the tetraploid level suggest that tetraploid Asplenium species may have replaced their diploid ancestors as the main evolutionary players in some clades of this family.Polyploidy is widely considered as a major process in the evolution of plants but the accumulation of polyploid species diversity is still controversial. Some recent studies proposed increased extinction risk in neopolyploids compared with their diploid ancestors. The high proportion of polyploid ferns is expected to be formed mainly by neopolyploids, whereas paleopolyploid species are predicted to be clustered in clades founded by whole genome duplications. Here, we test this prediction by exploring the evolution of polyploidy in the derived fern family Aspleniaceae. The family has a global distribution and shows the highest frequency of polyploid taxa among all ferns. To test the hypothesis, we obtained a comprehensive phylogeny using chloroplast DNA sequences of 883 specimens representing 292 species. All published chromosome counts were mapped onto this phylogenetic framework in order to explore the evolution of polyploids. We recovered evidence for several whole genome duplications in the history of Aspleniaceae. Phylogenetic relationships of polyploids exceeding the tetraploid level suggest that tetraploid Asplenium species may have replaced their diploid ancestors as the main evolutionary players in some clades of this family.

关 键 词：chromosome number DIVERSIFICATION extinction risk genome evolution MACROEVOLUTION neopolyploidypaleopolyploidy. 

分 类 号：Q949.36[生物学—植物学] S718.54[农业科学—林学]