title: Historical biogeography of the fern genus Deparia (Athyriaceae) and its relation with polyploidy.
abstract: The wide geographical distribution of many fern species is related to their high dispersal ability. However, very limited studies surveyed biological traits that could contribute to colonization success after dispersal. In this study, we applied phylogenetic approaches to infer historical biogeography of the fern genus Deparia (Athyriaceae, Eupolypods II). Because polyploids are suggested to have better colonization abilities and are abundant in Deparia, we also examined whether polyploidy could be correlated to long-distance dispersal events and whether polyploidy could play a role in these dispersals/establishment and range expansion. Maximum likelihood and Bayesian phylogenetic reconstructions were based on a four-region combined cpDNA dataset (rps16-matK IGS, trnL-L-F, matK and rbcL; a total of 4252 characters) generated from 50 ingroup (ca. 80% of the species diversity) and 13 outgroup taxa. Using the same sequence alignment and maximum likelihood trees, we carried out molecular dating analyses. The resulting chronogram was used to reconstruct ancestral distribution using the DEC model and ancestral ploidy level using ChromEvol. We found that Deparia originated around 27.7Ma in continental Asia/East Asia. A vicariant speciation might account for the disjunctive distribution of East Asia-northeast North America. There were multiple independent long-distance dispersals to Africa/Madagascar (at least once), Southeast Asia (at least once), south Pacific islands (at least twice), Australia/New Guinea/New Zealand (at least once), and the Hawaiian Islands (at least once). In particular, the long-distance dispersal to the Hawaiian Islands was associated with polyploidization, and the dispersal rate was slightly higher in the polyploids than in diploids. Moreover, we found five species showing recent infraspecific range expansions, all of which took place concurrently with polyploidization. In conclusion, our study provides the first investigation using phylogenetic and biogeographic analyses trying to explore the link between historical biogeography and ploidy evolution in a fern genus and our results imply that polyploids might be better colonizers than diploids.
authors: Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei 10617, Taiwan. Electronic address: salvinia@hotmail.com.
authors: Li-Yaung
authors: LY
authors: Kuo
authors: Department of Botany, National Museum of Nature and Science, Amakubo 4-1-1, Tsukuba, Ibaraki 305-0005, Japan.
authors: Atsushi
authors: A
authors: Ebihara
authors: Faculty of Education, Kagawa University, Saiwaicho 1-1, Takamatsu, Kagawa 760-8522, Japan.
authors: Wataru
authors: W
authors: Shinohara
authors: Muséum national d'Histoire naturelle, Institut de Systématique, Evolution, Biodiversité (UMR 7205 CNRS, MNHN, UPMC, EPHE), Herbier National, 16 rue Buffon CP39, F-75005 Paris, France.
authors: Germinal
authors: G
authors: Rouhan
authors: National Tropical Botanical Garden, Kauai, Kalaheo, HI 96741, USA.
authors: Kenneth R
authors: KR
authors: Wood
authors: Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei 10617, Taiwan; Department of Life Science, National Taiwan University, Taipei 10617, Taiwan. Electronic address: leafy@ntu.edu.tw.
authors: Chun-Neng
authors: CN
authors: Wang
authors: Division of Botanical Garden, Taiwan Forestry Research Institute, Taipei 10066, Taiwan; Dr. Cecilia Koo Botanic Conservation Center, Pingtung County 906, Taiwan. Electronic address: chiouwl@gmail.com.
authors: Wen-Liang
authors: WL
authors: Chiou
mesh_terms: D000349:Africa; D001208:Asia; D001315:Australia; D001499:Bayes Theorem; D044822:Biodiversity; D056931:Cryptochromes / Q000145:classification / Q000235:genetics / Q000378:metabolism; D018742:DNA, Chloroplast / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029624:Ferns / Q000145:classification* / Q000235:genetics; D006254:Hawaii; D009656:North America; D010802:Phylogeny; D058974:Phylogeography; D011123:Polyploidy; D017422:Sequence Analysis, DNA
chemical_list: D056931:Cryptochromes; D018742:DNA, Chloroplast
keywords: Athyriaceae; Biogeography; Deparia; Ferns; Long-distance dispersal; Polyploid