title: Phylogenetic relationships of Chinese Adiantum based on five plastid markers.
abstract: Adiantum consists of about 150-200 species mostly with a pantropical distribution, yet the classifications of Adiantum have been based primarily on regional studies. Confounding the clarity of reconstructing the evolutionary history of Adiantum is that previous molecular phylogenetic studies suggest that a separate and distinctive clade, the vittarioids, may be derived from within Adiantum. Five plastid markers (atpA, atpB,                         rbcL, trnL-F and rps4-trnS) are employed to assess the monophyly of Adiantum, and construct the molecular phylogeny of Chinese Adiantum. Our analyses support the monophyly of Adiantum. All temperate Adiantum species form a clade nested within the pantropical grade, suggesting a tropical origin of Adiantum. Six main clades are supported within Chinese Adiantum, which are only partially consistent with Lin's classification of the genus. Series Caudata is polyphyletic with series Gravesiana nested within one subgroup of series Caudata. The prolonged whip-like stolon at the apex of the fronds is the defining character for series Caudata, but it may have evolved multiple times. Adiantum reniforme with the simple fronds is sister to series Venusta, which has a decompound lamina with many flabellate to cuneate segments. Series Veneri-capilliformia is not monophyletic, with A. capillus-veneris sister to series Flabellulata except for A. diaphanum, and A. edentulum sister to series Pedata. Series Flabellulata is biphyletic with A. diaphanum nested within the pantropical grade. The phylogeny suggests that convergent evolution in frond architecture has occurred in Adiantum.
authors.affiliation: Laboratory of Plant Biodiversity and Biogeography, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, Yunnan, China. lujinmei@mail.kib.ac.cn
authors.forename: Jin-Mei
authors.initials: JM
authors.lastname: Lu
authors.forename: Jun
authors.initials: J
authors.lastname: Wen
authors.forename: Sue
authors.initials: S
authors.lastname: Lutz
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Wang
authors.forename: De-Zhu
authors.initials: DZ
authors.lastname: Li
mesh_terms: D035681:Adiantum / Q000145:classification* / Q000235:genetics*; D001483:Base Sequence; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D019143:Evolution, Molecular; D005819:Genetic Markers / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D018087:Plastids / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers