title: Molecular systematics of the fern genus Hymenophyllum s.l. (Hymenophyllaceae) based on chloroplastic coding and noncoding regions.
abstract: We investigated the phylogenetic relationships of the filmy fern genus Hymenophyllum s.l. using the rbcL and rps4 genes and the intergenic spacer rps4-trnS. Because of variation in length of the noncoding marker, we tested and compared three methods for integrating indels. They proved to be useful for estimating a phylogeny of the genus. The rps4-trnS marker, with coded indels integrated, produced better resolution than analysis of either rps4 or rbcL, and combining the three data sets allowed us to obtain a well resolved and strongly supported topology. We interpret our data as showing support for the classical bigeneric system for the family, and call into question several classifications proposed in the past century. The segregate genera Cardiomanes, Hymenoglossum, Serpyllopsis, and Rosenstockia are embedded within Hymenophyllum s.l. Although the deepest relationships within the genus remain uncertain, two subgenera described by Morton do have some support: (1) Sphaerocionium, in which the problematic section Microtrichomanes is embedded; and (2) a diverse Hymenophyllum, including species that were placed originally in Serpyllopsis, Rosenstockia, Hemicyatheon, and Craspedophyllum by Copeland. Subgenus Mecodium appears to be polyphyletic; nevertheless, a subgroup within Mecodium is strongly supported. Several unexpected associations gain support from cytological data and certain morphological characters not previously used to distinguish species groups within Hymenophyllum s.l.
authors.affiliation: Laboratoire de Paléobotanique et Paléoécologie, Université Pierre et Marie Curie et IFR 101 CNRS, 75005, Paris, France. sabine.hennequin@snv.jussieu.fr
authors.forename: Sabine
authors.initials: S
authors.lastname: Hennequin
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ebihara
authors.forename: Motomi
authors.initials: M
authors.lastname: Ito
authors.forename: Kunio
authors.initials: K
authors.lastname: Iwatsuki
authors.forename: Jean Yves
authors.initials: JY
authors.lastname: Dubuisson
mesh_terms: D017931:DNA Primers / Q000235:genetics; D018742:DNA, Chloroplast / Q000235:genetics*; D019143:Evolution, Molecular; D029624:Ferns / Q000145:classification* / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics; D017354:Point Mutation / Q000235:genetics; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics
chemical_list: D017931:DNA Primers; D018742:DNA, Chloroplast; D010940:Plant Proteins; C097421:rps4 protein, plant; C101625:RbcL protein, plastid; D012273:Ribulose-Bisphosphate Carboxylase