Evolution of the Neckeraceae (Bryophyta): Resolving the backbone phylogeny

Abstract

Earlier phylogenetic studies, including species belonging to the Neckeraceae, have indicated that this pleurocarpous moss family shares a strongly supported sister group relationship with the Lembophyllaceae, but the family delimitation of the former needs adjustment. To test the monophyly of the Neckeraceae, as well as to redefine the family circumscription and to pinpoint its phylogenetic position in a larger context, a phylogenetic study based on molecular data was carried out. Sequence data were compiled, combining data from all three genomes: nuclear ITS1 and 2, plastid trnS-rps4-trnT-trnL-trnF and rpl16, and mitochondrial nad5 intron. The Neckeraceae have sometimes been divided into the two families, Neckeraceae and Thamnobryaceae, a division rejected here. Both parsimony and Bayesian analyses of molecular data revealed that the family concept of the Neckeraceae needs several further adjustments, such as the exclusion of some individual species and smaller genera as well as the inclusion of the Leptodontaceae. Within the family three wellsupported clades (A, B and C) can be distinguished. Members of clade A are mainly non-Asiatic and nontropical. Most species have a weak costa and immersed capsules with reduced peristomes (mainly Neckera spp.) and the teeth at the leaf margins are usually unicellular. Clade B members are also mainly non-Asiatic. They are typically fairly robust, distinctly stipitate, having a single, at least relatively strong costa, long setae (capsules exserted), and the peristomes are well developed or only somewhat reduced. Members of clade C are essentially Asiatic and tropical. The species of this clade usually have a strong costa and a long seta, the seta often being mammillose in its upper part. The peristome types in this clade are mixed, since both reduced and unreduced types are found. Several neckeraceous genera that were recognised on a morphological basis are polyphyletic (e.g. Neckera, Homalia, Thamnobryum, Porotrichum). Ancestral state reconstructions revealed that currently used diagnostic traits, such as the leaf asymmetry and costa strength are highly homoplastic. Similarly, the reconstructions revealed that the 'reduced' sporophyte features have evolved independently in each of the three clades.

20,000 species and five key markers: The status of molecular bryophyte phylogenetics

“…100 nt from the intron/exon junction. However, due to amplification and sequencing problems Olsson et al (2009b) proposed to substitute R1661 with a new primer rpl16R to yield better amplification and sequencing results. Future studies might want to position the forward primer inside rps3 instead of using F71, as the latter does not provide the full G2 intron length (see Tesfaye et al 2007) and thus limits molecular evolutionary studies.…”

Phylogenetic relationships in the ‘Pinnatella’ clade of the moss family Neckeraceae (Bryophyta)

“…According to the latest studies, the pleurocarpous mosses as defined by Bell et al (2007) form a monophylum ("core pleurocarps") that can be divided in four orders: Hypnodendrales, Ptychomniales, Hookeriales and Hypnales, the latter including the Neckeraceae. This family contains mainly temperate and tropical species; the species number is estimated at around 200 (Enroth 1994a;Olsson et al 2009a). The species are mostly epiphytic or epilithic, but there are also some aquatic (rheophytic) ones.…”

“…The species are mostly epiphytic or epilithic, but there are also some aquatic (rheophytic) ones. A morphological characterization of the Neckeraceae is provided by Olsson et al (2009a). Olsson et al (2009b) resolved the backbone relationships of the Neckeraceae, its sister-group relation to the Lembophyllaceae, and revealed that the Neckeraceae can be divided in three distinct clades.…”

“…The three resolved clades were named: Neckera clade, Thamnobryum clade and 'Pinnatella' clade, the first two after the respective most species-rich genus included. In addition, morphological definitions of, and evolutionary trends in, the clades were discussed (Olsson et al 2009a).…”

<p><strong><em>Neckera xizangensis</em> (Neckeraceae, Bryophyta), a new species from China</strong></p>

“…5 0 species world-wide (Enroth 1994). That number is probably much too high since Neckera in its traditional and current circumscription is known to be polyphyletic (Olsson et al 2009). However, since the specific and generic phylogenies are not yet adequately studied or the necessary taxonomic changes made, we follow the old generic concept here.…”