Species delimitations in theDicranum acutifoliumcomplex (Dicranaceae, Bryophyta) using molecular markers

Abstract

Because of their morphological plasticity and broad geographic distribution, the taxonomy of Dicranum is difficult. The circumscription of the different species included in the Dicranum acutifolium complex is poorly understood and taxonomic confusions are frequent. The present study extends earlier internal transcribed spacer (ITS)-based phylogenetic reconstructions of the D. acutifolium complex by analysing five additional chloroplast markers (trnTrps4, trnL-F, psbA-trnH, rps19-rpl2, rpoB) together with ITS from a larger taxon sample. The phylogenetic analyses delimit Dicranum acutifolium (Lindb. & Arnell) C.E.O.Jensen, D. bardunovii Tubanova & Ignatova, D. brevifolium (Lindb.) Lindb., and D. septentrionale Tubanova & Ignatova, which together form the D. acutifolium complex, and confirm that D. pseudoacutifolium Otnyukova is synonymous with D. flexicaule Brid. Previously Dicranum septentrionale was known from across Russia, but it also occurs in Scandinavia, where it was probably overlooked due to the morphological resemblance to D. brevifolium. The problem of mixed collections for identification is exemplified by the holotype of D. bardunovii, which also contains individuals of the morphologically most similar D. acutifolium, according to the molecular data. Morphometric analyses support the differentiation of the D. acutifolium complex. Furthermore, ordination analyses point to a continuous range of variation among species within the D. acutifolium complex, especially due to the larger variation in D. septentrionale.

Phylogeny and species delimitations in European Dicranum (Dicranaceae, Bryophyta) inferred from nuclear and plastid DNA

“…also Stech and Quandt, 2010 in several species (e.g. Lang et al, 2014b;Tubanova et al, 2010). (Lang et al, 2014a,b), which is supported in the present study, in 403 particular by GMYC (Fig.…”

“…Thus, assessing species delimitations in Dicranum is chal-114 lenging both at the morphological and molecular level. Our recent 115 studies on the Dicranum scoparium and D. acutifolium species com-116 plexes (Lang and Stech, 2014;Lang et al, 2014b) as well as on 117 boreal-arctic Dicranum species (Lang et al, 2014a) showed that 118 in several cases conclusive species delimitations could only be 119 obtained from combined analyses of several chloroplast markers 120 and nuclear ribosomal ITS sequences. 121 The present study aims to elucidate species boundaries within 122 Dicranum on a broad geographic scale, including 27 of the 29 123 Dicranum species occurring in Europe (Hedenäs and Bisang,124 2004) plus D. septentrionale Tubanova and Ignatova, a newly 125 recorded species in Scandinavia (Lang et al, 2014b).…”

“…Our recent 115 studies on the Dicranum scoparium and D. acutifolium species com-116 plexes (Lang and Stech, 2014;Lang et al, 2014b) as well as on 117 boreal-arctic Dicranum species (Lang et al, 2014a) showed that 118 in several cases conclusive species delimitations could only be 119 obtained from combined analyses of several chloroplast markers 120 and nuclear ribosomal ITS sequences. 121 The present study aims to elucidate species boundaries within 122 Dicranum on a broad geographic scale, including 27 of the 29 123 Dicranum species occurring in Europe (Hedenäs and Bisang,124 2004) plus D. septentrionale Tubanova and Ignatova, a newly 125 recorded species in Scandinavia (Lang et al, 2014b). Molecular 126 phylogenetic reconstructions based on five chloroplast markers 127 (trnH GUG -psbA, rps4-trnT UGU and trnL UAA -trnF GAA intergenic spac-128 ers, rps19-rpl2, rpoB) plus the nrITS1-5.8S-ITS2 region will be used 129 to test, to our knowledge for the first time in bryophytes, the con- Tubanova et al (2010), Ignatova and Fedosov (2008).…”

“…septentrionale, recently described from Russia and newly identified 373 in Scandinavia(Tubanova et al, 2010;Lang et al, 2014b). The 374 majority of the analyzed species (19 out of 27), were molecularly 375 recognisable based on the combined analysis of five chloroplast 376 markers and nuclear ribosomal ITS sequences(Fig.…”

“…Molecular 126 phylogenetic reconstructions based on five chloroplast markers 127 (trnH GUG -psbA, rps4-trnT UGU and trnL UAA -trnF GAA intergenic spac-128 ers, rps19-rpl2, rpoB) plus the nrITS1-5.8S-ITS2 region will be used 129 to test, to our knowledge for the first time in bryophytes, the con- Tubanova et al (2010), Ignatova and Fedosov (2008). The other 155 162 specimens were sequenced for previous studies (Lang and 156 Stech, 2014;Lang et al, 2014aLang et al, , 2014bStech, 1999;Stech et al, 157 2006). We chose as outgroup four specimens of Holomitrium, sister 158 genus of the Dicranum s.l.…”