Three molecular markers suggest different relationships among three Drepanocladus species (Bryophyta: Amblystegiaceae)

Abstract

Relationships among numerous specimens of Drepanocladus angustifolius (35 specimens), Drepanocladus lycopodioides (71 specimens), and Drepanocladus turgescens (102 specimens) are analysed based on the nuclear internal transcribed spacers 1 and 2 (ITS) and a portion of glyceraldehyde 3-phosphate dehydrogenase (gpd), and the plastid rpl16 G2 intron. Molecular data suggest that neither species is monophyletic as well as significant incongruence among molecular markers. No statistical support for recombination (ITS, gpd) was found. For some D. lycopodioides and D. turgescens specimens, the molecular information even suggests that they belong to the wrong one of these two species. All such specimens were collected in south Swedish areas where the two species are frequently found growing together and where sporophytes are often common. The occurrence of all such specimens only in these geographical areas is statistically unlikely and suggests that hybridisation occasionally occurs here. While molecular information suggests that the species are not monophyletic, geographical signals could be found for both D. angustifolius and D. turgescens.