Intraspecific genetic variation in selected mosses of Scandinavian interglacial refugia suggests contrasting distribution history patterns

Abstract

Three pleurocarpous mosses were studied to explore the haplotype diversity patterns in a Scandinavian system of interglacial refugia in which low-competitive species of calcareous or base-rich habitats occur. Hypnum bambergeri and H. vaucheri displayed little variation across Scandinavia. For the third species, Drepanocladus turgescens, an analysis of molecular variance showed that two S Scandinavian lowland regional populations were significantly different from each other and differed or almost differed (Gotland vs. Jämtland, according to pair-wise ΦPT) from the populations of the Scandinavian mountain range and Svalbard. Haplotype diversity displayed little variation among regional populations, and did not reflect the higher frequency of sexual reproduction in southern than in mountain populations. A coalescent-based analysis (LAMARC) indicated immigration into the population now found in the lowlands from that represented in the mountains. This is contrary to that found in Rhytidium rugosum in an earlier study and, together with the fact that sporophytes are produced almost exclusively in the lowlands, speaks against this direction of post-glacial migration. Therefore, if the LAMARC results reflect migration patterns, these most probably reflect events that occurred earlier. Taken together with the results on R. rugosum, this study emphasizes the fact that moss species having similar distribution patterns reached these distributions in partly different ways.

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

“…The molecular methods used here for D. angustifolius were described earlier (Hedenäs 2014;Hedenäs and Bisang 2015), and the reader is referred to these works for further details. For the internal transcribed spacers 1 and 2 (ITS), the primers'18SF' and '26SR' (Rydin et al 2004) or 'ITS4-bryo' (Stech 1999) and 'ITSbryoR' (Hedenäs 2014) were used.…”

“…For the internal transcribed spacers 1 and 2 (ITS), the primers'18SF' and '26SR' (Rydin et al 2004) or 'ITS4-bryo' (Stech 1999) and 'ITSbryoR' (Hedenäs 2014) were used. For a portion of glyceraldehyde 3-phosphate dehydrogenase (gpd), the primers '1790F' (Wall 2002), 'GPD68F', 'GPD-460F' (Hedenäs and Bisang 2015), 'GPD3050Rr' (Hedenäs 2014), and 'GPD-bryonestedR' (Hedenäs and Bisang 2013) were employed, and for the rpl16 G2 intron (rpl16), the primers 'F71' (Jordan et al 1996) and 'rpl16-antR2' (Hedenäs 2008) were used.…”

“…Sequences of 35 specimens of D. angustifolius were newly generated, whereas 71 of D. lycopodioides and 102 of D. turgescens were available from earlier phylogeographic studies (Hedenäs 2014;Hedenäs and Bisang 2015). Because northern Europe was the focus of the earlier studies, this area is well covered, but other portions of Europe or (D. angustifolius, D. turgescens) outside Europe are also represented.…”

“…Based on the results of Hedenäs and Rosborg (2009), two specimens of D. aduncus were used as outgroup in the analysis. The specimens of D. angustifolius are listed in Table 1, whereas those of the other species are listed in Hedenäs (2014) and Hedenäs and Bisang (2015).…”

“…2). Here, this D. lycopodioides sequence data set is combined with that of D. turgescens from Hedenäs (2014) and newly generated sequences of the closely related Drepanocladus angustifolius (Hedenäs) (Hedenäs and Rosborg 2009). Together, this provides an excellent data set to study potential incongruence among data sets and to search for evidence of potential hybridisation in a group of pleurocarpous mosses that is not closely related to the earlier studied Calliergonaceae (cf., Huttunen et al 2012).…”