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In plants, hybridization between interspecific taxa leading to chromosome doubling seems to happen regularly and may be an important driver of speciation. Allopolyploid species often have morphological traits from both parents, broader ecological niches, and are hypothesized to be more common going northwards. About 20% of all Sphagnum species have been inferred to be allopolyploids. Here we describe the first allotriploid Sphagnum species in the northern hemisphere, using molecular data, Feulgen densitometry, and morphological examination. Our molecular data also supports the finding of the first polyploid species with inter-subgeneric origin between Acutifolia and Subsecunda. Morphological examination further supports this finding. The Acutifolia progenitor is likely the maternal parent of the new species, named S. ×lydiae, and it is probably S. incundum, S. ×arcticum or S. ×olafii. The Subsecunda parent could not be identified based on molecular and morphological characters. The currently known distribution of S. ×lydiae is confined to regions with arctic and subarctic climate and tundra vegetation in northern Russia.

Biodiversity of threatened species can be preserved in cryopreservation repositories, allowing storage of biological information and future re-introduction to the wild. The success of ex situ programs for species conservation relies on using simple and efficient cryopreservation techniques. Bryophytes may be classified as stress-tolerant plants, but a large fraction worldwide is nevertheless threatened by extinction to various degrees. The aims of this study were to investigate how to exploit natural stress tolerance of bryophytes in the development of simple cryopreservation protocols without the use of cryoprotectants or pretreatment. We studied regeneration capacity of bryophytes found at different moisture and light conditions in vivo (reflecting varying levels of plant desiccation tolerance), both sampled from herbarium specimens of varying ages and also collected in situ during winter season and thus naturally cold acclimated. Furthermore, to identify optimal samples for direct cryopreserva...

Bryophytes are an important plant group with long-term dominance in alpine habitats. The alpine environment is however severe, and may restrict variation in bryophyte life history. This study examines the relationship between frequencies of bryophyte species and their life history traits between and within two alpine environments that differ in important environmental variables identified for bryophytes: 1) an oceanic region, with humid acidic soils (Setesdal) and 2) a sub-continental region, with more dry, productive, base-rich soils (Hol). A comparison between regions showed a higher frequency of base-demanding bryophytes in the sub-continental region. Sexual reproduction was more common among bryophytes in the oceanic region and these species also had higher indicator values for oceanic conditions and temperature as expected. Several life history traits were strongly correlated with bryophyte frequencies in the oceanic region—local species abundance increased in relation to shoot longevity, di...

Genetic structure and diversity were studied in the endangered peatmoss Sphagnum angermanicum Melin to assess its conservation status. In total, 128 shoots from eleven populations throughout its Swedish distribution were analyzed. Among these shoots 28 haplotypes were identified by 19 ISSR loci. The most common haplotype (50% of the sampled shoots) occurred in all populations. The level of gene diversity over loci was intermediate compared to records from most other bryophytes. There was no genetic isolation between the populations and most of the genetic variation was found within populations. This implies either that the populations have originated from only a few common individuals or a high gene flow between populations. A relict population model is suggested to explain the observed pattern. Just after the last glaciation, S. angermanicum may have expanded its range when suitable habitat became available after the glacial ice retreated. Since then, habitats have vanished or fragmented and tod...

Many islands are characterized by high biological diversity, and both adaptive and non-adaptive factors have been found to contribute to island richness. Here we study extensive color morph variability in the allopolyploid peat moss Sphagnum palustre on the Azores Islands. By comparing genetic diversity patterns in island and mainland populations we evaluate various hypotheses for the high diversity observed within and between islands. We conclude that the diversity observed cannot be explained by Azores Islands having acted as refugia for morphotypes during Pleistocene glacial periods. Furthermore, high island diversity is not the result of past or ongoing adaptive radiations. Lack of genetic differentiation and free reproduction among morphs growing closely together is not consistent with adaptive differentiation in space or time to changing environmental conditions. We conclude that high island diversity in this species likely reflects phenotypic plasticity, possibly in response to unfavourabl...