Norwegian version of this page

Anne Krag Brysting

Professor - Centre for Ecological and Evolutionary Synthesis

Email a.k.brysting@ibv.uio.no

Phone +47 22 85 75 77

Room 3227

Username

Visiting address Blindernveien 31 0371 Oslo

Postal address Postboks 1066 Blindern 0316 Oslo

Download business card

Background

The overall coherence in my research activities is a strong-willed wish to contribute to a deeper understanding of plant evolution and speciation.

From the start, one focus has been polyploid evolution. As polyploid plants are found at high numbers in arctic and alpine regions, this fitted well with a general focus on phylogeny and phylogeography of the arctic-alpine flora. Polyploidization has probably occurred repeatedly through the entire Quaternary. Successive hybridization and polyploidization events have build up high-polyploid species complexes of allopolyploids with network-like histories.

Important in the speciation process is the establishment of reproductive barriers. In the NFR funded MOLBAR project (The molecular basis of postzygotic hybridization barriers in plants), we study postzygotic barriers that prevent the embryo from developing normally when germ cells from two different species merge. The embryo develops inside the seed, and in most plants the seed contains in addition nutritive tissue (endosperm) that the new plant needs to grow big. We specifically study the embryo and endosperm development in seeds resulting from crosses between different Brassicaceae species.

Species are the most fundamental unit in nature, and yet we know little about how long it takes for new species to arise and what factors influence the rate of speciation. In the SpeciationClock project (How fast does the "speciation clock" tick in selfing versus outcrossing lineages?), we address the fundamental question of how fast new species arise, and specifically test if the plant ‘speciation clock’ ticks faster in self-fertilizing than outcrossing lineages. Our main objective is to develop and empirically test theoretical models of the impact of mating systems on the genetic architecture and rate of speciation, i.e. the ticking of the ‘speciation clock(s)’.

Scientific pledge

I have read and promise to adhere to the NENT.

Tags: Botany, Phylogeography, Phylogenetics, Plant systematics, Plants, Polyploidy, Speciation

Mjøen, Hedvig Elisabeth; Løken, Solveig Bua; Carlsen, Tor; Brysting, Anne Krag & Bjorå, Charlotte Sletten (2026). Resolving the Veratrum phylogeny in northern Fennoscandia by targeted sequencing. Taxon. ISSN 0040-0262. 75(4). doi: 10.1002/tax.70201. Full text in Research Archive Show summary
The genus Veratrum comprises approximately 24 species from temperate and arctic North America and Eurasia. In Europe, Veratrum is mainly distributed in mountainous areas of central and southern Europe but is also locally abundant in coastal areas of north-eastern Finnmark, Norway. The taxon name for the Veratrum in Finnmark has over the years been disputed. Several names have been applied, including V. album, V. lobelianum, and various subspecies of these. Previous phylogenetic analyses of Veratrum based on Sanger sequences of the ITS region have lacked sufficient resolution to resolve the relationships within the genus. Furthermore, the Veratrum in Finnmark has not been included in any molecular phylogenetic analysis, leaving its relationship to other populations of Veratrum unknown. The aims of this study were therefore to place the Veratrum in Finnmark in a molecular phylogenetic context, assess if this group represents a separate taxon, and determine the appropriate nomenclature. We applied a target capture approach, using the Angiosperms-353 probe set, to obtain a multi-locus phylogenetic dataset. Our phylogeny reveals that the Veratrum in Finnmark are closely related to Veratrum populations in northern Finland and Russia. Northern European Veratrum resolves as a distinct clade and represents a distinct taxon separate from populations in central Europe. We propose the name V. album subsp. misae for the northern European Veratrum.
Tjessem, Ingrid Vesterdal; Brysting, Anne Krag; Reitan, Trond; Hjelle, Simen Salomonsen & Eidesen, Pernille Bronken (2026). A shift in species niche through autopolyploidy: From sexual to vegetative reproduction in Saxifraga oppositifolia. Annals of Botany. ISSN 0305-7364. doi: 10.1093/aob/mcag116. Full text in Research Archive Show summary
Background and Aims Polyploidy has been essential in the evolution of angiosperms, facilitating novel adaptations, enhancing speciation and contributing to the establishment of larger evolutionary lineages. However, newly formed polyploids require sufficient niche differentiation to survive and coexist with the diploid ancestor. Polyploids are commonly reproductively challenged, which may lead to rapid development of asexual reproduction, which may, in turn, lead to reproductive barriers or ecological niche divergence. Through this study, we investigate whether autopolyploidization has induced a shift from sexual reproduction to vegetative propagation in the arctic–alpine Saxifraga oppositifolia (Saxifragaceae) and thus facilitated the establishment of polyploids in mixed-cytotype populations. Methods We sampled data on capsule and seed production, seed germination, rooting ability, and leaf production among cytotypes through a combination of growth chamber experiments and in situ observations in a field set-up across different habitats (ridges, slopes, riverbeds) in Svalbard including >700 georeferenced S. oppositifolia plants with known cytotype (diploid, triploid or tetraploid). Through hypothesis testing and an explorative model search for relevant covariates (e.g. growth form, habitat, soil type), we tested the effect of cytotype on sexual and vegetative reproductive outcomes. Key Results Polyploids had lower sexual reproductive investment (i.e. capsule production and seed production) and higher vegetative investment (i.e. leaf production and rooting ability), showing that polyploidy has significantly affected both sexual reproduction and vegetative propagation. Conclusions Our findings confirm a shift in reproductive strategy towards less sexual investment and enhanced vegetative investment in triploid and tetraploid individuals. This shift may enhance polyploid survival in habitats with shorter growing season and limited pollinator availability, and thus explains their higher frequency in such habitats. These results support autopolyploidy as an evolutionary mechanism that may allow Arctic species to adapt to ongoing, rapid changes.
Asplund, Ulrika Jansson; Karlsen, Damian Petkovic; Brysting, Anne Krag; Halvorsen, Rune; Kauserud, Håvard & Kjønaas, Janne [Show all 7 contributors for this article] (2026). Long-term effects of clear-cutting on understory plant communities in boreal forests. Forest Ecology and Management. ISSN 0378-1127. 613. doi: 10.1016/j.foreco.2026.123784. Full text in Research Archive Show summary
After five centuries of selective cutting in the boreal Fennoscandian forest there was a shift to stand replacing harvest (clear-cutting) in the 1940s. This shift altered light conditions experienced by the forest understory profoundly, from semi-open conditions to light regimes altering between very open in the recently clear-cut forest to very dense some decades later. In this study, we investigated the long-term effects of clear-cutting on vascular plants and bryophytes. Our study system consists of twelve pairs of mesic spruce forests in Southeastern Norway, with a previously clear-cut, but now mature stand and a near-natural forest within each pair. Vascular plant cover was almost twice as high in the near-natural than in the mature, previously clear-cut forest sites, despite similar standing volume and light availability. Overall, previous clear-cutting did not have long-term effects on species richness, but vascular plant species richness was more responsive to soil Ca, a key driver of plant community composition, in the near natural forests. Likewise, the community composition showed a stronger association with soil chemistry in near-natural forests, suggesting that management alters natural drivers of understory communities. The long-lasting effects of clear-cutting was distinct for understory cover and mainly driven by common species such as the keystone species Vaccinium myrtillus, which was substantially less abundant in previously clear-cut stands.
Eidesen, Pernille Bronken; Elven, Reidar; Arnesen, Geir; Alsos, Inger Greve; Brysting, Anne Krag & Christensen, Maj Sofie [Show all 7 contributors for this article] (2025). Lavarktiske planter i en høyarktisk oase – tre nye arter for Svalbard registrert i Indre Wijdefjord nasjonalpark. Blyttia : Norsk botanisk forenings tidsskrift. ISSN 0006-5269. 83(3), p. 169–175. doi: https:/nhm2.uio.no/botanisk/nbf/blyttia/blyttia_pdf/Blyttia%20202503_OMSLAG%2020250910_01%20SCREEN%204.pdf. Full text in Research Archive Show summary
Indre Wijdefjorden National Park in Northern Spitsbergen is housing several regionally rare vascular plant species. In later years we have found three plant species new to Svalbard in the rich and thermic favourable scree slopes in the Ringhorndalen – Flatøyrdalen valleys: Erigeron uniflorus, Festuca ovina, and Luzula spicata. In all three cases, these sites are by far the northernmost registered locations for these species in the world, separated from their nearest known sites to the south by 800–1000 km or more. The highly isolated occurrence of these three species, and several others with similar gaps to their nearest sites in the south, most likely represent remnants from larger populations thriving during the Holocene climatic optimum.
Eidesen, Pernille Bronken; Brysting, Anne Krag; Hagen, Kathleen Rani; Hjelle, Simen Salomonsen; Revéret, Aloïs Nicolas & Tjessem, Ingrid Vesterdal [Show all 26 contributors for this article] (2025). Ecological and evolutionary consequences of ploidy-driven trait variation: insights from Saxifraga oppositifolia L. Arctic Science. ISSN 2368-7460. 11, p. 1–26. doi: 10.1139/as-2024-0020. Full text in Research Archive Show summary
The ecological and evolutionary consequences of ploidy-driven trait variation, particularly for autopolyploids, remain poorly understood. Saxifraga oppositifolia L. (purple saxifrage), is a highly successful arctic-alpine plant species with significant genetic and phenotypic variation potentially related to autopolyploidy. Over the past decade, we have accumulated knowledge of S. oppositifolia through student projects at the University Centre in Svalbard. Building on this knowledge, we initiated the long-term “SO-field study” in 2018 including 768 permanently tagged plants screened for ploidy level, trait variation and environmental associations. Here we summarize main findings from unpublished student projects, consolidating and extending these findings with the available data from the ongoing SO-field study, containing 63% diploids, 16% triploids, and 21% tetraploids. Our results support that Svalbard is a mixed-ploidy contact zone, where ploidy is strongly associated with certain traits, including growth form, leaf mass area, flower investment, seed production and habitat. Autopolyploidy has significantly influenced both ecology and evolution of S. oppositifolia and needs to be accounted for when autopolyploids are used as a study species or evaluated for management purposes. Our findings suggest considerable re-interpretation of former research and pave the way for new inquiries and hypotheses to be tested within this framework.
Marie-Orleach, Lucas; Glémin, Sylvain; Brandrud, Marie Kristine; Brysting, Anne Krag; Seid, Abel Gizaw & Gustafsson, A Lovisa S [Show all 9 contributors for this article] (2024). How Does Selfing Affect the Pace and Process of Speciation? Cold Spring Harbor Perspectives in Biology. 16(11). doi: 10.1101/cshperspect.a041426. Full text in Research Archive Show summary
Surprisingly little attention has been given to the impact of selfing on speciation, even though selfing reduces gene flow between populations and affects other key population genetics parameters. Here we review recent theoretical work and compile empirical data from crossing experiments and genomic and phylogenetic studies to assess the effect of mating systems on the speciation process. In accordance with theoretical predictions, we find that accumulation of hybrid incompatibilities seems to be accelerated in selfers, but there is so far limited empirical support for a predicted bias toward underdominant loci. Phylogenetic evidence is scarce and contradictory, including studies suggesting that selfing either promotes or hampers speciation rate. Further studies are therefore required, which in addition to measures of reproductive barrier strength and selfing rate should routinely include estimates of demographic history and genetic divergence as a proxy for divergence time.
Bramsiepe, Jonathan; Krabberød, Anders Kristian; Bjerkan, Katrine Nergård; Alling, Renate; Nielsen, Ida & Hornslien, Karina Stensland [Show all 9 contributors for this article] (2023). Structural evidence for MADS-box type I family expansion seen in new assemblies of Arabidopsis arenosa and A. lyrata. The Plant Journal. ISSN 0960-7412. 116(3), p. 942–961. doi: 10.1111/tpj.16401. Full text in Research Archive Show summary
SUMMARY Arabidopsis thaliana diverged from A. arenosa and A. lyrata at least 6 million years ago. The three species differ by genome‐wide polymorphisms and morphological traits. The species are to a high degree reproductively isolated, but hybridization barriers are incomplete. A special type of hybridization barrier is based on the triploid endosperm of the seed, where embryo lethality is caused by endosperm failure to support the developing embryo. The MADS‐box type I family of transcription factors is specifically expressed in the endosperm and has been proposed to play a role in endosperm‐based hybridization barriers. The gene family is well known for its high evolutionary duplication rate, as well as being regulated by genomic imprinting. Here we address MADS‐box type I gene family evolution and the role of type I genes in the context of hybridization. Using two de‐novo assembled and annotated chromosome‐level genomes of A. arenosa and A. lyrata ssp. petraea we analyzed the MADS‐box type I gene family in Arabidopsis to predict orthologs, copy number, and structural genomic variation related to the type I loci. Our findings were compared to gene expression profiles sampled before and after the transition to endosperm cellularization in order to investigate the involvement of MADS‐box type I loci in endosperm‐based hybridization barriers. We observed substantial differences in type‐I expression in the endosperm of A. arenosa and A. lyrata ssp. petraea , suggesting a genetic cause for the endosperm‐based hybridization barrier between A. arenosa and A. lyrata ssp. petraea .
Bjerkan, Katrine Nergård; Alling, Renate; Myking, Ida Velle; Brysting, Anne Krag & Grini, Paul (2023). Genetic and environmental manipulation of Arabidopsis hybridization barriers uncovers antagonistic functions in endosperm cellularization. Frontiers in Plant Science. 14, p. 1–16. doi: 10.3389/fpls.2023.1229060. Full text in Research Archive Show summary
Speciation involves reproductive isolation, which can occur by hybridization barriers acting in the endosperm of the developing seed. The nuclear endosperm is a nutrient sink, accumulating sugars from surrounding tissues, and undergoes coordinated cellularization, switching to serve as a nutrient source for the developing embryo. Tight regulation of cellularization is therefore vital for seed and embryonic development. Here we show that hybrid seeds from crosses between Arabidopsis thaliana as maternal contributor and A. arenosa or A. lyrata as pollen donors result in an endosperm based post-zygotic hybridization barrier that gives rise to a reduced seed germination rate. Hybrid seeds display opposite endosperm cellularization phenotypes, with late cellularization in crosses with A. arenosa and early cellularization in crosses with A. lyrata . Stage specific endosperm reporters display temporally ectopic expression in developing hybrid endosperm, in accordance with the early and late cellularization phenotypes, confirming a disturbance of the source-sink endosperm phase change. We demonstrate that the hybrid barrier is under the influence of abiotic factors, and show that a temperature gradient leads to diametrically opposed cellularization phenotype responses in hybrid endosperm with A. arenosa or A. lyrata as pollen donors. Furthermore, different A. thaliana accession genotypes also enhance or diminish seed viability in the two hybrid cross-types, emphasizing that both genetic and environmental cues control the hybridization barrier. We have identified an A. thaliana MADS-BOX type I family single locus that is required for diametrically opposed cellularization phenotype responses in hybrid endosperm. Loss of AGAMOUS-LIKE 35 significantly affects the germination rate of hybrid seeds in opposite directions when transmitted through the A. thaliana endosperm, and is suggested to be a locus that promotes cellularization as part of an endosperm based mechanism involved in post-zygotic hybrid barriers. The role of temperature in hybrid speciation and the identification of distinct loci in control of hybrid failure have great potential to aid the introduction of advantageous traits in breeding research and to support models to predict hybrid admixture in a changing global climate.
Olsen, Luka Natassja; Brandrud, Marie Kristine; Mandáková, Terezie; Lysak, Martin A; Bjorå, Charlotte Sletten & Cires, Eduardo [Show all 8 contributors for this article] (2022). Genetic structure and evolution of diploid Cochlearia in Iceland. Botanical journal of the Linnean Society. ISSN 0024-4074. 200(3), p. 395–415. doi: 10.1093/botlinnean/boac018. Full text in Research Archive Show summary
Abstract In northern European Cochlearia (Brassicaceae), considerable chromosome variation has taken place without corresponding morphological differentiation, resulting in an intricate species complex including two base chromosome numbers and several ploidies. Here, we investigate the situation in Iceland. The distribution, genetic structure, taxonomy and origin of the two Cochlearia cytotypes (2n = 12 and 2n = 14) present in Iceland are discussed. Chromosome counts indicate that both cytotypes occur along the coast, but 2n = 12 populations dominate (eight 2n = 12 vs. two 2n = 14 among the investigated populations), whereas 2n = 14 was reported for the two inland alpine populations investigated here. RADseq data support geographically structured genetic variation along the Icelandic coast and environmentally structured genetic differentiation between coastal and alpine populations. The alpine populations show genetic and morphological affiliation with C. groenlandica (2n = 14), which is widely distributed in the Arctic, but more comprehensive sampling is needed to draw conclusions concerning the taxonomic status of the Icelandic coastal plants. To uncover the origin of and phylogenomic relationships between the two chromosome variants, comparative whole-genome sequencing should be performed.
Schure, Anneke ter; Bruch, Angela A.; Kandel, Andrew W.; Gasparyan, Boris; Bussmann, Rainer W. & Brysting, Anne Krag [Show all 8 contributors for this article] (2022). Sedimentary ancient DNA metabarcoding as a tool for assessing prehistoric plant use at the Upper Paleolithic cave site Aghitu-3, Armenia. Journal of Human Evolution. ISSN 0047-2484. 172. doi: 10.1016/j.jhevol.2022.103258. Full text in Research Archive Show summary
Current knowledge about Paleolithic human plant use is limited by the rare survival of identifiable plant remains as well as the availability of methods for plant detection and identification. By analyzing DNA preserved in cave sediments, we can identify organisms in the absence of any visible remains, opening up new ways to study details of past human behavior, including plant use. Aghitu-3 Cave contains a 15,000-yearlong record (from ∼39,000 to 24,000 cal BP) of Upper Paleolithic human settlement and environmental variability in the Armenian Highlands. Finds from this cave include stone artifacts, faunal remains, bone tools, shell beads, charcoal, and pollen, among others. We applied sedimentary ancient DNA (sedaDNA) metabarcoding to the Aghitu-3 sedimentary sequence and combined this with pollen data to obtain a temporal reconstruction of plant assemblages. Our results reveal a stratification of plant abundance and diversity where sedaDNA reflects periods of human occupation, showing higher diversity in layers with increased human activity. Low pollen concentrations combined with high sedaDNA abundance indicate plant remains may have been brought into the cave by animals or humans during the deposition of the lower two archaeological horizons. Most of the recovered plants are reported to be useful for food, flavor, medicine, and/or technical purposes, demonstrating the potential of the environment around Aghitu-3 Cave to support humans during the Upper Paleolithic. Moreover, we identified several specific plant taxa that strengthen previous findings about Upper Paleolithic plant use in this region (i.e., for medicine and the manufacturing and dyeing of textiles). This study represents the first application of plant sedaDNA analysis of cave sediments for the investigation of potential plant use by prehistoric humans.
Birkeland, Siri; Slotte, Tanja; Brysting, Anne Krag; Gustafsson, Lovisa; Hvidsten, Torgeir Rhoden & Brochmann, Christian [Show all 7 contributors for this article] (2022). What can cold-induced transcriptomes of Arctic Brassicaceae tell us about the evolution of cold tolerance? Molecular Ecology. ISSN 0962-1083. 31(16), p. 4271–4285. doi: 10.1111/mec.16581. Full text in Research Archive Show summary
Little is known about the evolution of cold tolerance in polar plant species and how they differ from temperate relatives. To gain insight into their biology and the evolution of cold tolerance, we compared the molecular basis of cold response in three Arctic Brassicaceae species. We conducted a comparative time series experiment to examine transcriptional responses to low temperature. RNA was sampled at 22°C, and after 3, 6, and 24 at 2°C. We then identified sets of genes that were differentially expressed in response to cold and compared them between species, as well as to published data from the temperate Arabidopsis thaliana. Most differentially expressed genes were species-specific, but a significant portion of the cold response was also shared among species. Among thousands of differentially expressed genes, ~200 were shared among the three Arctic species and A. thaliana, while ~100 were exclusively shared among the three Arctic species. Our results show that cold response differs markedly between Arctic Brassicaceae species, but probably builds on a conserved basis found across the family. They also confirm that highly polygenic traits such as cold tolerance may show little repeatability in their patterns of adaptation.
Schure, Anneke Theresia Maria ter; Bajard, Manon Juliette Andree; Loftsgarden, Kjetil; Høeg, Helge Irgens; Ballo, Eirik Gottschalk & Bakke, Jostein [Show all 12 contributors for this article] (2021). Anthropogenic and environmental drivers of vegetation change in southeastern Norway during the Holocene. Quaternary Science Reviews. ISSN 0277-3791. 270. doi: 10.1016/j.quascirev.2021.107175. Full text in Research Archive Show summary
Uncovering anthropogenic and environmental drivers behind past biological change requires integrated analyses of long-term records from a diversity of disciplines. We applied an interdisciplinary approach exploring effects of human land-use and environmental changes on vegetation dynamics at Lake Ljøgottjern in southeastern Norway during the Holocene. Combined analysis of pollen and sedimentary ancient DNA (sedaDNA) metabarcoding of the sedimentary sequence of the lake describes the vegetation dynamics at different scales, and establishes a timeline for pastoral farming activities. We integrate this reconstruction with geochemical analysis of the sediments, climate data, archaeological evidence of local human settlement and regional human population dynamics. Our data covering the last 10,000 years reveals consistent vegetation signals from pollen and sedaDNA indicating periods of deforestation connected to cultivation, matching the archaeological evidence. Multivariate analysis integrating the environmental data from geochemical and archaeological reconstructions with the vegetation composition indicates that the vegetation dynamics at Lake Ljøgottjern were primarily related to natural processes from the base of the core (in ca. 8000 BCE, Mesolithic) up to the Early Iron Age (ca. 500 BCE–550 CE), when agricultural activities in the region intensified. The pollen signal reflects the establishment of a Bronze Age (ca. 1800–500 BCE) farm in the area, while subsequent intensification of pollen concentrations of cultivated plants combined with the first sedaDNA signals of cultivation and pastoralism are consistent with evidence of the establishment of farming closer to the lake at around 300 BCE. These signals also correspond to the intensification of agriculture in southeastern Norway in the first centuries of the Early Iron Age. Applying an interdisciplinary approach allows us to reconstruct anthropogenic and environmental dynamics, and untangle effects of human land-use and environmental changes on vegetation dynamics in southeastern Norway during the Holocene.
Nowak, Michael; Birkeland, Siri; Mandáková, Terezie; Choudhury, Rimjhim Roy; Guo, Xinyi & Gustafsson, A Lovisa S [Show all 15 contributors for this article] (2020). The genome of Draba nivalis shows signatures of adaptation to the extreme environmental stresses of the Arctic. Molecular Ecology Resources. ISSN 1755-098X. doi: 10.1111/1755-0998.13280. Full text in Research Archive
Birkeland, Siri; Gustafsson, A Lovisa S; Brysting, Anne Krag; Brochmann, Christian & Nowak, Michael (2020). Multiple Genetic Trajectories to Extreme Abiotic Stress Adaptation in Arctic Brassicaceae. Molecular Biology and Evolution (MBE). ISSN 0737-4038. 37(7), p. 2052–2068. doi: 10.1093/molbev/msaa068. Full text in Research Archive Show summary
Abstract Extreme environments offer powerful opportunities to study how different organisms have adapted to similar selection pressures at the molecular level. Arctic plants have adapted to some of the coldest and driest biomes on Earth and typically possess suites of similar morphological and physiological adaptations to extremes in light and temperature. Here, we compare patterns of molecular evolution in three Brassicaceae species that have independently colonized the Arctic and present some of the first genetic evidence for plant adaptations to the Arctic environment. By testing for positive selection and identifying convergent substitutions in orthologous gene alignments for a total of 15 Brassicaceae species, we find that positive selection has been acting on different genes, but similar functional pathways in the three Arctic lineages. The positively selected gene sets identified in the three Arctic species showed convergent functional profiles associated with extreme abiotic stress characteristic of the Arctic. However, there was little evidence for independently fixed mutations at the same sites and for positive selection acting on the same genes. The three species appear to have evolved similar suites of adaptations by modifying different components in similar stress response pathways, implying that there could be many genetic trajectories for adaptation to the Arctic environment. By identifying candidate genes and functional pathways potentially involved in Arctic adaptation, our results provide a framework for future studies aimed at testing for the existence of a functional syndrome of Arctic adaptation in the Brassicaceae and perhaps flowering plants in general.
Nowak, Michael; Pedersen, Anne Tiril Myhre; Brysting, Anne Krag; Schrøder-Nielsen, Audun; Elven, Reidar & Bjorå, Charlotte Sletten (2020). Testing hypotheses of hybrid origins for two seashore species of Carex section Phacocystis (Cyperaceae). Botanical journal of the Linnean Society. ISSN 0024-4074. 194(1), p. 110–117. doi: 10.1093/botlinnean/boaa030. Full text in Research Archive Show summary
Abstract Taxonomists have proposed numerous hybrid species in plants, but to gain a better understanding of the role that hybridization may play in plant diversification, such taxonomic hypotheses must be tested using genomic data. In this study, we employ ddRAD sequence data to test taxonomic hypotheses of hybrid origins in Carex salina and C. ramenskii (Carex section Phacocystis). Sequence data from multiple Norwegian and Icelandic populations of the putative hybrid and parental species were generated for hundreds of ddRAD loci. These data were used to estimate geographical structuring of genetic diversity and admixture and to explicitly test for hybrid origins using several analytical approaches. Our results indicate recurrent hybrid origins for the populations of C. salina and C. ramenskii sampled in our study and show that these populations are characterized by high interspecific heterozygosity. Our results support the idea that hybridization may indeed play an important role in the diversification of lineages of Carex and highlight the important role that clonal propagation might play in maintaining hybrid populations. Future studies focusing on a broader geographical sampling would be needed to assess if the genetic structuring in these Nordic populations reflects range-wide patterns in these hybrid lineages.
Svoen, Mildrid Elvik; Müller, Eike; Brysting, Anne Krag; Kålås, Ingvil Henden & Eidesen, Pernille Bronken (2019). Female advantage? Investigating female frequency and establishment performance in high-arctic Silene acaulis. Botany. ISSN 1916-2790. 97(4), p. 245–261. doi: 10.1139/cjb-2018-0150. Full text in Research Archive Show summary
Many Arctic plants overcome limited time budgets and energy budgets by selfing, increasing the risk of inbreeding. Gynodioecious breeding systems allows for selfing by hermaphrodites, whereas enforced outcrossing through females lowers risk of inbreeding. Females persist due to female advantage in the system. Using the gynodioecious species Silene acaulis (L.) Jacq., we compared establishment performance and female frequency in 17 populations in open, sparsely vegetated habitats versus closed, denser vegetated habitats, across a regional climate gradient in high-Arctic Svalbard. For two populations, genetics were performed using microsatellites to compare inbreeding levels between habitats. As S. acaulis is a pioneer species, we expected denser vegetation to represent more competitive environments, reducing establishment performance and increasing female frequency due to female advantage. We expected similar responses to harsher regional climate. Establishment performance was reduced in closed habitats and harsher climate, but female frequency was slightly lower in closed habitats and did not differ between regional climates. High inbreeding levels may indicate that female advantage is counteracted by pollen limitation. However, female frequency increased with latitude. Lower sun angle at higher latitudes reduce the heat-trap effect of the cushion growth form, and female advantage might be expressed as response to reduced microclimate amelioration.
Evankow, Ann; Christie, Hartvig C; Hancke, Kasper; Brysting, Anne K; Junge, Claudia & Fredriksen, Stein [Show all 7 contributors for this article] (2019). Genetic heterogeneity of two bioeconomically important kelp species along the Norwegian coast. Conservation Genetics. ISSN 1566-0621. 20(3), p. 615–628. doi: 10.1007/s10592-019-01162-8. Full text in Research Archive Show summary
Knowledge of genetic diversity among wild populations is becoming increasingly important as more species are recognized for their bioeconomic value. Industrialization of natural resources, such as kelp in the marine shallow sublittoral zone through cultivation and wild-harvesting, may lead to extensive translocation and local population decimation. Without adequate resilience in the form of genetic diversity within and across populations and given the potential introduction of deleterious alleles from translocations, such anthropogenically pressured populations may not be able to sufficiently respond to future climate and other stressors. Here we provide an assessment of the genetic heterogeneity of two bioeconomically important kelp species, Laminaria hyperborea and Saccharina latissima, across the Norwegian coastal region from South (57°N) to North (78°N), by applying microsatellite genotyping. Isolation by distance was found for both kelp species when comparing genetic distance to geographic distance. L. hyperborea clustered into four distinct genetic groups corresponding to distinct geographical ecoregions, whereas S. latissima did not show equally strong geographical structuring but separated into three geographical clusters along the Norwegian coast. No genetic differentiation was found within the Norwegian Skagerrak region, corroborating previous findings. The identified genetic clustering of both kelp species supports the retention of established management regions along the Norwegian coast and argues for the continuation of a regional focused management plan for kelp resources. Further, the results demonstrate that care should be taken to prevent translocation of kelp between ecoregions in the ongoing industrialization of kelp cultivation, to maintain a healthy coastal ecosystem and sound natural population genetic diversity.
Bjerkan, Katrine; Hornslien, Karina Stensland; Johannessen, Ida Marie; Krabberød, Anders Kristian; Ekelenburg, Yuri Stephan van & Kalantarian, Maryam [Show all 11 contributors for this article] (2019). Genetic variation and temperature affects hybrid barriers during interspecific hybridization. The Plant Journal. ISSN 0960-7412. 101, p. 122–140. doi: 10.1111/tpj.14523. Full text in Research Archive Show summary
Genomic imprinting regulates parent‐specific transcript dosage during seed development and is mainly confined to the endosperm. Elucidation of the function of many imprinted genes has been hampered by the lack of corresponding mutant phenotypes, and the role of imprinting is mainly associated with genome dosage regulation or allocation of resources. Disruption of imprinted genes has also been suggested to mediate endosperm‐based post‐zygotic hybrid barriers depending on genetic variation and gene dosage. Here, we have analyzed the conservation of a clade from the MADS‐box type I class transcription factors in the closely related species Arabidopsis arenosa, A. lyrata, and A. thaliana, and show that AGL36‐like genes are imprinted and maternally expressed in seeds of Arabidopsis species and in hybrid seeds between outbreeding species. In hybridizations between outbreeding and inbreeding species the paternally silenced allele of the AGL36‐like gene is reactivated in the hybrid, demonstrating that also maternally expressed imprinted genes are perturbed during hybridization and that such effects on imprinted genes are specific to the species combination. Furthermore, we also demonstrate a quantitative effect of genetic diversity and temperature on the strength of the post‐zygotic hybridization barrier. Markedly, a small decrease in temperature during seed development increases the survival of hybrid F1 seeds, suggesting that abiotic and genetic parameters play important roles in post‐zygotic species barriers, pointing at evolutionary scenarios favoring such effects.
Thoen, Ella; Aas, Anders Bjørnsgard; Vik, Unni; Brysting, Anne Krag; Skrede, Inger & Carlsen, Tor [Show all 7 contributors for this article] (2019). A single ectomycorrhizal plant root system includes a diverse and spatially structured fungal community. Mycorrhiza. ISSN 0940-6360. 29(3), p. 167–180. doi: 10.1007/s00572-019-00889-z. Full text in Research Archive Show summary
Although only a relatively small proportion of plant species form ectomycorrhizae with fungi, it is crucial for growth and survival for a number of widespread woody plant species. Few studies have attempted to investigate the fine scale spatial structure of entire root systems of adult ectomycorrhizal (EcM) plants. Here, we use the herbaceous perennial Bistorta vivipara to map the entire root system of an adult EcM plant and investigate the spatial structure of its root-associated fungi. All EcM root tips were sampled, mapped and identified using a direct PCR approach and Sanger sequencing of the internal transcribed spacer region. A total of 32.1% of all sampled root tips (739 of 2302) were successfully sequenced and clustered into 41 operational taxonomic units (OTUs). We observed a clear spatial structuring of the root-associated fungi within the root system. Clusters of individual OTUs were observed in the younger parts of the root system, consistent with observations of priority effects in previous studies, but were absent from the older parts of the root system. This may suggest a succession and fragmentation of the root-associated fungi even at a very fine scale, where competition likely comes into play at different successional stages within the root system.
Mable, Barbara K.; Brysting, Anne Krag; Jørgensen, Marte Holten; Carbonell, Anna K.Z.; Kiefer, Christiane & Ruiz-Duarte, Paola [Show all 8 contributors for this article] (2018). Adding Complexity to Complexity: Gene Family Evolution in Polyploids. Frontiers in Ecology and Evolution. 6, p. 1–20. doi: 10.3389/fevo.2018.00114. Full text in Research Archive Show summary
Comparative genomics of non-model organisms has resurrected whole genome duplication (WGD) from being viewed as a somewhat obscure process that happens in plants to a primary driver of eukaryotic diversification. The shadow of past ploidy increases has left a strong signature of duplicated genes organized into gene families, even in small genomes that have undergone effectively complete rediploidization. Nevertheless, despite continually advancing technologies and bioinformatics pipelines, resolving the fate of duplicate genes remains a substantial challenge. For example, many important recognition processes are driven not only by allelic expansion through retention of duplicates but also by diversification and copy number variation. This creates technical difficulties with assembly to reference genomes and accurate interpretation of homology. Thus, relatively little is known about the impacts of recent polyploidization and hybridization on the evolution of gene families under selective forces that maintain diversity, such as balancing selection. Here we use a complex of species and ploidy levels in the genus Arabidopsis (A. lyrata and A. arenosa) as a model to investigate the evolutionary dynamics of a large and complicated gene family known to be under strong balancing selection: the receptor-like kinases, which include the female component of genetically controlled self-incompatibility. Specifically, we question: (1) How does diversity of S-receptor kinase (SRK) alleles in tetraploids compare to that in their close diploid relatives? (2) Is there increased trans-specific polymorphism (i.e., sharing of alleles that transcend speciation, characteristic of balancing selection) in tetraploids compared to diploids due to the higher number of copies they carry? (3) Do these highly variable loci show evidence of introgression among extant species/ploidy levels within or outside known zones of hybridization? (4) Is there evidence for copy number variation among paralogs? We use this example to highlight specific issues to consider when interpreting gene family evolution, particularly in relation to polyploids but also more generally in diploids. We conclude with recommendations for strategies to address the challenges of resolving such complex loci in the future, using advances in deep sequencing approaches.
Raclariu, Ancuta Cristina; Tebrencu, Carmen Elena; Ichim, Mihael Cristin; Ciuperca, Oana Teodora; Brysting, Anne Krag & Boer, Hugo de (2018). What's in the box? Authentication of Echinacea herbal products using DNA metabarcoding and HPTLC. Phytomedicine. ISSN 0944-7113. 44, p. 32–38. doi: 10.1016/j.phymed.2018.03.058. Full text in Research Archive
Lafon-Placette, Clément; Johannessen, Ida Marie; Hornslien, Karina Stensland; Ali, Mohammad F.; Bjerkan, Katrine & Bramsiepe, Jonathan [Show all 11 contributors for this article] (2017). Endosperm-based hybridization barriers explain the pattern of gene flow between Arabidopsis lyrata and Arabidopsis arenosa in Central Europe. Proceedings of the National Academy of Sciences of the United States of America (PNAS). ISSN 0027-8424. 114(6), p. E1027–E1035. doi: 10.1073/pnas.1615123114. Full text in Research Archive
Birkeland, Siri; Skjetne, Idunn Elisabeth Borgen; Brysting, Anne Krag; Elven, Reidar & Alsos, Inger Greve (2017). Living on the edge: conservation genetics of seven thermophilous plant species in a high Arctic archipelago. AoB Plants. 9(1). doi: 10.1093/aobpla/plx001. Full text in Research Archive Show summary
Small, isolated and/or peripheral populations are expected to harbour low levels of genetic variation and may therefore have reduced adaptability to environmental change, including climate warming. In the Arctic, global warming has already caused vegetation change across the region and is acting as a significant stressor on Arctic biodiversity. Many of the rare plants in the Arctic are relicts from early Holocene warm periods, but their ability to benefit from the current warming is dependent on the viability of their populations. We therefore examined Amplified Fragment Length Polymorphism (AFLP) data from regional red listed vascular plant species in the High Arctic archipelago of Svalbard and reference populations from the main distribution area of: (1) Botrychium lunaria, (2) Carex capillaris ssp. fuscidula, (3) Comastoma tenellum, (4) Kobresia simpliciuscula ssp. subholarctica, (5) Ranunculus wilanderi, (6) Sibbaldia procumbens and (7) Tofieldia pusilla. In addition, we gathered population size data in Svalbard. The Svalbard populations had low genetic diversity and distinctiveness and few or no private markers compared to populations outside the archipelago. This is similar to observations in other rare species in Svalbard and the genetic depletion may be due to an initial founder effect and/or a genetic bottleneck caused by late Holocene cooling. There seems to be limited gene flow from other areas and the Svalbard populations should therefore be considered as demographically independent management units. Overall, these management units have small and/or few populations and are therefore prone to stochastic events which may further increase vulnerability to inbreeding depression, loss of genetic variation, and reduced evolutionary potential. Our results support theory predicting lower levels of genetic diversity in small, isolated and/or peripheral populations and may be of importance for management of other rare plant species in the Arctic.
Brandrud, Marie Kristine; Paun, Ovidiu; Lorenzo, Maria Teresa; Nordal, Inger & Brysting, Anne Krag (2017). RADseq provides evidence for parallel ecotypic divergence in the autotetraploid Cochlearia officinalis in Northern Norway. Scientific Reports. 7. doi: 10.1038/s41598-017-05794-z. Full text in Research Archive Show summary
Speciation encompasses a continuum over time from freely interbreeding populations to reproductively isolated species. Along this process, ecotypes – the result of local adaptation – may be on the road to new species. We investigated whether three autotetraploid Cochlearia officinalis ecotypes, adapted to different habitats (beach, estuary, spring), are genetically differentiated and result from parallel ecotypic divergence in two distinct geographical regions. We obtained genetic data from thousands of single nucleotide polymorphisms (SNPs) from restriction-site associated DNA sequencing (RADseq) and from six microsatellite markers for 12 populations to assess genetic divergence at ecotypic, geographic and population level. The genetic patterns support differentiation among ecotypes as suggested by morphology and ecology. The data fit a scenario where the ancestral beach ecotype has recurrently and polytopically given rise to the estuary and spring ecotypes. Several ecologically-relevant loci with consistent non-random segregating patterns are identified across the recurrent origins, in particular around genes related to salt stress. Despite being ecologically distinct, the Cochlearia ecotypes still represent an early stage in the process of speciation, as reproductive isolation has not (yet) developed. A sequenced annotated genome is needed to specifically target candidate genes underlying local adaptation.
Nielsen, Anders; Reitan, Trond; Rinvoll, Andreas & Brysting, Anne Krag (2017). Effects of competition and climate on a crop pollinator community. Agriculture, Ecosystems & Environment. ISSN 0167-8809. 246, p. 253–260. doi: 10.1016/j.agee.2017.06.006. Full text in Research Archive Show summary
Plant-pollinator interactions are ubiquitous in nature where both wild and domesticated pollinators interact with wild plant communities and entomophilous crops. Honeybees are important pollinators in many crop systems, but recent declines in honeybee stocks in Europe and the US have caused concern about the sustainability of crop systems solely depending on honeybees. In addition, several studies have shown that honeybees might negatively affect native pollinator populations, bumblebees in particular. Here we have studied flower visitation to two raspberry farms and surrounding wildflower communities in SE Norway. Bumblebees were excluded from the raspberry field by means of exploitative competition from honeybees ( > 97% of flower visits in the raspberry fields were conducted by honeybees). More than 55% of the visits recorded in wild plant communities surrounding the farms were conducted by bumblebees, showing that bumblebees were present in the system. Pollinator taxa were affected differently by temperature; honeybee visits showed a unimodal relationship with maximum flower visitation activity at a temperature of 24.1 °C, while flower visits by bumblebees showed a positive, linear relationship with temperature. The effect of temperature was much weaker for bumblebees than for honeybees (∼2.2% of the variation was explained by temperature, compared to ∼46% for honeybees). Farming practice affected flower visitation, as flowers within growing tunnels received fewer visits. However, the number of flower visits, also within the growing tunnels, was far above what other studies have shown to be sufficient for optimal pollination in raspberry. We conclude that the raspberry fields were sufficiently pollinated by honeybees but that the system should be considered vulnerable as it is solely dependent on this particular pollinator species. The honeybees were sensitive to ambient temperature suggesting that they might suffer more from future climate change than bumblebees.
Raclariu, Ancuta Cristina; Mocan, Andrei; Popa, Madalina Oana; Vlase, Laurian; Ichim, Mihael Cristi & Crisan, Gianina [Show all 8 contributors for this article] (2017). Veronica officinalis product authentication using DNA metabarcoding and HPLC-MS reveals widespread adulteration with Veronica chamaedrys. Frontiers in Pharmacology. 8, p. 1–13. doi: 10.3389/fphar.2017.00378. Full text in Research Archive Show summary
Studying herbal products derived from local and traditional knowledge and their value chains is one of the main challenges in ethnopharmacology. The majority of these products have a long history of use, but non-harmonized trade and differences in regulatory policies between countries impact their value chains and lead to concerns over product efficacy, safety and quality. Veronica officinalis L. (common speedwell), a member of Plantaginaceae family, has a long history of use in European traditional medicine, mainly in central eastern Europe and the Balkans. However, no specified control tests are available either to establish the quality of derived herbal products or for the discrimination of its most common substitute, V. chamaedrys L. (germander speedwell). In this study, we use DNA metabarcoding and high performance liquid chromatography coupled with mass spectrometry (HPLC-MS) to authenticate sixteen V. officinalis herbal products and compare the potential of the two approaches to detect substitution, adulteration and the use of unreported constituents. HPLC-MS showed high resolution in detecting phytochemical target compounds, but did not enable detection of specific plant species in the products. DNA metabarcoding detected V. officinalis in only 15% of the products, whereas it detected V. chamaedrys in 62% of the products. The results confirm that DNA metabarcoding can be used to test for the presence of Veronica species, and detect substitution and/or admixture of other Veronica species, as well as simultaneously detect all other species present. Our results confirm that none of the herbal products contained exactly the species listed on the label, and all included substitutes, contaminants or fillers. This study highlights the need for authentication of raw herbals along the value chain of these products. An integrative methodology can assess both the quality of herbal products in terms of target compound concentrations and species composition, as well as admixture and substitution with other chemical compounds and plants.
Raclariu, Ancuta Cristina; Paltinean, Ramona; Vlase, Laurian; Labarre, Aurélie; Manzanilla, Vincent & Ichim, Mihael Cristin [Show all 9 contributors for this article] (2017). Comparative authentication of Hypericum perforatum herbal products using DNA metabarcoding, TLC and HPLC-MS. Scientific Reports. 7(1). doi: 10.1038/s41598-017-01389-w. Full text in Research Archive Show summary
Many herbal products have a long history of use, but there are increasing concerns over product efficacy, safety and quality in the wake of recent cases exposing discrepancies between labeling and constituents. When it comes to St. John’s wort (Hypericum perforatum L.) herbal products, there is limited oversight, frequent off-label use and insufficient monitoring of adverse drug reactions. In this study, we use amplicon metabarcoding (AMB) to authenticate 78 H. perforatum herbal products and evaluate its ability to detect substitution compared to standard methods using thin-layer chromatography (TLC) and high performance liquid chromatography coupled with mass spectrometry (HPLC-MS). Hypericum perforatum was detected in 68% of the products using AMB. Furthermore, AMB detected incongruence between constituent species and those listed on the label in all products. Neither TLC nor HPLC-MS could be used to unambiguously identify H. perforatum. They are accurate methods for authenticating presence of the target compounds, but have limited efficiency in detecting infrageneric substitution and do not yield any information on other plant ingredients in the products. Random post-marketing AMB of herbal products by regulatory agencies could raise awareness among consumers of substitution and would provide an incentive to manufacturers to increase quality control from raw ingredients to commercialized products.
Oxelman, Bengt; Brysting, Anne Krag; Jones, Graham R; Marcussen, Thomas; Oberprieler, Christoph & Pfeil, Bernard E. (2017). Phylogenetics of Allopolyploids. Annual Review of Ecology, Evolution and Systematics. ISSN 1543-592X. 48, p. 543–557. doi: 10.1146/annurev-ecolsys-110316-022729. Full text in Research Archive Show summary
We give an overview of recently developed methods to reconstruct phylogenies of taxa that includes allopolyploids which have originated in relatively recent times, i.e., such that at least some of the parental lineages of lower ploidy levels are not extinct, and that there is clear ploidy information shown by variation in chromosome counts. We review how these methods have been applied to empirical data. The challenges are discussed and prospects for the future are outlined. The review includes a description of a new version of the AlloppNET method, which now can handle any number of species at the diploid and tetraploid level, and any num,ber of hybridisations. AlloppNET is an extension of the *BEAST model which can handle allotetraploids.
Bjorå, Charlotte Sletten; Elden, Marte; Nordal, Inger; Brysting, Anne Krag; Awas, Tesfaye & Sebsebe, Demissew [Show all 7 contributors for this article] (2017). Speciation in the genera Anthericum and Chlorophytum (Asparagaceae) in Ethiopia — a molecular phylogenetic approach. Phytotaxa. ISSN 1179-3155. 297(2), p. 139–156. doi: 10.11646/phytotaxa.297.2.2. Full text in Research Archive Show summary
Sister group relations of Ethiopian species of Anthericum and Chlorophytum and variation patterns in the C. gallabatense and C. comosum complexes are studied using molecular phylogenetic analyses, morphometrics, and scanning electron microscopy of seed surfaces. Our results indicate that molecular data largely support previous morphological conclusions, and that speciation has occurred in Ethiopia at least three times in Anthericum and repeatedly within different subclades of Chlorophytum. Areas particularly rich in endemic species are the lowland area around Bale Mountains in SE Ethiopia and in the Beninshangul Gumuz regional state in W Ethiopia near the border to Sudan. A new species, Chlorophytum mamillatum sp. nov., is described, and the names Chlorophytum tordense Chiov. and Chlorophytum tetraphyllum f. are re-erected.
Sjøtun, Kjersti; Heesch, Svenja; Lluch, Jordi Rull; Martín, Rafael Martín; Garreta, Amelia Gómez & Brysting, Anne Krag [Show all 7 contributors for this article] (2017). Unravelling the complexity of salt marsh ‘Fucus cottonii’ forms (Phaeophyceae, Fucales). European journal of phycology. ISSN 0967-0262. 52(3), p. 360–370. doi: 10.1080/09670262.2017.1309688. Full text in Research Archive Show summary
Genetic affiliation, nuclear DNA content, and gamete functioning were examined in small salt marsh Fucus from three localities in western Ireland. Individuals with small and dioecious receptacles were found at all localities, but production of germlings was only evident at Locality 1. Here, the Fucus vegetation formed a morphological cline from F. vesiculosus with bladders in the mid-intertidal to small Fucus individuals lacking bladders in the salt marsh of the upper intertidal. Measurements of nuclear DNA content ranged from 1–1.8 pg at this locality, with F. vesiculosus individuals in the lower range. At the two other localities, the small salt marsh Fucus consisted of distinct morphological entities. Microsatellite analyses revealed that individuals at Locality 2 were derived mainly from F. vesiculosus, whereas those from Locality 3 were hybrids between F. vesiculosus and F. spiralis with greatest affiliation to F. spiralis. While the small salt marsh Fucus forms from Locality 2 had high nuclear DNA content (c. 4 pg) and were probably octoploids, the small salt marsh Fucus from Locality 3 formed two groups: one with high (3.9–4.6 pg) and one with low (1.5–1.9 pg) nuclear DNA content. Nuclear DNA content measured in individuals from Locality 3 varied between 1.1–2.8 pg in F. vesiculosus and 2–3.5 pg in F. spiralis, and showed a more or less stepwise increase in both species, consistent with polyploidy. We hypothesize that the small salt marsh Fucus forms originate from genome size changes in the parental taxa.
Pedersen, Anne Tiril Myhre; Nowak, Michael; Brysting, Anne Krag; Elven, Reidar & Bjorå, Charlotte Sletten (2016). Hybrid Origins of Carex rostrata var. borealis and C. stenolepis, Two Problematic Taxa in Carex section Vesicariae (Cyperaceae). PLOS ONE. 11(10), p. 1–18. doi: 10.1371/journal.pone.0165430. Full text in Research Archive Show summary
Hybridization is frequent in the large and ecologically significant genus Carex (Cyperaceae). In four important sections of the northern regions (Ceratocystis, Glareosae, Phacocystis and Vesicariae), the frequent occurrence of hybrids often renders the identification of “pure” species and hybrids difficult. In this study we address the origins and taxonomic rank of two taxa of section Vesicariae: Carex rostrata var. borealis and C. stenolepis. The origin and taxonomic status of C. stenolepis has been the subject of substantial debate over the years, whereas C. rostrata var. borealis has received very little attention in the years since its first description in the 19th century. By performing an extensive sampling of relevant taxa from a broad distribution range, and analyzing data from fifteen microsatellite loci developed specifically for our study together with pollen stainability measures, we resolve the hybrid origins of C. rostrata var. borealis and C. stenolepis and provide new insights into this taxonomically challenging group of sedges. Our results are in accordance with previous findings suggesting that C. stenolepis is a hybrid between C. vesicaria and C. saxatilis. They are also in accordance with a previous proposition that C. rostrata var. borealis is a hybrid between C. rostrata and C. rotundata, and furthermore suggest that both hybrids are the result of multiple, recent (i.e., postglacial) hybridization events. We found little evidence for successful sexual reproduction within C. rostrata var. borealis and C. stenolepis, but conclude that the common and recurrent, largely predictable occurrence of these taxa justifies accepting both hybrids as hybrid species with binomial names. There are, however, complications as to types and priority names, and we therefore choose to address these problems in a separate paper.
Olonova, Marina; Gussarova, Galina; Brysting, Anne Krag & Mezina, Natalia S. (2016). Introgressive hybridization in mesomorphic bluegrasses, Poa section Stenopoa, in western Siberia. Annales Botanici Fennici. ISSN 0003-3847. 53(1-2), p. 43–55. doi: 10.5735/085.053.0210. Full text in Research Archive
Marcussen, Thomas; Heier, Lise; Brysting, Anne Krag; Oxelman, Bengt & Jakobsen, Kjetill Sigurd (2015). From gene trees to a dated allopolyploid network: insights from the angiosperm genus Viola (Violaceae). Systematic Biology. ISSN 1063-5157. 64(1), p. 84–101. doi: 10.1093/sysbio/syu071. Full text in Research Archive
Willerslev, E; Davison, J; Moora, M; Zobel, M; Coissac, E & Edwards, ME [Show all 50 contributors for this article] (2014). Fifty thousand years of Arctic vegetation and megafaunal diet. Nature. ISSN 0028-0836. 506(7486), p. 47–51. doi: 10.1038/nature12921. Full text in Research Archive
Westengen, Ola Tveitereid; Okongo, Mark Atam; Onek, Leo; Berg, Trygve; Upadhyaya, Hari & Birkeland, Siri [Show all 10 contributors for this article] (2014). Ethnolinguistic structuring of sorghum genetic diversity in Africa and the role of local seed systems. Proceedings of the National Academy of Sciences of the United States of America (PNAS). ISSN 0027-8424. 111(39), p. 14100–14105. doi: 10.1073/pnas.1401646111. Full text in Research Archive Show summary
Sorghum is a drought-tolerant crop with a vital role in the livelihoods of millions of people in marginal areas. We examined genetic structure in this diverse crop in Africa. On the continentwide scale, we identified three major sorghum populations (Central, Southern, and Northern) that are associated with the distribution of ethnolinguistic groups on the continent. The codistribution of the Central sorghum population and the Nilo-Saharan language family supports a proposed hypothesis about a close and causal relationship between the distribution of sorghum and languages in the region between the Chari and the Nile rivers. The Southern sorghum population is associated with the Bantu languages of the Niger-Congo language family, in agreement with the farminglanguage codispersal hypothesis as it has been related to the Bantu expansion. The Northern sorghum population is distributed across early Niger-Congo and Afro-Asiatic language family areas with dry agroclimatic conditions. At a finer geographic scale, the genetic substructure within the Central sorghum population is associated with language-group expansions within the Nilo-Saharan language family. A case study of the seed system of the Pari people, a Western-Nilotic ethnolinguistic group, provides a window into the social and cultural factors involved in generating and maintaining the continent-wide diversity patterns. The age-grade system, a cultural institution important for the expansive success of this ethnolinguistic group in the past, plays a central role in the management of sorghum landraces and continues to underpin the resilience of their traditional seed system.
Westengen, Ola Tveitereid; Ring, Kristoffer Hofaker; Berg, Paul Ragnar & Brysting, Anne Krag (2014). Modern maize varieties going local in the semi-arid zone in Tanzania. BMC Evolutionary Biology. 14(1), p. 1–12. doi: 10.1186/1471-2148-14-1. Full text in Research Archive Show summary
Background: Maize is the most produced crop in Sub-Saharan Africa, but yields are low and climate change is projected to further constrain smallholder production. The current efforts to breed and disseminate new high yielding and climate ready maize varieties are implemented through the formal seed system; the chain of public and private sector activities and institutions that produce and release certified seeds. These efforts are taking place in contexts currently dominated by informal seed systems; local and informal seed management and exchange channels with a long history of adapting crops to local conditions. We here present a case study of the genetic effects of both formal and informal seed management from the semi-arid zone in Tanzania. Results: Two open pollinated varieties (OPVs), Staha and TMV1, first released by the formal seed system in the 1980s are cultivated on two-thirds of the maize fields among the surveyed households. Farmer-recycling of improved varieties and seed selection are common on-farm seed management practices. Drought tolerance and high yield are the most important characteristics reported as reason for cultivating the current varieties as well as the most important criteria for farmers’ seed selection. Bayesian cluster analysis, PCA and FST analyses based on 131 SNPs clearly distinguish between the two OPVs, and despite considerable heterogeneity between and within seed lots, there is insignificant differentiation between breeder’s seeds and commercial seeds in both OPVs. Genetic separation increases as the formal system varieties enter the informal system and both hybridization with unrelated varieties and directional selection probably play a role in the differentiation. Using a Bayesian association approach we identify three loci putatively under selection in the informal seed system. Conclusions: SOur results suggest that the formal seed system in the study area distributes seed lots that are true to type. We suggest that hybridization and directional selection differentiate farmer recycled seed lots from the original varieties and potentially lead to beneficial creolization. Access to drought tolerant OPVs in combination with farmer seed selection is likely to enhance seed system security and farmers’ adaptive capacity in the face of climate change.
Westengen, Ola Tveitereid & Brysting, Anne Krag (2014). Crop adaptation to climate change in the semi-arid zone in Tanzania: the role of genetic resources and seed systems. Agriculture & Food Security. 3(3). doi: 10.1186/2048-7010-3-3. Full text in Research Archive Show summary
Background: Rural livelihoods relying on agriculture are particularly vulnerable to climate change. Climate models project increasingly negative effects on maize and sorghum production in sub-Saharan Africa. We present a case study of the role of genetic resources and seed systems in adapting to climatic stress from the semi-arid agroecological zone in Tanzania. Results: Crop adaptation, switching to more drought-tolerant crop species or varieties, is an important adaptation strategy within a diverse portfolio of livelihood responses to climatic stress. Crop adaptation involves the adoption of improved maize varieties combined with continued use of local varieties of both maize and sorghum. Regression modelling shows that households receiving the extension service and owning livestock are more likely to switch to drought-tolerant varieties as a response to climatic stress than those without access to these assets. The seed system in the study area consists of both formal and informal elements. The informal channels supply the highest quantities of both sorghum and maize seeds. Recycling of improved varieties of maize is common and the majority of households practice seed selection. Detailed assessment of the three different categories of genetic resources – local, improved and farmer-recycled varieties – reveals that drought tolerance is more frequently reported as a reason for growing local varieties than for growing improved varieties of maize and sorghum. The significantly later maturity reported for local varieties compared to the improved varieties bred to have a short growing cycle indicates that households distinguish between drought-tolerance and drought-avoidance traits. Conclusions: Seed system perspectives on crop adaptation offer insights into the complex ways crop adaptation is realized at the livelihood level. The integration of informal and formal seed system elements is important for the adaptive capacity of agriculture-based livelihoods. Our findings highlight the value and importance of location-specific information about crop variety use for arriving at realistic recommendations in impact and adaptation studies.
Moe, Therese Fosholt; Brysting, Anne Krag; Andersen, Tom; Schneider, Susanne Claudia; Kaste, Øyvind & Hessen, Dag Olav (2013). Nuisance growth of Juncus bulbosus: the roles of genetics and environmental drivers tested in a large-scale survey. Freshwater Biology. ISSN 0046-5070. 58(1), p. 114–127. doi: 10.1111/fwb.12043. Full text in Research Archive Show summary
1. Invasive species can transform aquatic ecosystems, and the nuisance growth of the freshwater macrophyte Juncus bulbosus has become a problem in many lakes and rivers in northern Europe. It affects biodiversity strongly and conflicts with human uses, not least compromising the generation of hydroelectricity. The causes of the proliferation of these massive stands of J. bulbosus are not finally resolved, however. 2. In this study, a wide range of catchment, lake and sediment parameters (n = 34) were assessed for 139 lakes in Southern Norway, with the aim of explaining the presence or absence of J. bulbosus and to assess potential drivers behind its prolific growth. 3. Juncus bulbosus was more often present in lakes with lower pH and phosphate concentrations, and a higher element ratio of dissolved inorganic nitrogen (DIN) to total phosphorus (DIN : TotP). 4. Despite the many parameters measured across substantial environmental gradients, none explained nuisance growth. Genetic screening (amplified fragment length polymorphism fingerprinting) of plants from a subset of lakes and additional river sites also showed no genetic differences between the various growth forms. A macrophyte trophic index, however, suggested that the most problematic growth occurred in the most oligotrophic lakes. 5. The lack of consistent patterns may reflect either factors not assessed in our survey, or that the current extension of stands represents a gradual cumulative response over time, not characterised effectively in our snapshot survey. Nevertheless, we can now exclude some putative causes of nuisance growth, including in particular genetics and N‐deposition.
Fang, Yao; Vik, Unni; Brysting, Anne Krag; Carlsen, Tor; Halvorsen, Rune & Kauserud, Håvard (2013). Substantial compositional turnover of fungal communities in an alpine ridge-to-snowbed gradient. Molecular Ecology. ISSN 0962-1083. 22(19), p. 5040–5052. doi: 10.1111/mec.12437. Full text in Research Archive
Jørgensen, Marte Holten; Lagesen, Karin; Mable, Barbara & Brysting, Anne Krag (2012). Using high-throughput sequencing to investigate the evolution of self-incompatibility genes in the Brassicaceae: strategies and challenges. Plant Ecology & Diversity. ISSN 1755-0874. 5(4), p. 473–484. doi: 10.1080/17550874.2012.748098. Full text in Research Archive

View all works in NVA

Marie-Orleach, Lucas; Glémin, Sylvain; Brandrud, Marie Kristine; Brysting, Anne Krag; Gustafsson, Lovisa & Seid, Abel Gizaw [Show all 9 contributors for this article] (2024). How does selfing affect the pace and process of speciation? Full text in Research Archive
Huseby, Lise Grønnerød; Brysting, Anne Krag; Brochmann, Christian; Gustafsson, A Lovisa S & Leppala, Johanna (2024). Testing the snowball theory on intraspecific reproductive isolation in Arabidopsis lyrata. Full text in Research Archive
Gusarova, Galina; Mjøen, Hedvig Elisabeth; Corti, Magali; Mahé, Frédéric; Meyer, Pernille & Steinthorsdottir, Lilja [Show all 22 contributors for this article] (2024). Bridging past and present: From dietary metabarcoding of large herbivores towards broad scale biodiversity analyses. Full text in Research Archive
Boessenkool, Sanne; Bruch, Angela A.; Schure, Anna Theresia Maria ter; Gasparyan, Boris; Bussmann, Rainer W. & Brysting, Anne Krag [Show all 10 contributors for this article] (2023). Sedimentary ancient DNA metabarcoding for the recognition of Paleolithic human plant use. Full text in Research Archive
Birkeland, Siri; Gustafsson, A Lovisa S; Gizaw, Abel; Chala, Desalegn; Fraccasetti, Marco & Brazier, Thomas [Show all 13 contributors for this article] (2022). What drives the rapid buildup of sterility barriers in the Arctic crucifer Draba nivalis? Full text in Research Archive
Brandrud, Marie Kristine; Paun, Ovidiu; Lorenzo, Maria Teresa; Nordal, Inger & Brysting, Anne Krag (2022). Parallel ecotypic divergence in the autotetraploid Cochlearia officinalis in Northern Norway. Full text in Research Archive
Alling, Renate; Brysting, Anne Krag; Grini, Paul; Bjerkan, Katrine & Myking, Ida Velle (2022). Environmental and genetic factors affecting endosperm based post-zygotic hybridization barriers. Full text in Research Archive Show summary
Proper development of the triploid endosperm is vital for seed viability. During the early stages of development, the endosperm works as a nutrient sink, accumulating sugars from the surrounding tissues. During this developmental phase, endosperm division is devoid of cytokinesis, resulting in a syncytium. After sufficient accumulation of nutrients, the endosperm nuclei undergo cellularization, switching to serve as a nutrient source for the embryo. Tight regulation of cellularization is therefore vital for embryo development. Crosses between Arabidopsis thaliana as maternal contributor and A. arenosa as pollen donor cause late cellularization and reduced germination rate in hybrid seeds. Here we show the opposite cellularization phenotype in hybrid seeds when using A. lyrata as pollen donor also resulting in low germination rate. Stage specific endosperm reporters display ectopic expression in developing hybrid endosperm confirming disturbance of the source-sink endosperm phase change. We also observe accession genotype as well as single loci effects on the severity of the barrier. Interestingly, we found that temperature can alleviate this hybridization barrier in opposite directions depending on whether the hybrid seed exhibit early or late endosperm cellularization. We postulate that temperature dependency might be a general mechanism affecting endosperm-based hybridization barriers.
Tjessem, Ingrid Vesterdal; Eidesen, Pernille Bronken & Brysting, Anne Krag (2021). Polyploidy in Saxifraga oppositifolia. A shift in reproductive parameters, a result of environmental adaptations? Full text in Research Archive
Schure, Anneke ter; Bajard, Manon Julietto Andree; Loftsgarden, Kjetil; Høeg, Helge Irgens; Ballo, Eirik Magnus Gottschalk & Bakke, Jostein [Show all 12 contributors for this article] (2021). Disentangling anthropogenic and environmental drivers of biological change in southeastern Norway during the Holocene. Full text in Research Archive
Schure, Anneke ter; Bajard, Manon Julietto Andree; Loftsgarden, Kjetil; Høeg, Helge Irgens; Ballo, Eirik Magnus Gottschalk & Bakke, Jostein [Show all 12 contributors for this article] (2021). Anthropogenic and environmental drivers of biological change in southeastern Norway during the Holocene. Full text in Research Archive
Birkeland, Siri; Slotte, Tanja; Brochmann, Christian; Brysting, Anne Krag; Gustafsson, Lovisa & Nowak, Michael D (2021). What can the cold-induced transcriptomes of Arctic Brassicaceae tell us about the evolution of cold tolerance? Full text in Research Archive
Gullvåg, Rebekka; Vollsnes, Ane Victoria; Bryn, Anders; Brysting, Anne Krag & Vatne, Astrid (2021). Effects of high-latitude light conditions on stomatal conductance and photosynthesis in white clover (Trifolium repens). Full text in Research Archive
Bjerkan, Katrine; Butenko, Melinka Alonso & Brysting, Anne Krag (2020). The weed that conquered plant scientists: the model organism Arabidopsis thaliana. NBS-nytt. ISSN 0801-3535. 1, p. 8–11. Full text in Research Archive
Brysting, Anne Krag (2019). Speciation and reproductive barriers. Full text in Research Archive
Huseby, Lise Grønnerød; Nowak, Michael; Gustafsson, A Lovisa S; Brochmann, Christian & Brysting, Anne Krag (2019). How fast does the Speciation Clock tick? Full text in Research Archive Show summary
Species are the most fundamental unit in nature, yet we know surprisingly little about how long it takes for new, reproductively isolated species to originate and what factors influence the rate of speciation. Speciation depends on the evolution of reproductive barriers that make individuals reproductively isolated from one another. One potential factor that could impact how fast these reproductive barriers occur is mating system. It has been suggested that self-fertilization, a common mating system both in wild and cultivated plants and also found in animals, can drive the evolution of postzygotic reproductive isolation, and thus create new species. Our aim is to test whether selfing species diverge into new species faster than outcrossing species. We will therefore test the rate at which reproductive barriers occur within species with different mating systems, we will target one selfing and one outcrossing plant species and identify the number of loci responsible for reproductive isolation between populations representing different degrees of population divergence. For this project we will use two plant species, the selfer Draba nivalis and the outcrosser Arabidopsis lyrata and perform quantitative trait locus (QTL) mapping experiments aimed at identifying the number of loci responsible for reproductive isolation between populations representing different degrees of population divergence. For this we need to create intraspecific crosses and produce large F2 populations for genotyping and phenotyping. We will then test the ‘snowball effect’ in both species and compare the rate of accumulation of genes that contribute to reproductive isolation.
Birkeland, Siri; Gustafsson, A Lovisa S; Brysting, Anne Krag; Brochmann, Christian & Nowak, Michael (2019). Same destination, but different roads? Overarching, but limited fine-scale molecular convergence in Arctic crucifers. Full text in Research Archive
Gusarova, Galina; Kamenova, Stefaniya; Coissac, Eric; Meyer, Pernille; Steinthorsdottir, Lilja & Loe, Leif Egil [Show all 14 contributors for this article] (2019). Multi-locus DNA metabarcoding of diet provides new insights into the ecology and trophic interactions of a keystone herbivore species. Full text in Research Archive
Kenich, Håkon Muland; Bjerkan, Katrine; Bramsiepe, Jonathan; Grini, Paul Eivind & Brysting, Anne Krag (2019). An investigation of potential hybridisation barriers in Cochlearia / Scurvygrasses. Full text in Research Archive
Bjerkan, Katrine; Hornslien, Karina Stensland; Johannessen, Ida Marie; Ekelenburg, Yuri Stephan van; Bramsiepe, Jonathan & Brysting, Anne Krag [Show all 7 contributors for this article] (2019). Temperature and genetic variation alter strength of the post-zygotic endosperm based barrier between A. thaliana and A.arenosa. Full text in Research Archive
Johannessen, Ida Marie; Hornslien, Karina Stensland; Krabberød, Anders Kristian; Bramsiepe, Jonathan; Brysting, Anne Krag & Grini, Paul Eivind (2018). The Genetic Basis of Post-Zygotic Hybridization Barriers Between Arabidopsis lyrata and A. arenosa. Full text in Research Archive
Birkeland, Siri; Gustafsson, A Lovisa S; Brysting, Anne Krag; Brochmann, Christian & Nowak, Michael (2018). Testing for convergent signatures of selection in Arctic plants. Full text in Research Archive
Meyer, Pernille & Brysting, Anne Krag (2017). Identification of seasonal changes in diet of the Svalbard Reindeer (Rangifer tarandus platyrhynchus) and validation of DNA metabarcoding as a tool for diet analysis. Full text in Research Archive
Steinthorsdottir, Lilja & Brysting, Anne Krag (2017). Investigating trophic interactions among arctic herbivorous species in a rapidly changing Arctic tundra using DNA metabarcoding and microhistology. Full text in Research Archive
Stedje, Brita; Mwafongo, Elizabeth Brighton Mvula & Brysting, Anne Krag (2017). Subgeneric delimitation and character evolution in Albuca subg. Albuca (Asparagaceae subfamily Scilloideae). Full text in Research Archive
Bruholt, Eirin & Brysting, Anne Krag (2017). The systematic relationships of the North Atlantic and Atlantic Cochlearia L. taxa. Full text in Research Archive
Birkeland, Siri; Gustafsson, A Lovisa S; Slotte, Tanja; Brysting, Anne Krag; Brochmann, Christian & Nowak, Michael (2017). Testing for convergent molecular evolution in Arctic plants. Full text in Research Archive
Johannessen, Ida Marie; Lafon-Placette, Clément; Hornslien, Karina Stensland; Bramsiepe, Jonathan; Bjerkan, Katrine & Brysting, Anne Krag [Show all 8 contributors for this article] (2017). The effect of gene and genome dosage on hybridization barriers in Arabidopsis lyrata and Arabidospsis arenosa. Full text in Research Archive
Johannessen, Ida Marie; Hornslien, Karina Stensland; Krabberød, Anders Kristian; Bramsiepe, Jonathan; Brysting, Anne Krag & Grini, Paul Eivind (2017). The genetic basis of post-zygotic hybridization barriers between Arabidopsis lyrata and A. arenosa. Full text in Research Archive
Brysting, Anne Krag & Grini, Paul Eivind (2017). The molecular basis of postzygotic hybridization barriers in plants. Full text in Research Archive
Brysting, Anne Krag (2016). Hvordan nye arter kan oppstå over natten. Full text in Research Archive
Nielsen, Anders & Brysting, Anne Krag (2016). Blomstene og biene - evolusjon og økologi. Full text in Research Archive
Fagerli, Lisa Amalie Lunde; Bårdsen, Bård-Jørgen; Brysting, Anne Krag & Nielsen, Anders (2016). Plant-pollinator interactions along an elevation gradient in northern Norway. Full text in Research Archive
Fagerli, Lisa Amalie Lunde; Bårdsen, Bård-Jørgen; Brysting, Anne Krag & Nielsen, Anders (2016). Plant-pollinator interactions along an elevation gradient in Northern Norway. Full text in Research Archive
Brandrud, Marie Kristine; Paun, Ovidiu; Nordal, Inger; Lorenzo, Maria Teresa & Brysting, Anne Krag (2016). Polyploid and ecological adaptation in Cochlearia L. (Brassicaceae) in Northern Norway. Full text in Research Archive
Brysting, Anne Krag (2016). Blomstene og biene - historier om koevolusjon. Full text in Research Archive
Birkeland, Siri; Gustafsson, A Lovisa S; Brysting, Anne Krag; Slotte, Tanja; Brochmann, Christian & Nowak, Michael (2016). Testing for convergent evolution of cold tolerance in Arctic plants. Full text in Research Archive
Evankow, Ann; Fredriksen, Stein; Christie, Hartvig C; Junge, Claudia & Brysting, Anne Krag (2015). Genetic tools reveal diversity and structure of kelp forests in Norway. Full text in Research Archive
Haug, Solveig; Karbassioon, Arrian; Brysting, Anne Krag & Nielsen, Anders (2015). Pollinator interactions with wild raspberry and the surrounding plant community along an altitudinal gradient. Full text in Research Archive
Evankov, Ann Marie; Fredriksen, Stein; Christie, H.; Junge, Claudia & Brysting, Anne Krag (2015). Population genetic diversity and structure of two kelp species (Laminariales) in Norway. Full text in Research Archive
Grundt, Hanne H.; Brysting, Anne Krag & Elven, Reidar (2015). Storlind Tilia platyphyllos i Østfold og Norge: Rød eller svart? Blyttia : Norsk botanisk forenings tidsskrift. ISSN 0006-5269. 73, p. 13–22. Full text in Research Archive
Brysting, Anne Krag (2015). Polyploiditet: Hva skjer når planter fordobler kromosomtallet sitt? Full text in Research Archive
Brandrud, Marie Kristine; Paun, Ovidiu; Nordal, Inger & Brysting, Anne Krag (2015). Polyploidy and ecological adaptation in Cochlearia in Northern Norway. Full text in Research Archive
Jørgensen, Marte Holten & Brysting, Anne Krag (2014). Er livet et tre? Biolog. ISSN 0801-0722. 2014(2), p. 8–13. Full text in Research Archive
Svoen, Mildrid Elvik & Brysting, Anne Krag (2014). Population dynamics of Silene acaulis in the High Arctic. Full text in Research Archive
Olsen, Luka Natassja & Brysting, Anne Krag (2014). Icelandic Cochlearia (Scurvygrasses) – arctic or European, or both? Full text in Research Archive
Brandrud, Marie Kristine; Paun, Ovidiu & Brysting, Anne Krag (2014). Polyploidy and ecotype variation in Cochlearia officinalis L. and related species. Full text in Research Archive
Brysting, Anne Krag (2014). Polyploidy stories from the Arctic and North Atlantic region. Full text in Research Archive
Brysting, Anne Krag (2014). Polyploiditet: Hva skjer når planter fordobler kromosomtallet sitt? Full text in Research Archive
Brandrud, Marie Kristine; Nordal, Inger; Paun, Ovidiu; Lorenzo, Maite; Bjorå, Charlotte Sletten & Stabbetorp, Odd Egil [Show all 7 contributors for this article] (2014). Polyploid and ecotype variation in the Cochlearia officinalis complex. Full text in Research Archive
Brysting, Anne Krag (2013). Polyploidy and self-incompatibility in Arabidopsis and other polyploidy stories. Full text in Research Archive
Brysting, Anne Krag (2013). Müntzings klassiske lærebok-eksempel: allotetraploid Galeopsis tetrahit. Full text in Research Archive
Brysting, Anne Krag (2013). Polyploiditet: Hva skjer når planter fordobler kromosomtallet sitt? Hvordan bidrar polyploiditet til artskunnskapen vår? Har vi plutselig mange flere arter enn vi trodde? Full text in Research Archive
Brysting, Anne Krag & Jørgensen, Marte Holten (2013). Livets tre tegnes på nytt. DNA-analyser gir kunnskap omslektskapet mellom levende organismer. Genialt. ISSN 0804-225X. 3-2013, p. 10–13. Full text in Research Archive
Brysting, Anne Krag (2013). Cochlearia officinalis in Norway. Report on the work carried out using the SRF fund. Newsletter of the Systematics Association. ISSN 1744-5701. 35, p. 13–14. Full text in Research Archive
Brysting, Anne Krag (2013). Livets tre i lys av molekylære metoder. Full text in Research Archive
Branderud, Marie K. & Brysting, Anne Krag (2013). Polyploidy and ecotype variation in the Cochlearia officinalis complex. Full text in Research Archive
Nitter, Eivind L. & Brysting, Anne Krag (2013). Effects of sheep grazing on bumblebee abundance in an alpine ecosystem. Full text in Research Archive
Botnen, Synnøve Smebye; Kauserud, Håvard; Davey, Marie Louise; Brysting, Anne Krag & Eidesen, Pernille Bronken (2020). Biodiversity in the dark: root-associated fungi in the Arctic. Universitetet i Oslo. Full text in Research Archive Show summary
In her PhD thesis, Synnøve Smebye Botnen investigated the diversity and community ecology of Arctic fungi, from beforehand a poorly studied group of organisms. Climate change will have major impacts on Arctic ecosystems and in this regard, we need baseline information about the existing and putatively unique arctic biodiversity. As elsewhere, arctic plants live in symbiosis with various root-associated fungi that e.g. feed the host plants with essential nutrients. To assess the diversity of these fungi in the arctic, and which environmental factors influence them, Botnen used a technique called DNA-metabarcoding, relying on modern high-throughput DNA sequencing methods. Her main study area was Svalbard. The DNA-based methods revealed an extensive diversity of root-associated fungi in the arctic, where the majority still are lacking scientific names. To illustrate, a single plant root system at Svalbard may host as many fungi as the number of plant species at entire Svalbard. Only a minor proportion of these fungi produce macroscopically aboveground fruit bodies. Botnen revealed that climate conditions have a significant effect on the distribution of arctic fungi, as well as other environmental factors. This means that the ongoing climate change will re-distribute the fungal diversity. Not only the physical environment shapes the fungal communities; Botnen revealed that some types of root-associated fungi can be highly host specific. However, when it comes to ectomycorrhizal fungi – one specific group of root-associated fungi – Botnen revealed that they typically colonize different host plants and show little host specificity. In addition to empirical studies, Botnen also conducted a method study, where specific elements of the DNA-metabarcoding approach was evaluated. These analyses revealed that the DNA-metabarcoding method provides a very robust framework to study changes in communities of fungi and microorganisms. Taken together, results from the thesis provides baseline information about the extensive diversity of arctic fungi. This baseline information is much needed to better understand the expected changes in arctic ecosystems. However, most of all, the thesis illustrates that we barely have scraped the surface of this largely unknown fungal diversity, calling for intensified research efforts on this topic.
Hansen, Simen Hyll; Kauserud, Håvard; Davey, Marie Louise; Thoen, Ella; Vik, Unni & Brysting, Anne Krag (2018). Climate and host identity structure fungal endophyte communities. Universitetet i Oslo. Full text in Research Archive
Aas, Anders Bjørnsgaard; Davey, Marie Louise; Kauserud, Håvard; Easterday, William Ryan & Brysting, Anne Krag (2017). Root-associated microbes: Spatial Oddities and Methodological Perspectives. Universitetet i Oslo. Full text in Research Archive

View all works in NVA

Published May 26, 2011 9:46 PM - Last modified Oct. 25, 2021 1:08 PM

Projects

Research groups

Centre for Computational Inference in Evolutionary Life Science (CELS)