24 results on '"Christoph Scheidegger"'
Search Results
2. Gene flow in a pioneer plant metapopulation (Myricaria germanica) at the catchment scale in a fragmented alpine river system
- Author
-
Sabine Fink, Andrea Hoppler-Wiedmer, Veronika Zengerer, Gregory Egger, Martin Schletterer, and Christoph Scheidegger
- Subjects
Medicine ,Science - Abstract
Abstract River alterations for natural hazard mitigation and land reclamation result in habitat decline and fragmentation for riparian plant species. Extreme events such as floods are responsible for additional local species loss or population decline. Tributaries might provide refugia and subsequent source populations for the colonization of downstream sites in connected riverine networks with metapopulations of plant species. In this study, we analyzed the metapopulation structure of the endangered riparian shrub species Myricaria germanica along the river Isel, Austria, which is part of the Natura 2000 network, and its tributaries. The use of 22 microsatellite markers allowed us to assess the role of tributaries and single populations as well as gene flow up- and downstream. The analysis of 1307 individuals from 45 sites shows the influence of tributaries to the genetic diversity at Isel and no overall isolation by distance pattern. Ongoing bidirectional gene flow is revealed by the detection of first-generation migrants in populations of all tributaries as well as the river Isel, supporting upstream dispersal by wind (seeds) or animals (seeds and pollen). However, some populations display significant population declines and high inbreeding, and recent migration rates are non-significant or low. The genetic pattern at the mouth of river Schwarzach into Isel and shortly thereafter river Kalserbach supports the finding that geographically close populations remain connected and that tributaries can form important refugia for M. germanica in the dynamic riverine network. Conservation and mitigation measures should therefore focus on providing sufficient habitat along tributaries of various size allowing pioneer plants to cope with extreme events in the main channel, especially as they are expected to be more frequent under changing climate.
- Published
- 2022
- Full Text
- View/download PDF
3. Cyanobacteria: Extreme Environments and Toxic Metabolites
- Author
-
Francesca Pittino, Juliana Oliveira, Mariana De Almeida Torres, Sabine Fink, Elisabeth M. L. Janssen, and Christoph Scheidegger
- Subjects
Cyanobacteria ,Cyanotoxins ,Water quality ,Bioaccumulation ,Lichen ,Chemistry ,QD1-999 - Abstract
Cyanobacteria, also known as blue-green algae, are photosynthetic bacteria that can colonize different habitats, including extreme ones. They are of great interest to the scientific community, especially because of their ability to produce cyanotoxins: toxic secondary metabolites potentially harmful to organisms especially when released to surface waters.
- Published
- 2022
- Full Text
- View/download PDF
4. Deep divergence between island populations in lichenized fungi
- Author
-
Silke Werth, Peter Meidl, and Christoph Scheidegger
- Subjects
Medicine ,Science - Abstract
Abstract Macaronesia is characterized by a high degree of endemism and represents a noteworthy system to study the evolutionary history of populations and species. Here, we compare the population-genetic structure in three lichen-forming fungi, the widespread Lobaria pulmonaria and two Macaronesian endemics, L. immixta and L. macaronesica, based on microsatellites. We utilize population genetic approaches to explore population subdivision and evolutionary history of these taxa on the Canary Islands, Madeira, Azores, and the western Iberian Peninsula. A common feature in all species was the deep divergence between populations on the Azores, a pattern expected by the large geographic distance among islands. For both endemic species, there was a major split between archipelagos. In contrast, in the widespread L. pulmonaria, divergent individuals were distributed across multiple archipelagos, suggesting a complex evolutionary history involving repeated migration between islands and mainland.
- Published
- 2021
- Full Text
- View/download PDF
5. Gene flow in a highly dynamic habitat and a single founder event: Proof from a plant population on a relocated river site
- Author
-
Romy Woellner, Christoph Scheidegger, and Sabine Fink
- Subjects
Metapopulation ,Demography ,Colonization ,Floodplain ,Myricaria germanica ,Genetic diversity ,Ecology ,QH540-549.5 - Abstract
River relocations due to realization of infrastructure projects or flood protection provide a high potential for ecological restorations and the creation of near-natural habitats. Colonization success of new riparian habitats in the dynamic riverine zone is rarely predictable, as the survival of sessile plants is highly dependent on flood events. Relocated rivers offer a unique opportunity to study restoration success, and using genetic information allows tracing to source populations and assessing connectivity. This study focuses on the colonization of a new, 3.4 km long river stretch in the Inn catchment (Switzerland), with an artificial, stable shoreline and a dynamic riverine zone with gravel bars. We assess the colonization success of Myricaria germanica, a flagship species for floodplain pioneer vegetation, 14 years after river relocation. The population with over 600 individuals of which 147 were used for genetic analysis based on 22 microsatellite markers in comparison to 11 potential source populations up- and downstream of the new site. Our results on demography and genetic composition together with information on flood events allow tracing the origin of the subpopulation along the stable shoreline to a single founder event but several founder individuals further upstream. The subpopulation in the dynamic zone is younger and more likely strongly dependent on gene flow from the stable shoreline subpopulation, but allows for rejuvenation at the site. Genetic patterns along the catchment indicate ongoing gene flow, suggesting potential for colonization success for further restorations in the catchment. Our data reveals that near-natural flood dynamics with repeated larger flood events is a key factor for successful colonization of dynamic riparian habitats.
- Published
- 2021
- Full Text
- View/download PDF
6. Microsatellite based genetic diversity of the widespread epiphytic lichen Usnea subfloridana (Parmeliaceae, Ascomycota) in Estonia: comparison of populations from the mainland and an island
- Author
-
Polina Degtjarenko, Inga Jüriado, Tiina Mandel, Tiiu Tõrra, Andres Saag, Christoph Scheidegger, and Tiina Randlane
- Subjects
Botany ,QK1-989 - Abstract
Understanding the distribution of genetic patterns and structure is an essential target in population genetics and, thereby, important for conservation genetics. The main aim of our study was to investigate the population genetics of Usnea subfloridana, a widespread lichenised fungus, focusing on a comparison of genetic variation of its populations amongst three geographically remote and disconnected regions, in order to determine relationships amongst environmental data, variation in lichen secondary chemistry and microsatellite data in genotyped populations. In all, 928 Usnea thalli from 17 populations were genotyped using seven specific fungal microsatellite markers. Different measures of genetic diversity (allelic richness, private allelic richness, Nei’s unbiased genetic diversity and clonal diversity) were calculated and compared between lichen populations. Our results revealed a low genetic differentiation of U. subfloridana populations amongst three distant areas in Estonia and also a high level of gene flow. The results support suggestion of the long-range vegetative dispersal of subpendulous U. subfloridana via symbiotic propagules (soralia, isidia or fragments of thalli). Our study has also provided evidence that environmental variables, including mean annual temperature and geographical longitude, shape the genetic structure of U. subfloridana populations in Estonia. Additionally, a weak but statistically significant correlation between lichen chemotypes and microsatellite allele distribution was found in genotyped specimens.
- Published
- 2019
- Full Text
- View/download PDF
7. New species and records of Pyxine (Caliciaceae) in China
- Author
-
Mei-Xia Yang, Xin-Yu Wang, Dong Liu, Yan-Yun Zhang, Li-Juan Li, An-Cheng Yin, Christoph Scheidegger, and Li-Song Wang
- Subjects
Botany ,QK1-989 - Abstract
In this study, the diversity of Pyxine Fr. in China was assessed based on morphological and chemical traits and molecular data are inferred from ITS and mtSSU sequences. Nineteen species were recognised, including three that are new to science (i.e. P. flavicans M. X. Yang & Li S. Wang, P. hengduanensis M. X. Yang & Li S. Wang and P. yunnanensis M. X. Yang & Li S. Wang) and three records new to China were found (i.e. P. cognata Stirt., P. himalayensis Awas. and P. minuta Vain.). Pyxine yunnanensis is diagnosed by the small size of the apothecia, a white medulla of the stipe and the presence of lichexanthone. Pyxine flavicans is characterised by broad lobes, a pale yellow medulla of the stipe and the presence of atranorin. Pyxine hengduanensis can be distinguished by its pale yellow medulla, marginal labriform soralia and the absence of atranorin. Detailed descriptions of each new species are presented, along with a key to the known species of Pyxine in China.
- Published
- 2019
- Full Text
- View/download PDF
8. From natural forest to cultivated land: Lichen species diversity along land-use gradients in Kanchenjunga, Eastern Nepal
- Author
-
Til Bikram Chongbang, Christine Keller, Michael Nobis, Christoph Scheidegger, and Chitra Bahadur Baniya
- Subjects
Environmental sciences ,GE1-350 ,Geography (General) ,G1-922 - Published
- 2018
- Full Text
- View/download PDF
9. Ethnolichenology—The Use of Lichens in the Himalayas and Southwestern Parts of China
- Author
-
Mei-Xia Yang, Shiva Devkota, Li-Song Wang, and Christoph Scheidegger
- Subjects
lichen ,ethnic use ,medicinal ,edible species ,Himalayas ,southwestern China ,Biology (General) ,QH301-705.5 - Abstract
Lichens are used in traditional medicine, food and various other ethnic uses by cultures across the Himalayas and southwestern parts of China. Evidence-based knowledge from historical and modern literatures and investigation of ethnic uses from 1990 proved that lichen species used as medicine in the Himalayas and southwestern parts of China totaled to 142 species; furthermore, 42 species were utilized as food. Moreover, some lichens are popularly used for lichen produce in ethnic and modern life. An understanding and clarification of the use of lichens in the Himalayas and southeastern parts of China can therefore be important for understanding uses of lichens elsewhere and a reference for additional research of lichen uses in the future.
- Published
- 2021
- Full Text
- View/download PDF
10. Rethinking Pumped Storage Hydropower in the European Alps: A Call for New Integrated Assessment Tools to Support the Energy Transition
- Author
-
Astrid Björnsen Gurung, Axel Borsdorf, Leopold Füreder, Felix Kienast, Peter Matt, Christoph Scheidegger, Lukas Schmocker, Massimiliano Zappa, and Kathrin Volkart
- Subjects
Austria ,energy transition ,Alps ,environmental impacts ,pumped storage hydropower ,sustainability assessment ,Switzerland ,Environmental sciences ,GE1-350 - Abstract
The European Alps are well positioned to contribute significantly to the energy transition. In addition to sites with above-average potential for wind and solar power, the “water towers” of Europe provide flexible, low-carbon power generation as well as energy storage. In the future, hydropower systems are expected to become more than mere electricity generators, serving a key role as flexible complements to intermittent power generators and as providers of large-scale seasonal and daily energy storage. Energy transition on national and European scales can be facilitated by expanding the capacity of pumped storage hydropower (PSHP) plants. Yet the extension of hydropower production, in particular PSHP, remains controversial, primarily due to environmental concerns. Focusing on 2 Alpine countries, Austria and Switzerland, this paper provides a system view of hydropower production and energy storage in the Alps. It discusses advantages and drawbacks of various assessment tools and identifies gaps and needs for the integrated assessment of PSHP plants. It concludes that instruments that evaluate the impacts and sustainability of PSHP projects need to be developed, elaborated, and applied in a participatory manner, in order to promote public dialogue, increase social acceptance, and, ideally, encourage energy consumers to become advocates of a sustainable energy future.
- Published
- 2016
- Full Text
- View/download PDF
11. Epiphytes in wooded pastures: Isolation matters for lichen but not for bryophyte species richness.
- Author
-
Thomas Kiebacher, Christine Keller, Christoph Scheidegger, and Ariel Bergamini
- Subjects
Medicine ,Science - Abstract
Sylvo-pastoral systems are species-rich man-made landscapes that are currently often severely threatened by abandonment or management intensification. At low tree densities, single trees in these systems represent habitat islands for epiphytic cryptogams. Here, we focused on sycamore maple (Acer pseudoplatanus) wooded pastures in the northern European Alps. We assessed per tree species richness of bryophytes and lichens on 90 sycamore maple trees distributed across six study sites. We analysed the effects of a range of explanatory variables (tree characteristics, environmental variables and isolation measures) on the richness of epiphytic bryophytes and lichens and various functional subgroups (based on diaspore size, habitat preference and red list status). Furthermore, we estimated the effect of these variables on the occurrence of two specific bryophyte species (Tayloria rudolphiana, Orthotrichum rogeri) and one lichen species (Lobaria pulmonaria) of major conservation concern. Bryophytes and lichens, as well as their subgroups, were differently and sometimes contrastingly affected by the variables considered: tree diameter at breast height had no significant effect on bryophytes but negatively affected many lichen groups; tree phenological age positively affected red-listed lichens but not red-listed bryophytes; increasing isolation from neighbouring trees negatively affected lichens but not bryophytes. However, the high-priority bryophyte species T. rudolphiana was also negatively affected by increased isolation at small spatial scales. Orthotrichum rogeri was more frequent on young trees and L. pulmonaria was more frequent on trees with thin stems and large crowns. The results indicate that local dispersal is important for lichens, whereas long distance dispersal seems to be more important for colonisation by bryophytes. Furthermore, our study highlights that different conservation measures need to be taken depending on the taxonomic and functional species group or the individual species that is addressed. In practice, for the conservation of a high overall richness in sylvo-pastoral systems, it is crucial to sustain not only old and large trees but rather a wide range of tree sizes and ages.
- Published
- 2017
- Full Text
- View/download PDF
12. Seasonal Changes in Bird Species and Feeding Guilds along Elevational Gradients of the Central Himalayas, Nepal.
- Author
-
Hem Bahadur Katuwal, Khadga Basnet, Bhaiya Khanal, Shiva Devkota, Sanjeev Kumar Rai, Jyoti Prasad Gajurel, Christoph Scheidegger, and Michael P Nobis
- Subjects
Medicine ,Science - Abstract
The Himalayas are a global hotspot for bird diversity with a large number of threatened species, but little is known about seasonal changes in bird communities along elevational gradients in this region. We studied the seasonality of bird diversity in six valleys of the Central Himalayas, Nepal. Using 318 plots with a 50 m radius, located from 2200 to 3800 m a.s.l., and repeated sampling during different seasons (mainly pre-monsoon, monsoon, and post-monsoon), we analyzed 3642 occurrences of 178 species. Birds classified in the literature as resident were more species-rich than migratory birds (140 vs. 38 species). In all six valleys and within the studied elevation range, species richness of all birds showed a peak at mid-elevation levels of 2600 or 3000 m a.s.l. Similar patterns were found for the most species-rich feeding guilds of insectivores (96 species) and omnivores (24 species), whereas the species richness of herbivores (37 species including frugivores) increased towards higher elevations. Among these feeding guilds, only species richness of insectivores showed pronounced seasonal changes with higher species numbers during post-monsoon season. Similarly, individual bird species showed distinct spatio-temporal distribution patterns, with transitions from species dominated by elevational differences to those characterized by strong seasonal changes. In an era of climate change, the results demonstrate that individual bird species as well as feeding guilds might greatly differ in their responses to climate warming and changes in the seasonality of the precipitation regime, two aspects of climate change which should not be analyzed independently.
- Published
- 2016
- Full Text
- View/download PDF
13. Congruent Genetic Structure in the Lichen-Forming Fungus Lobaria pulmonaria and Its Green-Algal Photobiont
- Author
-
Silke Werth and Christoph Scheidegger
- Subjects
Microbiology ,QR1-502 ,Botany ,QK1-989 - Abstract
The extent of codispersal of symbionts is one of the key factors shaping genetic structures of symbiotic organisms. Concordant patterns of genetic structure are expected in vertically transmitted symbioses, whereas horizontal transmission generally uncouples genetic structures unless the partners are coadapted. Here, we compared the genetic structures of mutualists, the lichen-forming fungus Lobaria pulmonaria and its primary green-algal photobiont, Dictyochloropsis reticulata. We performed analysis of molecular variance and variogram analysis to compare genetic structures between symbiosis partners. We simulated the expected number of multilocus-genotype recurrences to reveal whether the distribution of multilocus genotypes of either species was concordant with panmixia. Simulations and tests of linkage disequilibrium provided compelling evidence for the codispersal of mutualists. To test whether genotype associations between symbionts were consistent with randomness, as expected under horizontal transmission, we simulated the recurrence of fungal-algal multilocus genotype associations expected by chance. Our data showed nonrandom associations of fungal and algal genotypes. Either vertical transmission or horizontal transmission coupled with coadaptation between symbiont genotypes may have created these nonrandom associations. This study is among the first to show codispersal and highly congruent genetic structures in the partners of a lichen mutualism.
- Published
- 2012
- Full Text
- View/download PDF
14. Genomic DNA Extraction and Genotyping of Dictyochloropsis Green Algae Strains
- Author
-
Francesco Dal Grande, Carolina Cornejo, Christoph Scheidegger, and Andreas Beck
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Dictyochloropsis is an ecologically important genus of free-living and symbiotic green algae. Representatives of this genus are horizontally transmitted among several fungi of the family Lobariaceae, thus forming photobiont-mediated guilds. This protocol is suitable for extracting DNA from algal cultures and lichen samples and for genotyping seven unlinked Dictyochloropsis reticulata microsatellite markers in a single PCR multiplex.Figure 1. Schematic representation of the analysis pipeline
- Published
- 2015
- Full Text
- View/download PDF
15. Axenic Cultivation of Mycelium of the Lichenized Fungus, Lobaria pulmonaria (Peltigerales, Ascomycota)
- Author
-
Carolina Cornejo, Christoph Scheidegger, and Rosmarie Honegger
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Lichens are symbiotic organisms consisting of a fungal partner (the mycobiont) and one or more algal or cyanobacterial partners (the photobiont); moreover lichen thalli comprise a plethora of epi- and endobiotic bacteria and non-lichenized fungi. Genetic markers are the most promising tools for the study of fungal diversity. However, applying genetic methods to intimately admixed symbiotic organisms typically requires the development of species-specific genetic markers, since DNA extraction from environmental specimens implicates the acquirement of total DNA of all symbionts and their cohabitants. While the cultivation of the alga is straight forward, the axenic cultivation of lichen-forming fungi is more difficult due to their very slow growth, as compared with the majority of non-lichenized taxa, and the presence of saprophytic, endophytic and parasitic fungi within the lichen thallus. Moreover, lichen-forming fungi (predominantly ascomycetes, few basidiomycetes) are oligotrophic organisms and thus adapted to nutrient poor conditions; in axenic culture on nutrient-rich media, as normally used for mass production of fast-growing saprophytic fungi, they often autointoxicate. Most lichen-forming fungi are not obligately biotrophic and thus can be cultured in the non-symbiotic state. Here, we present a protocol for the isolation of the lichen-forming ascomycete Lobaria pulmonaria into axenic culture and for mycelial mass culture as a source of pure fungal DNA. We describe the initiation of axenic cultures on agar plates from germinating ascospores and explain the optimization of the in vitro growth in liquid medium. By grinding the few dense, only centrifugally growing fungal colonies with a homogenizer we obtain lots of smaller, well growing colonies and thus higher amounts of mycelium for DNA or RNA isolation (Honegger and Bartnicki-Garcia, 1991).
- Published
- 2015
- Full Text
- View/download PDF
16. Effects of Management on Lichen Species Richness, Ecological Traits and Community Structure in the Rodnei Mountains National Park (Romania).
- Author
-
Ioana Violeta Ardelean, Christine Keller, and Christoph Scheidegger
- Subjects
Medicine ,Science - Abstract
Lichens are valuable bio-indicators for evaluating the consequences of human activities that are increasingly changing the earth's ecosystems. Since a major objective of national parks is the preservation of biodiversity, our aim is to analyse how natural resource management, the availability of lichen substrates and environmental parameters influence lichen diversity in Rodnei Mountains National Park situated in the Eastern Carpathians. Three main types of managed vegetation were investigated: the transhumance systems in alpine meadows, timber exploitation in mixed and pure spruce forests, and the corresponding conserved sites. The data were sampled following a replicated design. For the analysis, we considered not only all lichen species, but also species groups from different substrates such as soil, trees and deadwood. The lichen diversity was described according to species richness, red-list status and substrate-specialist species richness. The variation in species composition was related to the environmental variables. Habitat management was found to negatively influence species richness and alter the lichen community composition, particularly for threatened and substrate-specialist species. It reduced the mean level of threatened species richness by 59%, when all lichen species were considered, and by 81%, when only epiphytic lichens were considered. Management-induced disturbance significantly decreased lichen species richness in forest landscapes with long stand continuity. The diversity patterns of the lichens indicate a loss of species richness and change in species composition in areas where natural resources are still exploited inside the borders of the national park. It is thus imperative for protected areas, in particular old-growth forests and alpine meadows, to receive more protection than they have received in the past to ensure populations of the characteristic species remain viable in the future.
- Published
- 2015
- Full Text
- View/download PDF
17. Gene flow within and between catchments in the threatened riparian plant Myricaria germanica.
- Author
-
Silke Werth and Christoph Scheidegger
- Subjects
Medicine ,Science - Abstract
One of the major distinctions of riparian habitats is their linearity. In linear habitats, gene flow is predicted to follow a one-dimensional stepping stone model, characterized by bidirectional gene flow between neighboring populations. Here, we studied the genetic structure of Myricaria germanica, a threatened riparian shrub which is capable of both wind and water dispersal. Our data led us to reject the 'one catchment-one gene pool' hypothesis as we found support for two gene pools, rather than four as expected in a study area including four catchments. This result also implies that in the history of the studied populations, dispersal across catchments has occurred. Two contemporary catchment-crossing migration events were detected, albeit between spatially proximate catchments. Allelic richness and inbreeding coefficients differed substantially between gene pools. There was significant isolation by distance, and our data confirmed the one-dimensional stepping-stone model of gene flow. Contemporary migration was bidirectional within the studied catchments, implying that dispersal vectors other than water are important for M. germanica.
- Published
- 2014
- Full Text
- View/download PDF
18. Genetic basis of self-incompatibility in the lichen-forming fungus Lobaria pulmonaria and skewed frequency distribution of mating-type idiomorphs: implications for conservation.
- Author
-
Garima Singh, Francesco Dal Grande, Carolina Cornejo, Imke Schmitt, and Christoph Scheidegger
- Subjects
Medicine ,Science - Abstract
Fungal populations that reproduce sexually are likely to be genetically more diverse and have a higher adaptive potential than asexually reproducing populations. Mating systems of fungal species can be self-incompatible, requiring the presence of isolates of different mating-type genes for sexual reproduction to occur, or self-compatible, requiring only one. Understanding the distribution of mating-type genes in populations can help to assess the potential of self-incompatible species to reproduce sexually. In the locally threatened epiphytic lichen-forming fungus Lobaria pulmonaria (L.) Hoffm., low frequency of sexual reproduction is likely to limit the potential of populations to adapt to changing environmental conditions. Our study provides direct evidence of self-incompatibility (heterothallism) in L. pulmonaria. It can thus be hypothesized that sexual reproduction in small populations might be limited by an unbalanced distribution of mating-type genes. We therefore assessed neutral genetic diversity (using microsatellites) and mating-type ratio in 27 lichen populations (933 individuals). We found significant differences in the frequency of the two mating types in 13 populations, indicating a lower likelihood of sexual reproduction in these populations. This suggests that conservation translocation activities aiming at maximizing genetic heterogeneity in threatened and declining populations should take into account not only presence of fruiting bodies in transplanted individuals, but also the identity and balanced representation of mating-type genes.
- Published
- 2012
- Full Text
- View/download PDF
19. Characterization of Microsatellite Loci in Lichen-Forming Fungi of Bryoria Section Implexae (Parmeliaceae)
- Author
-
Olga Nadyeina, Carolina Cornejo, Carlos G. Boluda, Leena Myllys, Víctor J. Rico, Ana Crespo, and Christoph Scheidegger
- Subjects
Ascomycetes ,Bryoria implexa ,lichen-forming fungi ,microsatellites ,Trebouxia spp ,Biology (General) ,QH301-705.5 ,Botany ,QK1-989 - Abstract
Premise of the study: The locally rare, haploid, lichen-forming fungi Bryoria capillaris, B. fuscescens, and B. implexa are associated with boreal forests and belong to Bryoria sect. Implexae. Recent phylogenetic studies consider them to be conspecific. Microsatellite loci were developed to study population structure in Bryoria sect. Implexae and its response to ecosystem disturbances. Methods and Results: We developed 18 polymorphic microsatellite markers using 454 pyrosequencing data assessed in 82 individuals. The number of alleles per locus ranged from two to 13 with an average of 4.6. Nei's unbiased gene diversity, averaged over loci, ranged from 0.38 to 0.52. The markers amplified with all three species, except for markers Bi05, Bi15, and Bi18. Conclusions: The new markers will allow the study of population subdivision, levels of gene introgression, and levels of clonal spread of Bryoria sect. Implexae. They will also facilitate an understanding of the effects of forest disturbance on genetic diversity of these lichen species.
- Published
- 2014
- Full Text
- View/download PDF
20. Characterization of Fungus-Specific Microsatellite Markers in the Lichen Fungus Usnea subfloridana (Parmeliaceae)
- Author
-
Tiiu Tõrra, Carolina Cornejo, Saran Cheenacharoen, Francesco Dal Grande, Liis Marmor, and Christoph Scheidegger
- Subjects
Ascomycetes ,lichen-forming fungi ,microsatellites ,population subdivision ,Usnea florida ,Usnea subfloridana ,Biology (General) ,QH301-705.5 ,Botany ,QK1-989 - Abstract
Premise of the study: Microsatellite loci were developed for the haploid lichenized fungal species Usnea subfloridana to study its population subdivision and the species' response to forest disturbance, fragmentation, and environmental pollution. Methods and Results: We developed 14 polymorphic microsatellite markers using 454 pyrosequencing data of U. subfloridana. The number of alleles per locus ranged from three to 15, and Nei's unbiased gene diversity averaged over nine markers without null alleles ranged from 0.64 to 0.67. Evaluation of the cross-species amplification in U. glabrescens and U. wasmuthii indicates that these markers are also informative in other Usnea species. Conclusions: These markers will allow us to investigate the effects of forest management and environmental pollution on genetic population structure of U. subfloridana and closely related species. Moreover, they will help facilitate phylogeographic studies of U. subfloridana across the species' distribution area in Europe.
- Published
- 2014
- Full Text
- View/download PDF
21. Characterization of Microsatellite Loci in the Himalayan Lichen Fungus Lobaria pindarensis (Lobariaceae)
- Author
-
Shiva Devkota, Carolina Cornejo, Silke Werth, Ram Prasad Chaudhary, and Christoph Scheidegger
- Subjects
Ascomycetes ,Himalayas ,lichen-forming fungi ,Lobaria pindarensis ,microsatellites ,population subdivision ,Biology (General) ,QH301-705.5 ,Botany ,QK1-989 - Abstract
Premise of the study: Microsatellite loci were developed for the rare, Himalayan, endemic haploid lichen fungus, Lobaria pindarensis, to study its population subdivision and the species' response to forest disturbance and fragmentation. Methods and Results: We developed 18 polymorphic microsatellite markers using 454 pyrosequencing data and assessed them in 109 individuals. The number of alleles per locus ranged from three to 11 with an average of 6.9. Nei's unbiased gene diversity, averaged over loci, ranged from 0.514 to 0.685 in the three populations studied. The cross-amplification success with related species (L. chinensis, L. gyrophorica, L. isidiophora, L. orientalis, L. pulmonaria, L. spathulata, and Lobaria sp.) was generally high and decreased with decreasing relationship to L. pindarensis. Conclusions: The new markers will allow the study of genetic diversity and differentiation within L. pindarensis across its distribution. Moreover, they will enable us to study the effects of forest management on the genetic population structure of this tree-colonizing lichen and to carry out population genetic studies of related species in East Asia.
- Published
- 2014
- Full Text
- View/download PDF
22. Development and Characterization of Microsatellite Loci in the Endangered Species Taxus wallichiana (Taxaceae)
- Author
-
Jyoti Prasad Gajurel, Carolina Cornejo, Silke Werth, Krishna Kumar Shrestha, and Christoph Scheidegger
- Subjects
454 pyrosequencing ,conservation genetics ,Himalayan yew ,Himalayas ,simple sequence repeat marker ,Biology (General) ,QH301-705.5 ,Botany ,QK1-989 - Abstract
Premise of the study: Microsatellite primers were developed in the endangered tree species Taxus wallichiana from Nepal to investigate regional genetic differentiation, local genetic diversity, and gene flow for the conservation of this species under climate- and land-use change scenarios in mountain regions of Nepal. Methods and Results: We developed 10 highly polymorphic microsatellite markers from 454 DNA sequencing. Characterization of the new microsatellite loci was done in 99 individuals collected from three valleys with different climatic regimes. The number of alleles per locus varied from four to 12. Observed heterozygosity of populations, averaged across loci, ranged from 0.30 to 0.59. Conclusions: The new markers provided by this study will substantially increase the resolution for detailed studies in phylogeography, population genetics, and parentage analysis.
- Published
- 2013
- Full Text
- View/download PDF
23. Characterization of Microsatellite Loci in the Lichen Fungus Lobaria pulmonaria (Lobariaceae)
- Author
-
Silke Werth, Carolina Cornejo, and Christoph Scheidegger
- Subjects
Ascomycetes ,Ascomycota ,lichen fungi ,Lobaria pulmonaria ,microsatellites ,population subdivision ,Biology (General) ,QH301-705.5 ,Botany ,QK1-989 - Abstract
Premise of the study: Microsatellite loci were developed for the threatened haploid lichen fungus Lobaria pulmonaria to increase the resolution to identify clonal individuals, and to study its population subdivision. Methods and Results: We developed 14 microsatellite markers from 454 DNA sequencing data of L. pulmonaria and tested for cross-amplification with L. immixta and L. macaronesica. The number of alleles per locus ranged from two to 23. Nei's unbiased gene diversity, averaged over loci, ranged from 0.434 to 0.517 in the three studied populations. Conclusions: The new markers will increase the genetic resolution in studies that aim at disentangling clones in L. pulmonaria and may be useful for closely related species within Lobaria sect. Lobaria.
- Published
- 2013
- Full Text
- View/download PDF
24. Prediction of lichen diversity in an UNESCO biosphere reserve â correlation of high resolution remote sensing data with field samples.
- Author
-
Lars Waser, Meinrad Kuechler, Markus Schwarz, Eva Ivits, Silvia Stofer, and Christoph Scheidegger
- Subjects
LICHENS ,BIOSPHERE reserves ,LAND use - Abstract
Abstract  The present study focuses on developing models to predict lichen species richness in a UNESCO Biosphere Reserve of the Swiss Pre-Alps following a gradient of land-use intensity combining remote sensing data and regression models. The predictive power of the models and the obtained r ranging from 0.5 for lichens on soil to 0.8 for lichens on trees can be regarded as satisfactory to good, respectively. The study revealed that a combination of airborne and spaceborne remote sensing data produced a variety of ecological meaningful variables. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.