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A Gross - One of the best experts on this subject based on the ideXlab platform.
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virulence of hymenoscyphus albidus and native and introduced hymenoscyphus fraxineus on Fraxinus excelsior and Fraxinus pennsylvanica
Plant Pathology, 2016Co-Authors: A Gross, Thomas N SieberAbstract:Ash dieback is caused by Hymenoscyphus fraxineus, a cryptic species of the putatively harmless Hymenoscyphus albidus. Recently, H. fraxineus was found to be native to East Asia. However, the virulence of Asian H. fraxineus strains on Fraxinus excelsior and the virulence of European H. albidus on hosts other than F. excelsior and Fraxinus mandshurica have not yet been assessed. In a wound inoculation study, the virulence of four H. albidus and four European and Japanese H. fraxineus strains was assessed on F. excelsior and Fraxinus pennsylvanica in a climate chamber. Lesion lengths were measured after approximately three and a half months. No lesions were observed on the negative control or on trees inoculated with H. albidus. In contrast, inoculation with H. fraxineus induced typical symptoms of ash dieback on both tree species. Japanese H. fraxineus strains induced significantly longer lesions compared to European strains. Fraxinus excelsior was highly susceptible and developed lesions averaging lengths of 1·7 and 8·4 cm for European and Japanese strains, respectively. Fraxinus pennsylvanica was less susceptible and developed average lesion lengths of 1·6 and 4·8 cm for European and Japanese strains, respectively. Most strains were successfully reisolated from necrotic lesions or inocula, fulfilling Koch's postulates. The data show that additional introductions of H. fraxineus strains from the native range to Europe could pose a threat to the conservation of F. excelsior. In addition, introduction of H. fraxineus to North America could potentially have a negative effect on the indigenous F. pennsylvanica.
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Hymenoscyphus linearis sp. nov: another close relative of the ash dieback pathogen H. fraxineus
Mycological Progress, 2015Co-Authors: A Gross, T. Hosoya, Y.-j. Zhao, H.-o. BaralAbstract:Hymenoscyphus is a large fungal genus containing a single known severe pathogen ( H. fraxineus ) causing ash dieback in Europe. Here, the closely related species Hymenoscyphus linears sp. nov. is described from Japan. Apothecia of this fungus emerge from linear, black pseudosclerotia on rachises and petioles of Fraxinus platypoda . In culture, the species forms a Chalara anamorph similar to that of H. fraxineus. In addition, a Sporotrichum -like synanamorph is produced. Spores of neither anamorphic forms germinate on malt extract agar and might act solely as spermatia. After prolonged incubation, ascocarps are produced directly on agar plates, indicating the ability to self-fertilize. Phylogenetic investigations using four sequence markers placed the species alongside H. albidus , H. albidoides , and H. fraxineus . Eight fungal strains, co-occurring with H. linearis on petioles of F. platypoda, were isolated and identified by sequencing the ITS region of the rDNA. Seven different species were revealed, showing that there is no other dominant fungus on petioles of F. platypoda . Pathogenicity tests on Fraxinus excelsior and its native host F. platypoda revealed that the fungus is avirulent. The close phylogenetic relationship with H. fraxineus and the avirulence of H. linearis offer an opportunity to study the evolution of pathogenicity of H. fraxineus in further detail in the future.
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Hymenoscyphus fraxineus and two new Hymenoscyphus species identified in Korea
Mycological Progress, 2015Co-Authors: A GrossAbstract:Hymenoscyphus fraxineus is an invasive fungal pathogen that causes ash dieback in Europe. Recent investigations have identified H. fraxineus on herbarium specimens in Korea. In this paper, these specimens, plus five additional collections, were studied by internal transcribed spacer (ITS) screening and subsequent phylogenetic analysis using three additional sequence markers (actin, calmodulin, EF1-α). Using the concept of genealogical concordance phylogenetic species recognition (GCPSR), H. fraxineus was confirmed in five of the collections on petioles of Fraxinus mandshurica and F. chinensis subsp. rhynchophylla. The remaining collections revealed two novel species, both occurring on petioles of F. chinensis subsp. rhynchophylla . They are described as Hymenoscyphus occultus sp. nov. and Hymenoscyphus koreanus sp. nov., based on morphological and molecular data. Both develop a Chalara -like anamorph similar to that of H. fraxineus . Together with the newly described H. albidoides from China and H. linearis from Japan, the clade containing H. fraxineus now consists of six species. Within this clade, H. koreanus forms a sister species to H. albidus and both share highly similar morphological and molecular features. Hymenoscyphus occultus is more distantly related to H. fraxineus and shows proximity to H. linearis . Ascocarp production on ash leaf malt-extract agar could be shown for the two new species, and for H. linearis and H. albidus . The experiment demonstrated these species’ ability to self-fertilize. Our findings suggest the diversity of Hymenoscyphus species on Fraxinus sp. might be higher than currently known, calling for further investigations on petioles of other Fraxinus species.
Christine Sambles - One of the best experts on this subject based on the ideXlab platform.
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ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease
Scientific Data, 2017Co-Authors: Christine Sambles, Lene Rostgaard Nielsen, Deborah L. Salmon, Hannah Florance, Thomas P. Howard, Lea Vig Mckinney, Erik Dahl Kjær, Nicholas Smirnoff, Richard J A BuggsAbstract:European common ash, Fraxinus excelsior, is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus. To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus, we performed untargeted metabolomic profiling on leaves from five high-susceptibility and five low-susceptibility F. excelsior individuals identified during Danish field trials. We describe in this study, two datasets. The first is untargeted LC-MS metabolomics raw data from ash leaves with high-susceptibility and low-susceptibility to ADB in positive and negative mode. These data allow the application of peak picking, alignment, gap-filling and retention-time correlation analyses to be performed in alternative ways. The second, a processed dataset containing abundances of aligned features across all samples enables further mining of the data. Here we illustrate the utility of this dataset which has previously been used to identify putative iridoid glycosides, well known anti-herbivory terpenoid derivatives, and show differential abundance in tolerant and susceptible ash samples. Machine-accessible metadata file describing the reported data (ISA-Tab format)
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Ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease
Scientific Data, 2017Co-Authors: Christine Sambles, Deborah L. Salmon, Hannah Florance, Thomas P. Howard, Lene R. Nielsen, Lea Vig Mckinney, Erik Dahl Kjær, Richard J A Buggs, Nicholas Smirnoff, David J. StudholmeAbstract:European common ash, Fraxinus excelsior , is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus . To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus , we performed untargeted metabolomic profiling on leaves from five high-susceptibility and five low-susceptibility F. excelsior individuals identified during Danish field trials. We describe in this study, two datasets. The first is untargeted LC-MS metabolomics raw data from ash leaves with high-susceptibility and low-susceptibility to ADB in positive and negative mode. These data allow the application of peak picking, alignment, gap-filling and retention-time correlation analyses to be performed in alternative ways. The second, a processed dataset containing abundances of aligned features across all samples enables further mining of the data. Here we illustrate the utility of this dataset which has previously been used to identify putative iridoid glycosides, well known anti-herbivory terpenoid derivatives, and show differential abundance in tolerant and susceptible ash samples. Design Type(s) parallel group design • disease analysis objective Measurement Type(s) metabolite profiling Technology Type(s) quadrupole time-of-flight mass spectrometry Factor Type(s) phenotype • experimental condition • age • geographic location • biological replicate Sample Characteristic(s) Fraxinus excelsior • leaf • Kingdom of Denmark Machine-accessible metadata file describing the reported data (ISA-Tab format)
Lea Vig Mckinney - One of the best experts on this subject based on the ideXlab platform.
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Defining the twig fungal communities of Fraxinus species and Fraxinus excelsior genotypes with differences in susceptibility to ash dieback
Fungal Ecology, 2019Co-Authors: Chatchai Kosawang, Lea Vig Mckinney, Erik Dahl Kjær, Helle Sørensen, Adiphol Dilokpimol, David B. Collinge, Lene Rostgaard NielsenAbstract:Abstract Ash dieback disease (caused by Hymenoscyphus fraxineus) has affected European ash species (Fraxinus spp.) in recent decades. However, some Asian and American species of Fraxinus and certain genotypes of Fraxinus excelsior are less affected by the disease. We used ITS1-metabacoding to explore the drivers influencing diversity and composition of the twig fungal communities of Fraxinus species and F. excelsior genotypes. Our results revealed that fungi in the classes Eurotiomycetes and Dothideomycetes were among the most prevalent taxa in both Fraxinus species and F. excelsior genotypes. The diversity of the fungal communities differed significantly among Fraxinus species and could be explained by seed origin. Neither host genotype nor season had a significant effect on the community diversity of F. excelsior genotypes. On the other hand, the composition of twig fungal communities differed significantly among host species and among F. excelsior genotypes, and in F. excelsior there was also a significant effect of season on the composition of the fungal community. We did not find a clear effect of ash dieback susceptibility on either diversity or composition of fungal communities in twigs of Fraxinus species, although the effect was significant on the composition of fungal communities among F. excelsior genotypes. Our results demonstrated differences in fungal communities among species of Fraxinus and of F. excelsior genotypes, suggesting specific relationship between individual host genotypes and endophytic fungi.
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Ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease
Scientific Data, 2017Co-Authors: Christine Sambles, Deborah L. Salmon, Hannah Florance, Thomas P. Howard, Lene R. Nielsen, Lea Vig Mckinney, Erik Dahl Kjær, Richard J A Buggs, Nicholas Smirnoff, David J. StudholmeAbstract:European common ash, Fraxinus excelsior , is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus . To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus , we performed untargeted metabolomic profiling on leaves from five high-susceptibility and five low-susceptibility F. excelsior individuals identified during Danish field trials. We describe in this study, two datasets. The first is untargeted LC-MS metabolomics raw data from ash leaves with high-susceptibility and low-susceptibility to ADB in positive and negative mode. These data allow the application of peak picking, alignment, gap-filling and retention-time correlation analyses to be performed in alternative ways. The second, a processed dataset containing abundances of aligned features across all samples enables further mining of the data. Here we illustrate the utility of this dataset which has previously been used to identify putative iridoid glycosides, well known anti-herbivory terpenoid derivatives, and show differential abundance in tolerant and susceptible ash samples. Design Type(s) parallel group design • disease analysis objective Measurement Type(s) metabolite profiling Technology Type(s) quadrupole time-of-flight mass spectrometry Factor Type(s) phenotype • experimental condition • age • geographic location • biological replicate Sample Characteristic(s) Fraxinus excelsior • leaf • Kingdom of Denmark Machine-accessible metadata file describing the reported data (ISA-Tab format)
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ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease
Scientific Data, 2017Co-Authors: Christine Sambles, Lene Rostgaard Nielsen, Deborah L. Salmon, Hannah Florance, Thomas P. Howard, Lea Vig Mckinney, Erik Dahl Kjær, Nicholas Smirnoff, Richard J A BuggsAbstract:European common ash, Fraxinus excelsior, is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus. To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus, we performed untargeted metabolomic profiling on leaves from five high-susceptibility and five low-susceptibility F. excelsior individuals identified during Danish field trials. We describe in this study, two datasets. The first is untargeted LC-MS metabolomics raw data from ash leaves with high-susceptibility and low-susceptibility to ADB in positive and negative mode. These data allow the application of peak picking, alignment, gap-filling and retention-time correlation analyses to be performed in alternative ways. The second, a processed dataset containing abundances of aligned features across all samples enables further mining of the data. Here we illustrate the utility of this dataset which has previously been used to identify putative iridoid glycosides, well known anti-herbivory terpenoid derivatives, and show differential abundance in tolerant and susceptible ash samples. Machine-accessible metadata file describing the reported data (ISA-Tab format)
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molecular markers for tolerance of european ash Fraxinus excelsior to dieback disease identified using associative transcriptomics
Scientific Reports, 2016Co-Authors: Andrea L Harper, Lenka Havlickova, Fiona Fraser, Martin Trick, Lene Rostgaard Nielsen, Lihong Wang, Lea Vig Mckinney, Yi Li, Alison FellgettAbstract:Tree disease epidemics are a global problem, impacting food security, biodiversity and national economies. The potential for conservation and breeding in trees is hampered by complex genomes and long lifecycles, with most species lacking genomic resources. The European Ash tree Fraxinus excelsior is being devastated by the fungal pathogen Hymenoscyphus fraxineus, which causes ash dieback disease. Taking this system as an example and utilizing Associative Transcriptomics for the first time in a plant pathology study, we discovered gene sequence and gene expression variants across a genetic diversity panel scored for disease symptoms and identified markers strongly associated with canopy damage in infected trees. Using these markers we predicted phenotypes in a test panel of unrelated trees, successfully identifying individuals with a low level of susceptibility to the disease. Co-expression analysis suggested that pre-priming of defence responses may underlie reduced susceptibility to ash dieback.
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genetic variation in dieback resistance in Fraxinus excelsior confirmed by progeny inoculation assay
Forest Pathology, 2015Co-Authors: Albin Lobo, Erik Dahl Kjær, Lea Vig Mckinney, Jon Kehlet Hansen, Lene Rostgaard NielsenAbstract:Summary Ash dieback caused by the pathogenic fungus Hymenoscyphus fraxineus [previously known as H. pseudoalbidus (sexual stage) and Chalara fraxinea (asexual stage)] is a widespread problem in Europe. Here, we assess crown damage from natural infection and necrosis development following artificial controlled inoculations on full-sib and half-sib progeny from Danish Fraxinus excelsior clones with contrasting and well-characterized levels of susceptibility to the disease. The inoculation assay was performed on a total of 123 offspring, and necrosis development monitored over two years. The offspring from low susceptible mother clones developed smaller necroses when compared to offspring from susceptible clones. Their crown damage due to natural infections was also significantly less. The correlation coefficient between average crown damages of mother clones and the average of their progeny was 0.85 (natural infections), while the correlation between crown damage of mother clones and the average necrosis development in their progeny after controlled inoculation was 0.73. The correlation between resistance of parent trees and crown damage/necrosis development on their offspring confirms the presence of heritable resistance and indicates that a bioassay based on controlled inoculations has the potential of becoming a fast and cost-effective tool for estimation of dieback susceptibility in breeding programmes for resistance in ash trees.
Gerard Marigo - One of the best experts on this subject based on the ideXlab platform.
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comparative studies of the water relations and the hydraulic characteristics in Fraxinus excelsior acer pseudoplatanus and a opalus trees under soil water contrasted conditions
Annals of Forest Science, 2001Co-Authors: Damien Lemoine, Jeanpaul Peltier, Gerard MarigoAbstract:Plant water relationships and hydraulic characteristics were measured for two species of the genus Acer that co-occur with Fraxinus excelsior, but differ in their habitat preference with respect to soil moisture: Acer pseudoplatanusis restricted to wet habitats, whereas Acer opalusoccurs on drier sites. The data obtained showed significantly lower hydraulic conductance and lower vulnerability to embolism in the drought-tolerant species, Acer opalus, than in the water prefering species Acer pseudoplatanus. Similar differences in hydraulic conductance and xylem vulnerability to embolism were also found under dry acclimated conditions for Fraxinus excelsior trees, indicating that the hydraulic differences observed might be attributable to the contrasting soil water conditions of the sites. The possible physiological and ecological significance of such differences are discussed, in relation to habitat preference and the distribution of each species. hydraulic conductance / xylem embolism / drought tolerance / Acer pseudoplatanus / Acer opalus / Fraxinus excelsior
Richard J A Buggs - One of the best experts on this subject based on the ideXlab platform.
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ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease
Scientific Data, 2017Co-Authors: Christine Sambles, Lene Rostgaard Nielsen, Deborah L. Salmon, Hannah Florance, Thomas P. Howard, Lea Vig Mckinney, Erik Dahl Kjær, Nicholas Smirnoff, Richard J A BuggsAbstract:European common ash, Fraxinus excelsior, is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus. To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus, we performed untargeted metabolomic profiling on leaves from five high-susceptibility and five low-susceptibility F. excelsior individuals identified during Danish field trials. We describe in this study, two datasets. The first is untargeted LC-MS metabolomics raw data from ash leaves with high-susceptibility and low-susceptibility to ADB in positive and negative mode. These data allow the application of peak picking, alignment, gap-filling and retention-time correlation analyses to be performed in alternative ways. The second, a processed dataset containing abundances of aligned features across all samples enables further mining of the data. Here we illustrate the utility of this dataset which has previously been used to identify putative iridoid glycosides, well known anti-herbivory terpenoid derivatives, and show differential abundance in tolerant and susceptible ash samples. Machine-accessible metadata file describing the reported data (ISA-Tab format)
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Ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease
Scientific Data, 2017Co-Authors: Christine Sambles, Deborah L. Salmon, Hannah Florance, Thomas P. Howard, Lene R. Nielsen, Lea Vig Mckinney, Erik Dahl Kjær, Richard J A Buggs, Nicholas Smirnoff, David J. StudholmeAbstract:European common ash, Fraxinus excelsior , is currently threatened by Ash dieback (ADB) caused by the fungus, Hymenoscyphus fraxineus . To detect and identify metabolites that may be products of pathways important in contributing to resistance against H. fraxineus , we performed untargeted metabolomic profiling on leaves from five high-susceptibility and five low-susceptibility F. excelsior individuals identified during Danish field trials. We describe in this study, two datasets. The first is untargeted LC-MS metabolomics raw data from ash leaves with high-susceptibility and low-susceptibility to ADB in positive and negative mode. These data allow the application of peak picking, alignment, gap-filling and retention-time correlation analyses to be performed in alternative ways. The second, a processed dataset containing abundances of aligned features across all samples enables further mining of the data. Here we illustrate the utility of this dataset which has previously been used to identify putative iridoid glycosides, well known anti-herbivory terpenoid derivatives, and show differential abundance in tolerant and susceptible ash samples. Design Type(s) parallel group design • disease analysis objective Measurement Type(s) metabolite profiling Technology Type(s) quadrupole time-of-flight mass spectrometry Factor Type(s) phenotype • experimental condition • age • geographic location • biological replicate Sample Characteristic(s) Fraxinus excelsior • leaf • Kingdom of Denmark Machine-accessible metadata file describing the reported data (ISA-Tab format)
