O. Holdenrieder - Academia.edu (original) (raw)
Papers by O. Holdenrieder
Biological Reviews, 2010
Global change (climate change together with other worldwide anthropogenic processes such as incre... more Global change (climate change together with other worldwide anthropogenic processes such as increasing trade, air pollution and urbanization) will affect plant health at the genetic, individual, population and landscape level. Direct effects include ecosystem stress due to natural resources shortage or imbalance. Indirect effects include (i) an increased frequency of natural detrimental phenomena, (ii) an increased pressure due to already present pests and diseases, (iii) the introduction of new invasive species either as a result of an improved suitability of the climatic conditions or as a result of increased trade, and (iv) the human response to global change. In this review, we provide an overview of recent studies on terrestrial plant health in the presence of global change factors. We summarize the links between climate change and some key issues in plant health, including tree mortality, changes in wildfire regimes, biological invasions and the role of genetic diversity for ecosystem resilience. Prediction and management of global change effects are complicated by interactions between globalization, climate and invasive plants and/or pathogens. We summarize practical guidelines for landscape management and draw general conclusions from an expanding body of literature.
Forest Pathology, 1987
Dothistroma pini sur de jeunes epiceas Sous des conditions microclimatiques favorables, et soumis... more Dothistroma pini sur de jeunes epiceas Sous des conditions microclimatiques favorables, et soumis a un fort inoculum naturel, Picea ahies peut etre infecte par Dothistroma pini. Le champignon acheve son cycle de developpement dans les aiguilles par la production de carpophores et de conidies. Dans cet article Dothistroma pini est decrit pour la premiere fois sur Picea abies.
Ash dieback caused by the mitosporic ascomycete Chalara fraxinea is a novel disease of major conc... more Ash dieback caused by the mitosporic ascomycete Chalara fraxinea is a novel disease of major concern affecting Fraxinus excelsior and Fraxinus angustifolia in large parts of Europe. Recently, its teleomorph was detected and assigned to Hymenoscyphus albidus, which has been known from Europe since 1851. In this study, we present molecular evidence for the existence of two morphologically very similar taxa, H. albidus, which is lectotypified and Hymenoscyphus pseudoalbidus sp. nov. Differences were found between the species in the loci calmodulin, translation elongation factor 1-a and the internal transcribed spacers of the rDNA genes, and strong differentiation was obtained with ISSR markers. It is likely that H. albidus is a non-pathogenic species, whereas H. pseudoalbidus is a virulent species causing ash dieback. Genotyping herbarium specimens showed that H. pseudoalbidus has been present in Switzerland for at least 30 years prior to the outbreak of the epidemic. 1
Forest Diversity and Function
Plant communities commonly have both host diversity and biotic diseases (Kimmins 1997a; Roy and K... more Plant communities commonly have both host diversity and biotic diseases (Kimmins 1997a; Roy and Kirchner 2000), but to differing degrees. Disease and diversity are classically connected in the literature by the co-evolutionary explanation of sex (Hamilton 1980): recombinations of the host genome may produce disease-resistant genotypes, while preserving or enhancing diversity (Clay and Kover 1996; Kirchner and Roy 2000; Lively 2001). We argue here that this concept of species interaction has to be viewed in the ...
Molecular Plant Pathology, 2013
The ascomycete Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea) causes a lethal disease kn... more The ascomycete Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea) causes a lethal disease known as ash dieback on Fraxinus excelsior and Fraxinus angustifolia in Europe. The pathogen was probably introduced from East Asia and the disease emerged in Poland in the early 1990s; the subsequent epidemic is spreading to the entire native distribution range of the host trees. This pathogen profile represents a comprehensive review of the state of research from the discovery of the pathogen and points out knowledge gaps and research needs. Taxonomy: Members of the genus Hymenoscyphus (Helotiales, Leotiomycetidae, Leotiomycetes, Ascomycota) are small discomycetes which form their ascomata on dead plant material. A phylogeny based on the internal transcribed spacers (ITSs) of the rDNA indicated the avirulent Hymenoscyphus albidus, a species native to Europe, as the closest relative of H. pseudoalbidus. Symptoms: Hymenoscyphus pseudoalbidus causes necrotic lesions on leaves, twigs and stems, eventually leading to wilting and dieback of girdled shoots. Bark lesions are characterized by a typical dark-to cinnamon-brown discoloration. Life cycle: Hymenoscyphus pseudoalbidus is heterothallic and reproduces sexually on ash petioles in the litter once a year. Ascospores are wind dispersed and infect ash leaves during the summer. The asexual spores only serve as spermatia. Tools and techniques: The most important techniques for fungal handling, such as detection, isolation, culturing, storage, crossing and ascocarp production, are briefly described. Management: Once the disease is established, management is hardly possible. The occurrence of a small fraction of partially tolerant trees constitutes hope for resistance breeding in the future. Healthy-looking trees should be preserved.
Forest Pathology, 2009
Summary Ash dieback, caused by the pathogen Chalara fraxinea, is an emerging lethal disease of Fr... more Summary Ash dieback, caused by the pathogen Chalara fraxinea, is an emerging lethal disease of Fraxinus excelsior, threatening the host species in large parts of Europe. The ascomycete Hymenoscyphus albidus (Helotiaceae, Helotiales) was identified as the ...
European Journal of Forest Research, 2013
Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) was first introduced to Europe from North Amer... more Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) was first introduced to Europe from North America more than 150 years ago, was then planted on a large scale and is now the economically most important exotic tree species in European forests. This literature review summarizes the current knowledge on the effects of Douglas fir on soil chemistry, plants, arthropods and fungi. Douglas fir shapes its abiotic environment similarly to native tree species such as Norway spruce, silver fir or European beech. In general, many organisms have been shown to be able to live together with Douglas fir and in some cases even benefit from its presence. Although the number of species of the ground vegetation and that of arthropod communities is similar to those of native conifer species, fungal diversity is reduced by Douglas fir. Special microclimatic conditions in the crown of Douglas fir can lead to reduced arthropod densities during winter with possible negative consequences for birds. The ecological impacts of Douglas fir are in general not as severe as those of other exotic tree species, e.g., Pinus spp. in South Africa and Ailanthus altissima, Prunus serotina and Robinia pseudoacacia in Europe. Nonetheless, Douglas fir can negatively impact single groups of organisms or species and is now regenerating itself naturally in Europe. Although Douglas fir has not been the subject of large-scale outbreaks of pests in Europe so far, the further introduction of exotic organisms associated with Douglas fir in its native range could be more problematic than the introduction of Douglas fir itself.
Applied and Environmental Microbiology, 2003
Biological control of plant diseases generally requires release of living organisms into the envi... more Biological control of plant diseases generally requires release of living organisms into the environment. Cryphonectria hypoviruses function as biological control agents for the chestnut blight fungus, Cryphonectria parasitica, and hypovirus-infected C. parasitica strains can be used to treat infected trees. We used naturally occurring molecular marker polymorphisms to examine the persistence and dissemination of the three genomes of a hypovirus-infected C. parasitica strain, namely, the double-stranded RNA genome of Cryphonectria hypovirus 1 (CHV1) and the nuclear and mitochondrial genomes of its fungal host. The hypovirus-infected strain was experimentally introduced into a blight-infested chestnut coppice forest by treating 73 of 246 chestnut blight cankers. Two years after introduction, the hypovirus had disseminated to 36% of the untreated cankers and to 35% of the newly established cankers. Spread of the hypovirus was more frequent within treated sprout clusters than between s...
Plant Pathology
The future existence of common ash (Fraxinus excelsior), an important tree species throughout tem... more The future existence of common ash (Fraxinus excelsior), an important tree species throughout temperate Europe, is threatened. An invasive fungal disease (ash dieback) has spread through much of the distribution area of common ash. The causal agent of the disease is Hymenoscyphus fraxineus, a necrotrophic ascomycete, most probably introduced from Asia in the early 1990s. Hymenoscyphus fraxineus infects ash trees and saplings through their leaves, from which it grows into the stem. The fungus was studied intensively in recent years but there is still a need to address the topic from an evolutionary perspective. In this overview, some key evolutionary aspects of ash dieback are discussed, from the Red Queen dynamics of host-pathogen interactions to the probable consequences for virulence evolution of multiple infections. The progression of ash dieback in Europe does not show spatial differences, but studies show variation in susceptibility within host populations, a probable consequence of genetic differences, thus providing material for evolution of disease resistance or tolerance. Breeding programmes need to maintain the genetic diversity of Fraxinus, to enable it to withstand further threats such as climate change and the emerald ash borer. Because H. fraxineus reproduces exclusively sexually, the pathogen is likely to overcome a narrow genetic resistance. The introduction of further strains of H. fraxineus to Europe and the movement of infected plant material should be avoided. This case study shows that the integration of evolutionary ecology considerations would benefit plant disease management and biosecurity in general.
Plant Disease, 2014
The mitosporic ascomycetes Dothistroma septosporum s.s. (Dorog.) Morelet and D. pini Hulbary are ... more The mitosporic ascomycetes Dothistroma septosporum s.s. (Dorog.) Morelet and D. pini Hulbary are closely related species (1) causing red band needle blight on Pinus spp. D. septosporum (teleomorph Mycosphaerella pini Rostr.) is considered as a cosmopolitan species, whereas D. pini (no teleomorph known) seems to have a more restricted distribution area. Detected in the United States on Pinus nigra for the first time, it was later found in Russia, Ukraine, Hungary, and France on different pine species (P. radiata, P. mugo, P. pallasiana) (3). In Switzerland, Dothistroma sp. (species not further determined) was recorded in 1989 for the first time and since then only damages on planted pines (mainly P. mugo and P. nigra) in urban areas were reported (R. Engesser, personal communication). In September 2012 and in April 2013, several planted mature trees and naturally regenerated young trees of P. nigra with Dothistroma needle blight were detected on a climatically mild forest site on lim...
Oecologia, 1990
Odontia bieolor (Alb. & Schw. ex Fr.) Bres.] is an outcrossing resupinate basidiomycete associate... more Odontia bieolor (Alb. & Schw. ex Fr.) Bres.] is an outcrossing resupinate basidiomycete associated with root and butt rots of trees, but is itself only very weakly pathogenic. The distribution of genets among every spruce stump in a 70-year-old 1250 m z spruce stand was analysed using somatic incompatibility testing. R. bicolor was present on 40% of 8-to 10-year-old stumps. Nineteen genets were found occupying 32 stumps; yielding probabilities of colonisation following establishment by basidiospores of 0.20-0.24 and by mycelial extension or dispersal of 0.16-0.20. The probability of colonisation decreased with increasing distance from a point of establishment. R. bicolor responded to both enrichment and destructive disturbances by the formation of an extensive cord system which enabled it to colonise discontinuously distributed resources and to overgrow fungi adjacent to it in a single resource unit, including Heterobasidion annosum.
Forest Pathology, 2013
ABSTRACT
Schweizerische Zeitschrift Fur Forstwesen, 1998
Biological Reviews, 2010
Global change (climate change together with other worldwide anthropogenic processes such as incre... more Global change (climate change together with other worldwide anthropogenic processes such as increasing trade, air pollution and urbanization) will affect plant health at the genetic, individual, population and landscape level. Direct effects include ecosystem stress due to natural resources shortage or imbalance. Indirect effects include (i) an increased frequency of natural detrimental phenomena, (ii) an increased pressure due to already present pests and diseases, (iii) the introduction of new invasive species either as a result of an improved suitability of the climatic conditions or as a result of increased trade, and (iv) the human response to global change. In this review, we provide an overview of recent studies on terrestrial plant health in the presence of global change factors. We summarize the links between climate change and some key issues in plant health, including tree mortality, changes in wildfire regimes, biological invasions and the role of genetic diversity for ecosystem resilience. Prediction and management of global change effects are complicated by interactions between globalization, climate and invasive plants and/or pathogens. We summarize practical guidelines for landscape management and draw general conclusions from an expanding body of literature.
Forest Pathology, 1987
Dothistroma pini sur de jeunes epiceas Sous des conditions microclimatiques favorables, et soumis... more Dothistroma pini sur de jeunes epiceas Sous des conditions microclimatiques favorables, et soumis a un fort inoculum naturel, Picea ahies peut etre infecte par Dothistroma pini. Le champignon acheve son cycle de developpement dans les aiguilles par la production de carpophores et de conidies. Dans cet article Dothistroma pini est decrit pour la premiere fois sur Picea abies.
Ash dieback caused by the mitosporic ascomycete Chalara fraxinea is a novel disease of major conc... more Ash dieback caused by the mitosporic ascomycete Chalara fraxinea is a novel disease of major concern affecting Fraxinus excelsior and Fraxinus angustifolia in large parts of Europe. Recently, its teleomorph was detected and assigned to Hymenoscyphus albidus, which has been known from Europe since 1851. In this study, we present molecular evidence for the existence of two morphologically very similar taxa, H. albidus, which is lectotypified and Hymenoscyphus pseudoalbidus sp. nov. Differences were found between the species in the loci calmodulin, translation elongation factor 1-a and the internal transcribed spacers of the rDNA genes, and strong differentiation was obtained with ISSR markers. It is likely that H. albidus is a non-pathogenic species, whereas H. pseudoalbidus is a virulent species causing ash dieback. Genotyping herbarium specimens showed that H. pseudoalbidus has been present in Switzerland for at least 30 years prior to the outbreak of the epidemic. 1
Forest Diversity and Function
Plant communities commonly have both host diversity and biotic diseases (Kimmins 1997a; Roy and K... more Plant communities commonly have both host diversity and biotic diseases (Kimmins 1997a; Roy and Kirchner 2000), but to differing degrees. Disease and diversity are classically connected in the literature by the co-evolutionary explanation of sex (Hamilton 1980): recombinations of the host genome may produce disease-resistant genotypes, while preserving or enhancing diversity (Clay and Kover 1996; Kirchner and Roy 2000; Lively 2001). We argue here that this concept of species interaction has to be viewed in the ...
Molecular Plant Pathology, 2013
The ascomycete Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea) causes a lethal disease kn... more The ascomycete Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea) causes a lethal disease known as ash dieback on Fraxinus excelsior and Fraxinus angustifolia in Europe. The pathogen was probably introduced from East Asia and the disease emerged in Poland in the early 1990s; the subsequent epidemic is spreading to the entire native distribution range of the host trees. This pathogen profile represents a comprehensive review of the state of research from the discovery of the pathogen and points out knowledge gaps and research needs. Taxonomy: Members of the genus Hymenoscyphus (Helotiales, Leotiomycetidae, Leotiomycetes, Ascomycota) are small discomycetes which form their ascomata on dead plant material. A phylogeny based on the internal transcribed spacers (ITSs) of the rDNA indicated the avirulent Hymenoscyphus albidus, a species native to Europe, as the closest relative of H. pseudoalbidus. Symptoms: Hymenoscyphus pseudoalbidus causes necrotic lesions on leaves, twigs and stems, eventually leading to wilting and dieback of girdled shoots. Bark lesions are characterized by a typical dark-to cinnamon-brown discoloration. Life cycle: Hymenoscyphus pseudoalbidus is heterothallic and reproduces sexually on ash petioles in the litter once a year. Ascospores are wind dispersed and infect ash leaves during the summer. The asexual spores only serve as spermatia. Tools and techniques: The most important techniques for fungal handling, such as detection, isolation, culturing, storage, crossing and ascocarp production, are briefly described. Management: Once the disease is established, management is hardly possible. The occurrence of a small fraction of partially tolerant trees constitutes hope for resistance breeding in the future. Healthy-looking trees should be preserved.
Forest Pathology, 2009
Summary Ash dieback, caused by the pathogen Chalara fraxinea, is an emerging lethal disease of Fr... more Summary Ash dieback, caused by the pathogen Chalara fraxinea, is an emerging lethal disease of Fraxinus excelsior, threatening the host species in large parts of Europe. The ascomycete Hymenoscyphus albidus (Helotiaceae, Helotiales) was identified as the ...
European Journal of Forest Research, 2013
Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) was first introduced to Europe from North Amer... more Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) was first introduced to Europe from North America more than 150 years ago, was then planted on a large scale and is now the economically most important exotic tree species in European forests. This literature review summarizes the current knowledge on the effects of Douglas fir on soil chemistry, plants, arthropods and fungi. Douglas fir shapes its abiotic environment similarly to native tree species such as Norway spruce, silver fir or European beech. In general, many organisms have been shown to be able to live together with Douglas fir and in some cases even benefit from its presence. Although the number of species of the ground vegetation and that of arthropod communities is similar to those of native conifer species, fungal diversity is reduced by Douglas fir. Special microclimatic conditions in the crown of Douglas fir can lead to reduced arthropod densities during winter with possible negative consequences for birds. The ecological impacts of Douglas fir are in general not as severe as those of other exotic tree species, e.g., Pinus spp. in South Africa and Ailanthus altissima, Prunus serotina and Robinia pseudoacacia in Europe. Nonetheless, Douglas fir can negatively impact single groups of organisms or species and is now regenerating itself naturally in Europe. Although Douglas fir has not been the subject of large-scale outbreaks of pests in Europe so far, the further introduction of exotic organisms associated with Douglas fir in its native range could be more problematic than the introduction of Douglas fir itself.
Applied and Environmental Microbiology, 2003
Biological control of plant diseases generally requires release of living organisms into the envi... more Biological control of plant diseases generally requires release of living organisms into the environment. Cryphonectria hypoviruses function as biological control agents for the chestnut blight fungus, Cryphonectria parasitica, and hypovirus-infected C. parasitica strains can be used to treat infected trees. We used naturally occurring molecular marker polymorphisms to examine the persistence and dissemination of the three genomes of a hypovirus-infected C. parasitica strain, namely, the double-stranded RNA genome of Cryphonectria hypovirus 1 (CHV1) and the nuclear and mitochondrial genomes of its fungal host. The hypovirus-infected strain was experimentally introduced into a blight-infested chestnut coppice forest by treating 73 of 246 chestnut blight cankers. Two years after introduction, the hypovirus had disseminated to 36% of the untreated cankers and to 35% of the newly established cankers. Spread of the hypovirus was more frequent within treated sprout clusters than between s...
Plant Pathology
The future existence of common ash (Fraxinus excelsior), an important tree species throughout tem... more The future existence of common ash (Fraxinus excelsior), an important tree species throughout temperate Europe, is threatened. An invasive fungal disease (ash dieback) has spread through much of the distribution area of common ash. The causal agent of the disease is Hymenoscyphus fraxineus, a necrotrophic ascomycete, most probably introduced from Asia in the early 1990s. Hymenoscyphus fraxineus infects ash trees and saplings through their leaves, from which it grows into the stem. The fungus was studied intensively in recent years but there is still a need to address the topic from an evolutionary perspective. In this overview, some key evolutionary aspects of ash dieback are discussed, from the Red Queen dynamics of host-pathogen interactions to the probable consequences for virulence evolution of multiple infections. The progression of ash dieback in Europe does not show spatial differences, but studies show variation in susceptibility within host populations, a probable consequence of genetic differences, thus providing material for evolution of disease resistance or tolerance. Breeding programmes need to maintain the genetic diversity of Fraxinus, to enable it to withstand further threats such as climate change and the emerald ash borer. Because H. fraxineus reproduces exclusively sexually, the pathogen is likely to overcome a narrow genetic resistance. The introduction of further strains of H. fraxineus to Europe and the movement of infected plant material should be avoided. This case study shows that the integration of evolutionary ecology considerations would benefit plant disease management and biosecurity in general.
Plant Disease, 2014
The mitosporic ascomycetes Dothistroma septosporum s.s. (Dorog.) Morelet and D. pini Hulbary are ... more The mitosporic ascomycetes Dothistroma septosporum s.s. (Dorog.) Morelet and D. pini Hulbary are closely related species (1) causing red band needle blight on Pinus spp. D. septosporum (teleomorph Mycosphaerella pini Rostr.) is considered as a cosmopolitan species, whereas D. pini (no teleomorph known) seems to have a more restricted distribution area. Detected in the United States on Pinus nigra for the first time, it was later found in Russia, Ukraine, Hungary, and France on different pine species (P. radiata, P. mugo, P. pallasiana) (3). In Switzerland, Dothistroma sp. (species not further determined) was recorded in 1989 for the first time and since then only damages on planted pines (mainly P. mugo and P. nigra) in urban areas were reported (R. Engesser, personal communication). In September 2012 and in April 2013, several planted mature trees and naturally regenerated young trees of P. nigra with Dothistroma needle blight were detected on a climatically mild forest site on lim...
Oecologia, 1990
Odontia bieolor (Alb. & Schw. ex Fr.) Bres.] is an outcrossing resupinate basidiomycete associate... more Odontia bieolor (Alb. & Schw. ex Fr.) Bres.] is an outcrossing resupinate basidiomycete associated with root and butt rots of trees, but is itself only very weakly pathogenic. The distribution of genets among every spruce stump in a 70-year-old 1250 m z spruce stand was analysed using somatic incompatibility testing. R. bicolor was present on 40% of 8-to 10-year-old stumps. Nineteen genets were found occupying 32 stumps; yielding probabilities of colonisation following establishment by basidiospores of 0.20-0.24 and by mycelial extension or dispersal of 0.16-0.20. The probability of colonisation decreased with increasing distance from a point of establishment. R. bicolor responded to both enrichment and destructive disturbances by the formation of an extensive cord system which enabled it to colonise discontinuously distributed resources and to overgrow fungi adjacent to it in a single resource unit, including Heterobasidion annosum.
Forest Pathology, 2013
ABSTRACT
Schweizerische Zeitschrift Fur Forstwesen, 1998