Ash dieback assessments on intensive monitoring plots in Germany: influence of stand, site and time on disease progression

Journal of Plant Diseases and Protection, Journal Year: 2024, Volume and Issue: unknown

Published: March 29, 2024

Abstract Since 2002, ash dieback caused by the invasive fungus Hymenoscyphus fraxineus has been observed in Germany. The pathogen and its associated symptoms have fatal consequences for vitality survival of European ( Fraxinus excelsior L.), an economically ecologically important tree species. This study analyses monitoring results eleven intensive plots FraxForFuture research network distributed across Germany focuses on within-stand differences dependence small-scale site properties. A cohort 1365 trees was surveyed six times over three years, testing applying a summer winter version nationally standardised assessment key. main disease (crown basal lesions) were more pronounced areas with higher density, edaphically moist (hydromorphic soils), younger/smaller trees, generally increased time. However, trend time differed between single plots. In case considering only surviving part populations, crown condition even improved 6/11 plots, indicating selection process. Large lesions at beginning observation period very good predictor deadfall probability, especially lower stem diameter. Generally, related highly correlated. Silvicultural management practice past that actively pushed towards moister end water demand spectrum to be questioned light dieback. Cost-intensive re-cultivation future—possibly less dieback-susceptible progenies—should avoid pure stands hydromorphic soil conditions.

Language: Английский

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Fungi associated with fine roots of Fraxinus excelsior affected by ash dieback detected by next-generation sequencing

Journal of Plant Diseases and Protection, Journal Year: 2024, Volume and Issue: 131(5), P. 1373 - 1385

Published: May 4, 2024

Abstract The decline of European ash by dieback caused Hymenoscyphus fraxineus together with stem collar necroses and rots various fungi has been investigated intensively during the last years. Nevertheless, hitherto nearly nothing is known about species diversity fungal rhizobiome trees. Here we fine roots affected trees on 15 sampling sites in 6 federal countries Germany. Fine-root samples have treated three different sample regimes each as root-adhering soil, unsterilized sterilized roots. were pooled to get an overview species-richness area. next-generation sequencing platform Oxford Nanopore MinION was used sequence entire ITS probes. Most abundant phyla all Basidiomycota Ascomycota. Species richness significantly from soil. Surprisingly most genera Mycena , Mycenella Delicatula, them agaricoids saprophytic lifestyle. Eleven Glomeromycota detected abundances, whereas detection H. neglectable.

Language: Английский

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Priming of ash saplings with a low virulent Hymenoscyphus fraxineus strain as a possible disease control approach for reducing symptoms of ash dieback

Journal of Plant Diseases and Protection, Journal Year: 2025, Volume and Issue: 132(2)

Published: Jan. 31, 2025

Language: Английский

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Pathogenic fungi and oomycetes causing dieback on Fraxinus species in the Mediterranean climate change hotspot region

Frontiers in Forests and Global Change, Journal Year: 2023, Volume and Issue: 6

Published: Aug. 25, 2023

Environmental changes are occurring on a global scale, but their effects most pronounced in climate change hotspot zones, such as the Mediterranean basin. Within this area Italy, extending from its southern coasts core of Sea to northernmost pre-Alpine and Alpine regions, is characterized by variety climatic conditions vegetation types. Surveys conducted 2018–2022 forest formations Central-Northern Italy revealed that enhanced warming trend irregular distribution precipitations strongly impacting health Fraxinus species, with some pathogenic fungi oomycetes being important contributing factors decline three main ash species growing there: common ( excelsior ), flowering ornus narrow-leaved angustifolia ). Isolation symptomatic plant material collected countrywide under different site pathogenicity tests complex phytopathological framework, several addition Hymenoscyphus fraxineus involved prominent role dieback etiology. Key microbial taxa included fungal oomycete pathogens Botryosphaeria dothidea , Diplodia fraxini subglobosa Phytophthora acerina plurivora . The disease impact was higher sites where trees grew environmental stress (i.e., areas mild dry winters, hot summers intense prolonged drought) exhibited reduced vigor, also consequence anthropogenic interference silvicultural management fires). identified causative agents emerging thrive warmer conditions, investigated prevalent compared H. which appears be restricted Italian peninsula cooler wetter valleys Alps Apennines.

Language: Английский

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Synergistic negative effects of ash dieback and Armillaria root rot on health and stability of mature ash trees

Forest Ecology and Management, Journal Year: 2025, Volume and Issue: 580, P. 122476 - 122476

Published: Feb. 8, 2025

Language: Английский

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Temperature-related growth limits and wood decay capacity of the warmth-loving fungus Biscogniauxia nummularia in vitro

Frontiers in Fungal Biology, Journal Year: 2025, Volume and Issue: 6

Published: April 11, 2025

Temperature-related growth characteristics and wood decay capacities of Biscogniauxia nummularia strains were analysed in vitro , revealing variability between strains. To model the fitted dose-response curves generated using four-parameter Brain-Cousens hormesis model. The different showed distinct optimum temperatures, with some achieving maximum at 25°C, while others peaked 28°C, depending on tested culture media. Strains also exhibited variation their temperature ranges for measurable growth, tolerating a broader range than others. results study lead to consideration that tolerance as well optimal might be influenced by strains’ geographic origin, those from southern Germany possibly adapted higher temperatures. In terms decay, mass loss caused various differed clearly many cases, suggesting potential strain-dependent differences pathogenicity. Additionally, genetic analysis beta-tubulin DNA region B. specimens examined revealed considerable variations

Language: Английский

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Priming of ash saplings with a low virulent Hymenoscyphus fraxineus strain as a possible disease control approach for reducing symptoms of ash dieback

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: May 9, 2024

Ash dieback is a tree disease caused by the fungal pathogen Hymenoscyphus fraxineus. Since its introduction into Europe, it has widespread and significant losses of European ash, Fraxinus excelsior. Inoculations F. excelsior with low virulent H. fraxineus isolate was assessed as promising method for reducing symptoms associated ash dieback, presumably triggering systemic induced resistance. Two strains were chosen based on observations high in planta virulence. Crude extracts obtained from cultures highly strain more phytotoxic leaf puncture assay than ones strain. UHPLC-DAD-MS/MS data identified phytotoxin viridiol potential hyfraxin A both cultures. However, production these compounds vitro did not correspond virulence planta. To test effects priming, saplings first inoculated subsequently On average, necrosis expansion stems reduced 54% primed at end monitoring period 14 weeks, thus providing proof concept priming. These results contribute to our understanding possible integrated biological control approach increasing resistance damages pathogens, particularly during nursery propagation, out-planting through establishment phase. We discuss context relevant literature summarise limited availability priming underlying principles trees.

Language: Английский

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Load of the ash dieback pathogen hymenoscyphus fraxineus differs in soil

Journal of Plant Diseases and Protection, Journal Year: 2024, Volume and Issue: 131(5), P. 1399 - 1410

Published: July 31, 2024

Abstract The ascomycete Hymenoscyphus fraxineus causes the devastating ash dieback disease of European ( Fraxinus excelsior L.). Spore traps are often used to measure amount ascospores in environment, but pathogen-load soil stands has not been recorded so far. This is particular interest with regard occurrence stem necrosis, a decisive factor for severe course disease. In order gain more differentiated insight into stands, we analysed samples from four tree sites southern Germany, covering clone plantation, two seed orchards and forest. was determined using quantitative TaqMan real-time PCR assay ten twenty plots per stand. Results obtained by species-specific highlighted that heterogeneously distributed stands. H. DNA targets were detected 17% samples. differed according depth, highest pathogen abundance top 5 cm, followed 5–10 cm finally 10–15 cm. Pathogen-load thereby infection pressure found be highly variable individual trees one Overall, study discovered detectable levels all sites, which supports hypothesis can qPCR approach an effective method monitoring load demonstrating successful application on sample type custom-made spore traps. suggest implication site-specific determination future -monitoring selection less susceptible breeding production.

Language: Английский

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Hope for ash conservation and propagation—single individuals can be highly resistant to an invasive pathogen

Journal of Plant Diseases and Protection, Journal Year: 2024, Volume and Issue: 132(1)

Published: Dec. 11, 2024

Abstract Common ash ( Fraxinus excelsior L.) has been considered an important candidate species for climate-resilient forest management in Germany. The occurrence of dieback, caused by the invasive fungus Hymenoscyphus fraxineus , severely limits its use. However, less damaged trees heavily infested stands are observed. This suggests a tree-specific and genetically determined susceptibility to dieback. potential individual selection conservation programs investigated on 35 clones clonal trial 30 families progeny since 2014. Ash dieback-related mortality, crown damage, height growth were examined. Resistance dieback was evaluated based multi-year observations. Mortality ramets occurred rapidly damage stabilized, whereas steadily increasing during study period. About 34 percent all offspring (0–56 per family) showed high resistance 10 also good growth. Broad-sense heritability narrow-sense moderate comparable previous studies. We assume that at least some individuals from specific progenies will resist disease stands. In situ ex strategies should be promoted. Seed orchards with more resistant genotypes could provide susceptible reproductive material, breeding help accelerate fixation favorable alleles.

Language: Английский

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Evaluation and identification of viruses for biocontrol of the ash dieback disease

Journal of Plant Diseases and Protection, Journal Year: 2023, Volume and Issue: unknown

Published: Oct. 5, 2023

Abstract The invasive ascomycete Hymenoscyphus fraxineus is the causative agent for ash dieback on European species Fraxinus excelsior and angustifolia, there concern that it going to replace native, closely related nonpathogenic albidus . Fungal management in forests limited, alternative approaches control are needed. Within scope of project “FraxForFuture”, several strategies being investigated. One idea comprises use a viral hyperparasite, which can induce reduced virulence fungal host H. an antagonist-like system. This phenomenon, reduction by infection, known as hypovirulence, similar method has already been established Chestnut Blight Europe. We examined 34 isolates both their presence infection. Although predominant number were found be infected with mitovirus 1 (HfMV1), no additional viruses detected, our data did not indicate link virulence. search infection was extended one isolate we characterized novel mycovirus. Based phylogenetic analysis sequence properties, assigned genus Victorivirus family Totiviridae tentatively denominated victorivirus 1. native mycovirus might suitable inducing hypovirulence biocide

Language: Английский

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