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Meger J, Kozioł C, Pałucka M, Burczyk J, Chybicki IJ. Genetic resources of common ash (Fraxinus excelsior L.) in Poland. BMC PLANT BIOLOGY 2024; 24:186. [PMID: 38481155 PMCID: PMC10935948 DOI: 10.1186/s12870-024-04886-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 03/05/2024] [Indexed: 03/17/2024]
Abstract
BACKGROUND Knowledge of genetic structure and the factors that shape it has an impact on forest management practices. European ash (Fraxinus excelsior L.) has declined dramatically throughout its range as a result of a disease caused by the fungus Hymenoscyphus fraxineus. Despite the need for conservation and restoration of the species, genetic data required to guide these efforts at the country level are scarce. Thereofore, we studied the chloroplast and nuclear genetic diversity of 26 natural common ash populations (1269 trees) in Poland. RESULTS Chloroplast polymorphisms grouped the populations into two geographically structured phylogenetic lineages ascribed to different glacial refugia (the Balkans and the Eastern Alps). However, the populations demonstrated high genetic diversity (mean AR = 12.35; mean Ho = 0.769; mean He = 0.542) but low differentiation based on nuclear microsatellites (FST = 0.045). Significant spatial genetic structure, consistent with models of isolation by distance, was detected in 14 out of 23 populations. Estimated effective population size was moderate-to-high, with a harmonic mean of 57.5 individuals per population. CONCLUSIONS Genetic diversity was not homogeneously distributed among populations within phylogenetic gene pools, indicating that ash populations are not equal as potential sources of reproductive material. Genetic differences among populations could be related to their histories, including founder effects or gene flow between evolutionary lineages (admixture). Our results suggest that ash stands across Poland could be treated as two main management units (seed zones). Therefore, despite the homogenizing effect of pollen gene flow known for this species, the genetic structure should be taken into account in the management of the genetic resources of the common ash. Although ash dieback poses an additional challenge for the management of genetic resources, efforts should be directed towards protecting populations with high genetic diversity within defined phylogenetic units, as they may be an important source of adaptive variation for future stands.
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Affiliation(s)
- Joanna Meger
- Department of Genetics, Faculty of Biological Sciences, Kazimierz Wielki University, Chodkiewicza 30, Bydgoszcz, 85-064, Poland.
| | - Czesław Kozioł
- Szklarska Poręba Forest District, Krasińskiego 6, Szklarska Poręba, 58-580, Poland
| | | | - Jarosław Burczyk
- Department of Genetics, Faculty of Biological Sciences, Kazimierz Wielki University, Chodkiewicza 30, Bydgoszcz, 85-064, Poland
| | - Igor J Chybicki
- Department of Genetics, Faculty of Biological Sciences, Kazimierz Wielki University, Chodkiewicza 30, Bydgoszcz, 85-064, Poland.
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Gossner MM, Perret-Gentil A, Britt E, Queloz V, Glauser G, Ladd T, Roe AD, Cleary M, Liziniewicz M, Nielsen LR, Ghosh SK, Bonello P, Eisenring M. A glimmer of hope - ash genotypes with increased resistance to ash dieback pathogen show cross-resistance to emerald ash borer. THE NEW PHYTOLOGIST 2023; 240:1219-1232. [PMID: 37345294 DOI: 10.1111/nph.19068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 05/18/2023] [Indexed: 06/23/2023]
Abstract
Plants rely on cross-resistance traits to defend against multiple, phylogenetically distinct enemies. These traits are often the result of long co-evolutionary histories. Biological invasions can force naïve plants to cope with novel, coincident pests, and pathogens. For example, European ash (Fraxinus excelsior) is substantially threatened by the emerald ash borer (EAB), Agrilus planipennis, a wood-boring beetle, and the ash dieback (ADB) pathogen, Hymenoscyphus fraxineus. Yet, plant cross-resistance traits against novel enemies are poorly explored and it is unknown whether naïve ash trees can defend against novel enemy complexes via cross-resistance mechanisms. To gain mechanistic insights, we quantified EAB performance on grafted replicates of ash genotypes varying in ADB resistance and characterized ash phloem chemistry with targeted and untargeted metabolomics. Emerald ash borer performed better on ADB-susceptible than on ADB-resistant genotypes. Moreover, changes in EAB performance aligned with differences in phloem chemical profiles between ADB-susceptible and ADB-resistant genotypes. We show that intraspecific variation in phloem chemistry in European ash can confer increased cross-resistance to invasive antagonists from different taxonomic kingdoms. Our study suggests that promotion of ADB-resistant ash genotypes may simultaneously help to control the ADB disease and reduce EAB-caused ash losses, which may be critical for the long-term stability of this keystone tree species.
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Affiliation(s)
- Martin M Gossner
- Forest Health & Biotic Interactions, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903, Birmensdorf, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zürich, 8092, Zurich, Switzerland
| | - Anouchka Perret-Gentil
- Forest Health & Biotic Interactions, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903, Birmensdorf, Switzerland
| | - Elisabeth Britt
- Forest Health & Biotic Interactions, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903, Birmensdorf, Switzerland
| | - Valentin Queloz
- Forest Health & Biotic Interactions, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903, Birmensdorf, Switzerland
| | - Gaétan Glauser
- Neuchâtel Platform of Analytical Chemistry, University of Neuchâtel, 2000, Neuchâtel, Switzerland
| | - Tim Ladd
- Great Lakes Forestry Centre, Canadian Forest Service, Natural Resources Canada, ON P6A 2E5, Sault Ste. Marie, ON, Canada
| | - Amanda D Roe
- Great Lakes Forestry Centre, Canadian Forest Service, Natural Resources Canada, ON P6A 2E5, Sault Ste. Marie, ON, Canada
| | - Michelle Cleary
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, SE-234 22, Alnarp, Sweden
| | | | - Lene R Nielsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, 1958, Frederiksberg C, Denmark
| | - Soumya K Ghosh
- Department of Plant Pathology, The Ohio State University, Columbus, 43210, OH, USA
| | - Pierluigi Bonello
- Department of Plant Pathology, The Ohio State University, Columbus, 43210, OH, USA
| | - Michael Eisenring
- Forest Health & Biotic Interactions, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), 8903, Birmensdorf, Switzerland
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Ohse B, Compagnoni A, Farrior CE, McMahon SM, Salguero-Gómez R, Rüger N, Knight TM. Demographic synthesis for global tree species conservation. Trends Ecol Evol 2023; 38:579-590. [PMID: 36822929 DOI: 10.1016/j.tree.2023.01.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 01/16/2023] [Accepted: 01/23/2023] [Indexed: 02/24/2023]
Abstract
Conserving the tree species of the world requires syntheses on which tree species are most vulnerable to pressing threats, such as climate change, invasive pests and pathogens, or selective logging. Here, we review the population and forest dynamics models that, when parameterized with data from population studies, forest inventories, or tree rings, have been used for identifying life-history strategies of species and threat-related changes in population demography and dynamics. The available evidence suggests that slow-growing and/or long-lived species are the most vulnerable. However, a lack of comparative, multi-species studies still challenges more precise predictions of the vulnerability of tree species to threats. Improving data coverage for mortality and recruitment, and accounting for interactions among threats, would greatly advance vulnerability assessments for conservation prioritizations of trees worldwide.
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Affiliation(s)
- Bettina Ohse
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany; Department of Community Ecology, Helmholtz Centre for Environmental Research - UFZ, Halle (Saale), Germany.
| | - Aldo Compagnoni
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany; Institute of Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Caroline E Farrior
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Sean M McMahon
- Forest Global Earth Observatory, Smithsonian Environmental Research Center, Edgewater, MD, USA
| | | | - Nadja Rüger
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany; Department of Economics, University of Leipzig, Leipzig, Germany; Smithsonian Tropical Research Institute, Balboa, Ancón, Panama
| | - Tiffany M Knight
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany; Department of Community Ecology, Helmholtz Centre for Environmental Research - UFZ, Halle (Saale), Germany; Institute of Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
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4
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Pollen Viability of Fraxinus excelsior in Storage Experiments and Investigations on the Potential Effect of Long-Range Transport. FORESTS 2022. [DOI: 10.3390/f13040600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Fragmented ash populations due to ash dieback may lead to a limited gene flow and pollination success. Therefore, the viability of ash pollen plays a major role for the survival of the species. The extent to which the long-distance transport of pollen affects pollen viability was investigated with experiments in a climate chamber using ash pollen samples from a seed orchard in Emmendingen, Germany. Furthermore, experiments with a volumetric pollen trap were conducted. A suitable storage temperature for ash pollen was determined by using four viability tests; TTC test, pollen germination, Alexander’s stain and Acetocarmine. An optimization of the germination medium was performed. We found a strong influence of prevailing temperatures on pollen viability, which decreased faster under warmer conditions. At moderate temperatures, viable pollen could still be observed after 28 days. Thus, a possible successful pollination can also be associated to long-range transported pollen. Storage experiments showed that pollen viability could be maintained longer at temperatures of −20 °C and −80 °C than at 4 °C. In particular, the TTC test has proven to be suitable for determining viability. Therefore, properly stored pollen can be used for breeding programs to support the survival of Fraxinus excelsior.
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George JP, Sanders TGM, Timmermann V, Potočić N, Lang M. European-wide forest monitoring substantiate the neccessity for a joint conservation strategy to rescue European ash species (Fraxinus spp.). Sci Rep 2022; 12:4764. [PMID: 35306516 PMCID: PMC8934346 DOI: 10.1038/s41598-022-08825-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 03/09/2022] [Indexed: 01/16/2023] Open
Abstract
European ash (Fraxinus excelsior) and narrow-leafed ash (F. angustifolia) are keystone forest tree species with a broad ecological amplitude and significant economic importance. Besides global warming both species are currently under significant threat by an invasive fungal pathogen that has been spreading progressively throughout the continent for almost three decades. Ash dieback caused by the ascomycete Hymenoscyphus fraxineus is capable of damaging ash trees of all age classes and often ultimately leads to the death of a tree after years of progressively developing crown defoliation. While studies at national and regional level already suggested rapid decline of ash populations as a result of ash dieback, a comprehensive survey at European level with harmonized crown assessment data across countries could shed more light into the population decline from a pan-European perspective and could also pave the way for a new conservation strategy beyond national boarders. Here we present data from the ICP Forests Level I crown condition monitoring from 27 countries resulting in > 36,000 observations. We found a substantial increase in defoliation and mortality over time indicating that crown defoliation has almost doubled during the last three decades. Hotspots of mortality are currently situated in southern Scandinavia and north-eastern Europe. Overall survival probability after nearly 30 years of infection has already reached a critical value of 0.51, but with large differences among regions (0.20–0.86). Both a Cox proportional hazard model as well as an Aalen additive regression model strongly suggest that survival of ash is significantly lower in locations with excessive water regime and which experienced more extreme precipitation events during the last two decades. Our results underpin the necessity for fast governmental action and joint rescue efforts beyond national borders since overall mean defoliation will likely reach 50% as early as 2030 as suggested by time series forecasting.
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Nielsen LR, Nagy NE, Piqueras S, Kosawang C, Thygesen LG, Hietala AM. Host−Pathogen Interactions in Leaf Petioles of Common Ash and Manchurian Ash Infected with Hymenoscyphus fraxineus. Microorganisms 2022; 10:microorganisms10020375. [PMID: 35208829 PMCID: PMC8875166 DOI: 10.3390/microorganisms10020375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/28/2022] [Accepted: 02/01/2022] [Indexed: 02/04/2023] Open
Abstract
Some common ash trees (Fraxinus excelsior) show tolerance towards shoot dieback caused by the invasive ascomycete Hymenoscyphus fraxineus. Leaf petioles are considered to serve as a pathogen colonization route to the shoots. We compared four common ash clones with variation in disease tolerance, and included the native host, Manchurian ash (Fraxinus mandshurica), as a reference. Tissue colonization, following rachis inoculation by H. fraxineus, was monitored by histochemical observations and a quantitative polymerase chain reaction (qPCR) assay specific to H. fraxineus. Axial spread of the pathogen towards the petiole base occurred primarily within the phloem and parenchyma, tissues rich in starch in healthy petioles. In inoculated petioles, a high content of phenolics surrounded the hyphae, presumably a host defense response. There was a relationship between field performance and susceptibility to leaf infection in three of the four studied common ash clones, i.e., good field performance was associated with a low petiole colonization level and vice versa. Low susceptibility to leaf infection may counteract leaf-to-shoot spread of the pathogen in common ash, but the limited number of clones studied warrants caution and a larger study. The Manchurian ash clone had the highest petiole colonization level, which may suggest that this native host has evolved additional mechanisms to avoid shoot infection.
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Affiliation(s)
- Lene R. Nielsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, 1958 Frederiksberg, Denmark; (S.P.); (C.K.); (L.G.T.)
- Correspondence:
| | - Nina E. Nagy
- Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research (NIBIO), 1431 Ås, Norway;
| | - Sara Piqueras
- Department of Geosciences and Natural Resource Management, University of Copenhagen, 1958 Frederiksberg, Denmark; (S.P.); (C.K.); (L.G.T.)
| | - Chatchai Kosawang
- Department of Geosciences and Natural Resource Management, University of Copenhagen, 1958 Frederiksberg, Denmark; (S.P.); (C.K.); (L.G.T.)
| | - Lisbeth G. Thygesen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, 1958 Frederiksberg, Denmark; (S.P.); (C.K.); (L.G.T.)
| | - Ari M. Hietala
- Norwegian Institute of Bioeconomy Research (NIBIO), 7734 Steinkjer, Norway;
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Priming of Resistance-Related Phenolics: A Study of Plant-Associated Bacteria and Hymenoscyphus fraxineus. Microorganisms 2021; 9:microorganisms9122504. [PMID: 34946104 PMCID: PMC8707895 DOI: 10.3390/microorganisms9122504] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 01/08/2023] Open
Abstract
European ash (Fraxinus excelsior) is highly affected by the pathogenic fungus Hymenoscyphus fraxineus in all of Europe. Increases in plant’s secondary metabolite (SM) production is often linked tol enhanced resistance to stress, both biotic and abiotic. Moreover, plant-associated bacteria have been shown to enhance SM production in inoculated plants. Thus, our hypothesis is that bacteria may boost ash SM production, hence priming the tree’s metabolism and facilitating higher levels of resilience to H. fraxineus. We tested three different ash genotypes and used Paenibacillus sp. and Pseudomonas sp. for inoculation in vitro. Total phenol (TPC), total flavonoid (TFC) and carotenoid contents were measured, as well as the chlorophyll a/b ratio and morphometric growth parameters, in a two-stage trial, whereby seedlings were inoculated with the bacteria during the first stage and with H. fraxineus during the second stage. While the tested bacteria did not positively affect the morphometric growth parameters of ash seedlings, they had a statistically significant effect on TPC, TFC, the chlorophyll a/b ratio and carotenoid content in both stages, thus confirming our hypothesis. Specifically, in ash genotype 64, both bacteria elicited an increase in carotenoid content, TPC and TFC during both stages. Additionally, Pseudomonas sp. inoculated seedlings demonstrated an increase in phenolics after infection with the fungus in both genotypes 64 and 87. Our results indicate that next to genetic selection of the most resilient planting material for ash reforestation, plant-associated bacteria could also be used to boost ash SM production.
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Klesse S, von Arx G, Gossner MM, Hug C, Rigling A, Queloz V. Amplifying feedback loop between growth and wood anatomical characteristics of Fraxinus excelsior explains size-related susceptibility to ash dieback. TREE PHYSIOLOGY 2021; 41:683-696. [PMID: 32705118 DOI: 10.1093/treephys/tpaa091] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
Since the 1990s the invasive fungus Hymenoscyphus fraxineus has caused severe crown dieback and high mortality rates in Fraxinus excelsior in Europe. In addition to a strong genetic control of tolerance to the fungus, previous studies have found landscape heterogeneity to be an additional driver of variability in the severity of dieback symptoms. However, apart from climatic conditions related to heat and humidity influencing fungal infection success, the mechanistic understanding of why smaller or slower-growing trees are more susceptible to dieback remains less well understood. Here, we analyzed three stands in Switzerland with a unique setting of 8 years of data availability of intra-annual diameter growth and annual crown health assessments. We complemented this by ring width and quantitative wood anatomical measurements extending back before the monitoring started to investigate if wood anatomical adjustments can help better explain the size-related dieback phenomenon. We found that slower-growing trees or trees with smaller crowns already before the arrival of the fungus were more susceptible to dieback and mortality. Defoliation directly reduced growth as well as maximum earlywood vessel size, and the positive relationship between vessel size and growth rate caused a positive feedback amplifying and accelerating crown dieback. Measured non-structural carbohydrate (NSC) concentrations in the outermost five rings did not significantly vary between healthy and weakened trees, which translate into large differences in absolute available amount of NSCs. Thus, we hypothesize that a lack of NSCs (mainly sugars) leads to lower turgor pressure and smaller earlywood vessels in the following year. This might impede efficient water transport and photosynthesis, and be responsible for stronger symptoms of dieback and higher mortality rates in smaller and slower-growing trees.
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Affiliation(s)
- Stefan Klesse
- Forest Health and Biotic Interactions Department Swiss Federal Research Institute for Forest, Snow, and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Georg von Arx
- Forest Dynamics Department, Swiss Federal Research Institute for Forest, Snow, and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Martin M Gossner
- Forest Health and Biotic Interactions Department Swiss Federal Research Institute for Forest, Snow, and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- ETH Zurich, Department of Environmental Systems Science, Institute of Terrestrial Ecosystems, Universitätstrasse 8-22, 8092 Zurich, Switzerland
| | - Christian Hug
- Forest Dynamics Department, Swiss Federal Research Institute for Forest, Snow, and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Andreas Rigling
- Forest Dynamics Department, Swiss Federal Research Institute for Forest, Snow, and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Valentin Queloz
- Forest Health and Biotic Interactions Department Swiss Federal Research Institute for Forest, Snow, and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
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George JP, Theroux-Rancourt G, Rungwattana K, Scheffknecht S, Momirovic N, Neuhauser L, Weißenbacher L, Watzinger A, Hietz P. Assessing adaptive and plastic responses in growth and functional traits in a 10-year-old common garden experiment with pedunculate oak ( Quercus robur L.) suggests that directional selection can drive climatic adaptation. Evol Appl 2020; 13:2422-2438. [PMID: 33005231 PMCID: PMC7513705 DOI: 10.1111/eva.13034] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 05/06/2020] [Accepted: 05/26/2020] [Indexed: 01/07/2023] Open
Abstract
Understanding how tree species will respond to a future climate requires reliable and quantitative estimates of intra-specific variation under current climate conditions. We studied three 10-year-old common garden experiments established across a rainfall and drought gradient planted with nearly 10,000 pedunculate oak (Quercus robur L.) trees from ten provenances with known family structure. We aimed at disentangling adaptive and plastic responses for growth (height and diameter at breast height) as well as for leaf and wood functional traits related to adaptation to dry environments. We used restricted maximum likelihood approaches to assess additive genetic variation expressed as narrow-sense heritability (h2), quantitative trait differentiation among provenances (QST), and genotype-by-environment interactions (GxE). We found strong and significant patterns of local adaptation in growth in all three common gardens, suggesting that transfer of seed material should not exceed a climatic distance of approximately 1°C under current climatic conditions, while transfer along precipitation gradients seems to be less stringent. Moreover, heritability reached 0.64 for tree height and 0.67 for dbh at the dry margin of the testing spectrum, suggesting significant additive genetic variation of potential use for future selection and tree breeding. GxE interactions in growth were significant and explained less phenotypic variation than origin of seed source (4% versus 10%). Functional trait variation among provenances was partly related to drought regimes at provenances origins but had moderate explanatory power for growth. We conclude that directional selection, either naturally or through breeding, is the most likely and feasible outcome for pedunculate oak to adapt to warmer and drier climate conditions in the future.
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Affiliation(s)
- Jan-Peter George
- Department of Forest Genetics Federal Research and Training Centre for Forests Natural Hazards and Landscape (BFW) Vienna Austria
- Present address: Tartu Observatory University of Tartu Tõravere Estonia
| | - Guillaume Theroux-Rancourt
- Institute of Botany University of Applied Life Sciences and Natural Resources Vienna (BOKU) Vienna Austria
| | - Kanin Rungwattana
- Institute of Botany University of Applied Life Sciences and Natural Resources Vienna (BOKU) Vienna Austria
- Present address: Department of Botany Faculty of Science Kasetsart University Bangkok Thailand
| | - Susanne Scheffknecht
- Institute of Botany University of Applied Life Sciences and Natural Resources Vienna (BOKU) Vienna Austria
| | - Nevena Momirovic
- Institute of Botany University of Applied Life Sciences and Natural Resources Vienna (BOKU) Vienna Austria
| | - Lea Neuhauser
- Institute of Botany University of Applied Life Sciences and Natural Resources Vienna (BOKU) Vienna Austria
| | - Lambert Weißenbacher
- Department of Forest Genetics Federal Research and Training Centre for Forests Natural Hazards and Landscape (BFW) Vienna Austria
| | - Andrea Watzinger
- Institute of Soil Research University of Applied Life Sciences and Natural Resources Vienna (BOKU) Vienna Austria
| | - Peter Hietz
- Institute of Botany University of Applied Life Sciences and Natural Resources Vienna (BOKU) Vienna Austria
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Trujillo-Moya C, Ganthaler A, Stöggl W, Kranner I, Schüler S, Ertl R, Schlosser S, George JP, Mayr S. RNA-Seq and secondary metabolite analyses reveal a putative defence-transcriptome in Norway spruce (Picea abies) against needle bladder rust (Chrysomyxa rhododendri) infection. BMC Genomics 2020; 21:336. [PMID: 32357832 PMCID: PMC7195740 DOI: 10.1186/s12864-020-6587-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 02/18/2020] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Norway spruce trees in subalpine forests frequently face infections by the needle rust fungus Chrysomyxa rhododendri, which causes significant growth decline and increased mortality of young trees. Yet, it is unknown whether trees actively respond to fungal attack by activating molecular defence responses and/or respective gene expression. RESULTS Here, we report results from an infection experiment, in which the transcriptomes (via RNA-Seq analysis) and phenolic profiles (via UHPLC-MS) of control and infected trees were compared over a period of 39 days. Gene expression between infected and uninfected ramets significantly differed after 21 days of infection and revealed already known, but also novel candidate genes involved in spruce molecular defence against pathogens. CONCLUSIONS Combined RNA-Seq and biochemical data suggest that Norway spruce response to infection by C. rhododendri is restricted locally and primarily activated between 9 and 21 days after infestation, involving a potential isolation of the fungus by a hypersensitive response (HR) associated with an activation of phenolic pathways. Identified key regulatory genes represent a solid basis for further specific analyses in spruce varieties with varying susceptibility, to better characterise resistant clones and to elucidate the resistance mechanism.
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Affiliation(s)
- Carlos Trujillo-Moya
- Federal Research and Training Centre for Forests, Landscape and Natural Hazards (BFW)-Department of Forest Genetics, Seckendorff-Gudent-Weg 8, 1131 Vienna, Austria
| | - Andrea Ganthaler
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Wolfgang Stöggl
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Ilse Kranner
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Silvio Schüler
- Federal Research and Training Centre for Forests, Landscape and Natural Hazards (BFW)- Department of Forest Growth & Silviculture, Seckendorff-Gudent-Weg 8, 1131 Vienna, Austria
| | - Reinhard Ertl
- VetCore Facility for Research, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | - Sarah Schlosser
- VetCore Facility for Research, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | - Jan-Peter George
- Federal Research and Training Centre for Forests, Landscape and Natural Hazards (BFW)-Department of Forest Genetics, Seckendorff-Gudent-Weg 8, 1131 Vienna, Austria
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
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Redondo MA, Stenlid J, Oliva J. Genetic Variation Explains Changes in Susceptibility in a Naïve Host Against an Invasive Forest Pathogen: The Case of Alder and the Phytophthora alni Complex. PHYTOPATHOLOGY 2020; 110:517-525. [PMID: 31552784 DOI: 10.1094/phyto-07-19-0272-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Predicting whether naïve tree populations have the potential to adapt to exotic pathogens is necessary owing to the increasing rate of invasions. Adaptation may occur as a result of natural selection when heritable variation in terms of susceptibility exists in the naïve population. We searched for signs of selection on black alder (Alnus glutinosa) stands growing on riverbanks invaded by two pathogens differing in aggressiveness, namely, Phytophthora uniformis (PU) and Phytophthora × alni (PA). We compared the survival and heritability measures from 72 families originating from six invaded and uninvaded (naïve) sites by performing in vitro inoculations. The results from the inoculations were used to assess the relative contribution of host genetic variation on natural selection. We found putative signs of natural selection on alder exerted by PU but not by PA. For PU, we found a higher survival in families originating from invaded sites compared with uninvaded sites. The narrow sense heritability of susceptibility to PU of uninvaded populations was significantly higher than to PA. Simulated data supported the role of heritable genetic variation on natural selection and discarded a high aggressiveness of PA decreasing the transmission rate as an alternative hypothesis for a slow natural selection. Our findings expand on previous attempts of using heritability as a predictor for the likelihood of natural adaptation of naïve tree populations to invasive pathogens. Measures of genetic variation can be useful for risk assessment purposes or when managing Phytophthora invasions.
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Affiliation(s)
- Miguel A Redondo
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Jan Stenlid
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Jonàs Oliva
- Department of Crop and Forest Sciences, University of Lleida, Lleida, Spain
- Joint Research Unit Agrotecnio, Forest Sciences and Technology Centre of Catalonia, Lleida, Spain
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12
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Evans MR. Will natural resistance result in populations of ash trees remaining in British woodlands after a century of ash dieback disease? ROYAL SOCIETY OPEN SCIENCE 2019; 6:190908. [PMID: 31598257 PMCID: PMC6731731 DOI: 10.1098/rsos.190908] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 07/30/2019] [Indexed: 06/10/2023]
Abstract
Novel pests and diseases are becoming increasingly common, and often cause additional mortality to host species in the newly contacted communities. This can alter the structure of the community up to, and including, the extinction of host species. In the last 20 years, ash dieback (ADB) disease has spread into Europe from East Asia. It has caused substantial mortality in ash tree (Fraxinus excelsior L.) populations. However, a proportion of the individuals in most populations appear to be less susceptible to ADB and resistance seems to have high heritability. These observations have led to suggestions that ash populations may be sustainable after the disease. In order to test this hypothesis, I modified an existing model of UK woodland (parametrized for Wytham Woods, Oxfordshire) to take into account the impact of ADB and allowed offspring to inherit resistance traits from their parent. The results suggest that ash populations would still exist in 100 years, but at lower levels than they are currently. For example, when the initial proportion of resistant individuals is about 10% and heritability of resistance is 0.5, then the population of ash falls to about one-third of present levels. The proportion of individuals initially resistant to ADB had a larger effect on population size after 100 years than the heritability of resistance. The fact that the initial size of the resistant population is important to achieve a high population size in the presence of ADB suggests that a selective breeding programme with the intention of augmenting the natural ash populations would be beneficial.
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Affiliation(s)
- Matthew R. Evans
- School of Biological Sciences, Kadoorie Biological Sciences Building, The University of Hong Kong, Pok Fu Lam Road, Hong Kong, People's Republic of China
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13
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Semizer-Cuming D, Krutovsky KV, Baranchikov YN, Kjӕr ED, Williams CG. Saving the world's ash forests calls for international cooperation now. Nat Ecol Evol 2019; 3:141-144. [PMID: 30532045 DOI: 10.1038/s41559-018-0761-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Devrim Semizer-Cuming
- Department of Forest Genetics and Forest Tree Breeding, Georg-August University of Göttingen, Göttingen, Germany. .,Forest, Nature and Biomass, Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark.
| | - Konstantin V Krutovsky
- Department of Forest Genetics and Forest Tree Breeding, Georg-August University of Göttingen, Göttingen, Germany.,Laboratory of Population Genetics, Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russian Federation.,Laboratory of Forest Genomics, Genome Research and Education Center, Siberian Federal University, Krasnoyarsk, Russian Federation.,Department of Ecosystem Science and Management, Texas A&M University, College Station, TX, USA
| | - Yuri N Baranchikov
- Sukachev Institute of Forest FRC KSC of the Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk, Russian Federation
| | - Erik D Kjӕr
- Forest, Nature and Biomass, Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Claire G Williams
- Department of Environmental Sciences, American University, Washington DC, USA.
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14
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Hill L, Hemery G, Hector A, Brown N. Maintaining ecosystem properties after loss of ash in Great Britain. J Appl Ecol 2019. [DOI: 10.1111/1365-2664.13255] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Louise Hill
- Department of Plant SciencesUniversity of Oxford Oxford UK
| | | | - Andy Hector
- Department of Plant SciencesUniversity of Oxford Oxford UK
| | - Nick Brown
- Department of Plant SciencesUniversity of Oxford Oxford UK
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15
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Advanced spectroscopy-based phenotyping offers a potential solution to the ash dieback epidemic. Sci Rep 2018; 8:17448. [PMID: 30487524 PMCID: PMC6262010 DOI: 10.1038/s41598-018-35770-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 11/08/2018] [Indexed: 01/05/2023] Open
Abstract
Natural and urban forests worldwide are increasingly threatened by global change resulting from human-mediated factors, including invasions by lethal exotic pathogens. Ash dieback (ADB), incited by the alien invasive fungus Hymenoscyphus fraxineus, has caused large-scale population decline of European ash (Fraxinus excelsior) across Europe, and is threatening to functionally extirpate this tree species. Genetically controlled host resistance is a key element to ensure European ash survival and to restore this keystone species where it has been decimated. We know that a low proportion of the natural population of European ash expresses heritable, quantitative resistance that is stable across environments. To exploit this resource for breeding and restoration efforts, tools that allow for effective and efficient, rapid identification and deployment of superior genotypes are now sorely needed. Here we show that Fourier-transform infrared (FT-IR) spectroscopy of phenolic extracts from uninfected bark tissue, coupled with a model based on soft independent modelling of class analogy (SIMCA), can robustly discriminate between ADB-resistant and susceptible European ash. The model was validated with populations of European ash grown across six European countries. Our work demonstrates that this approach can efficiently advance the effort to save such fundamental forest resource in Europe and elsewhere.
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16
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Erichsen EO, Budde KB, Sagheb-Talebi K, Bagnoli F, Vendramin GG, Hansen OK. Hyrcanian forests-Stable rear-edge populations harbouring high genetic diversity of Fraxinus excelsior,
a common European tree species. DIVERS DISTRIB 2018. [DOI: 10.1111/ddi.12783] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Eva Ortvald Erichsen
- Department of Geosciences and Natural Resource Management; University of Copenhagen; Frederiksberg Denmark
| | - Katharina Birgit Budde
- Department of Geosciences and Natural Resource Management; University of Copenhagen; Frederiksberg Denmark
| | - Khosro Sagheb-Talebi
- Research Institute of Forests & Rangelands; Agricultural Research, Education and Extension Organization (AREEO); Tehran Iran
| | - Francesca Bagnoli
- Institute of Biosciences and Bioresources; National Research Council; Sesto Fiorentino (Firenze) Italy
| | | | - Ole Kim Hansen
- Department of Geosciences and Natural Resource Management; University of Copenhagen; Frederiksberg Denmark
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17
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Lobo A, Hansen JK, Hansen LN, Dahl Kjær E. Differences among six woody perennials native to Northern Europe in their level of genetic differentiation and adaptive potential at fine local scale. Ecol Evol 2018; 8:2231-2239. [PMID: 29468039 PMCID: PMC5817134 DOI: 10.1002/ece3.3824] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/13/2017] [Accepted: 12/17/2017] [Indexed: 11/12/2022] Open
Abstract
The ability of perennial species to adapt their phenology to present and future temperature conditions is important for their ability to retain high fitness compared to other competing plant species, pests, and pathogens. Many transplanting studies with forest tree species have previously reported substantial genetic differentiation among populations within their native range. However, the question of "how local is local" is still highly debated in conservation biology because studies on genetic patterns of variation within and among populations at the local scale are limited and scattered. In this study, we compare the level of genetic differentiation among populations of six different perennial plant species based on their variation in spring flushing. We assess the level of additive genetic variation present within the local population. For all six species, we find significant differentiation among populations from sites with mean annual temperature ranging between 7.4°C and 8.4°C. The observed variation can only be partly explained by the climate at the site of origin. Most clear relationship between early flushing and higher average spring temperature is observed for the three wind-pollinated species in the study, while the relations are much less clear for the three insect-pollinated species. This supports that pollination system can influence the balance between genetic drift and natural selection and thereby influence the level of local adaptation in long-lived species. On the positive side, we find that the native populations of woody plant species have maintained high levels of additive genetic variation in spring phenology, although this also differs substantially among the six studied species.
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Affiliation(s)
- Albin Lobo
- Department of Geosciences and Natural Resource Management (IGN)University of CopenhagenFrederiksberg CDenmark
| | - Jon Kehlet Hansen
- Department of Geosciences and Natural Resource Management (IGN)University of CopenhagenFrederiksberg CDenmark
| | - Lars Nørgaard Hansen
- Department of Geosciences and Natural Resource Management (IGN)University of CopenhagenFrederiksberg CDenmark
| | - Erik Dahl Kjær
- Department of Geosciences and Natural Resource Management (IGN)University of CopenhagenFrederiksberg CDenmark
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18
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Sambles CM, Salmon DL, Florance H, Howard TP, Smirnoff N, Nielsen LR, McKinney LV, Kjær ED, Buggs RJA, Studholme DJ, Grant M. Ash leaf metabolomes reveal differences between trees tolerant and susceptible to ash dieback disease. Sci Data 2017; 4:170190. [PMID: 29257137 PMCID: PMC5735976 DOI: 10.1038/sdata.2017.190] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 11/02/2017] [Indexed: 12/31/2022] Open
Abstract
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.
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Affiliation(s)
- Christine M. Sambles
- Biosciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, UK
| | - Deborah L. Salmon
- Biosciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Hannah Florance
- SynthSys, Roger Land Building, Alexander Crum Brown Road, The King’s Buildings, Edinburgh EH9 3FF, UK
| | - Thomas P. Howard
- School of Biology, Devonshire Building, Newcastle University, Newcastle upon, Tyne NE1 7RU, UK
| | - Nicholas Smirnoff
- Biosciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Lene R. Nielsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, Frederiksberg C 1958, Denmark
| | - Lea V. McKinney
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, Frederiksberg C 1958, Denmark
| | - Erik D. Kjær
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, Frederiksberg C 1958, Denmark
| | - Richard J. A. Buggs
- Royal Botanic Gardens Kew, Richmond, Surrey TW9 3AB, UK
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - David J. Studholme
- Biosciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Murray Grant
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, UK
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19
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A first assessment of Fraxinus excelsior (common ash) susceptibility to Hymenoscyphus fraxineus (ash dieback) throughout the British Isles. Sci Rep 2017; 7:16546. [PMID: 29185457 PMCID: PMC5707348 DOI: 10.1038/s41598-017-16706-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/22/2017] [Indexed: 01/15/2023] Open
Abstract
Ash dieback (ADB), caused by Hymenoscyphus fraxineus, has severely damaged a large proportion of ash trees (Fraxinus excelsior) in continental Europe. We have little damage data for the British Isles where the disease was found only five years ago in the Southeast, and is still spreading. A large-scale screening trial to evaluate ADB damage to provenances of F. excelsior sourced from throughout the British Isles was planted in 2013 in the southeast of England. In 2016, we scored trees by their level of ADB damage observed in field at the two worst affected (based on assessments in 2015) of the 14 sites. Significant differences were found in average ADB damage among planting sites and seed source provenances. Trees from certain provenances in Scotland were the least damaged by ADB, whereas trees from Wales and Southeast England were the most badly damaged in both trial sites. Thus the levels of ADB damage currently seen in ash populations in Southeast England may not be an accurate predictor of the damage expected in future throughout the British Isles. Given all provenances contained some healthy trees, a breeding programme to produce genetically variable native ash tree populations with lower ADB susceptibility may be feasible.
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20
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Kosawang C, Amby DB, Bussaban B, McKinney LV, Xu J, Kjær ED, Collinge DB, Nielsen LR. Fungal communities associated with species of Fraxinus tolerant to ash dieback, and their potential for biological control. Fungal Biol 2017; 122:110-120. [PMID: 29458714 DOI: 10.1016/j.funbio.2017.11.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 12/11/2022]
Abstract
Ash dieback, caused by the fungus Hymenoscyphus fraxineus, has threatened ash trees in Europe for more than two decades. However, little is known of how endophytic communities affect the pathogen, and no effective disease management tools are available. While European ash (Fraxinus excelsior) is severely affected by the disease, other more distantly related ash species do not seem to be affected. We hypothesise that fungal endophytic communities of tolerant ash species can protect the species against ash dieback, and that selected endophytes have potential as biocontrol agents. These hypotheses were tested by isolating members of the fungal communities of five tolerant ash species, and identifying them using ITS regions. Candidate endophytes were tested by an in vitro antagonistic assay with H.fraxineus. From a total of 196 isolates we identified 9 fungal orders, 15 families, and 40 species. Fungi in orders Pleosporales, such as Boeremia exigua and Diaporthe spp., and Hypocreales (e.g., Fusarium sp.), were recovered in most communities, suggesting they are common taxa. The in vitro antagonistic assay revealed five species with high antagonistic activity against H. fraxineus. These endophytes were identified based on ITS region as Sclerostagonospora sp., Setomelanomma holmii, Epicoccum nigrum, B. exigua and Fusarium sp. Three of these taxa have been described previously as antagonists of plant pathogenic microbes, and are of interest for future studies of their potential as biological control agents against ash dieback, especially for valuable ash trees in parks and urban areas.
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Affiliation(s)
- Chatchai Kosawang
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark.
| | - Daniel Buchvaldt Amby
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark; Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, Denmark
| | - Boonsom Bussaban
- Department of Biology, Faculty of Science, Chiang Mai University, Thailand; Center of Excellence in Bioresources for Agriculture, Industry and Medicine, Faculty of Science, Chiang Mai University, Thailand
| | - Lea Vig McKinney
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Jing Xu
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Erik D Kjær
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - David B Collinge
- Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, Denmark
| | - Lene Rostgaard Nielsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
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21
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Henry RC, Palmer SC, Watts K, Mitchell RJ, Atkinson N, Travis JM. Tree loss impacts on ecological connectivity: Developing models for assessment. ECOL INFORM 2017. [DOI: 10.1016/j.ecoinf.2017.10.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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22
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Semizer-Cuming D, Kjær ED, Finkeldey R. Gene flow of common ash (Fraxinus excelsior L.) in a fragmented landscape. PLoS One 2017; 12:e0186757. [PMID: 29053740 PMCID: PMC5650178 DOI: 10.1371/journal.pone.0186757] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 10/06/2017] [Indexed: 12/24/2022] Open
Abstract
Gene flow dynamics of common ash (Fraxinus excelsior L.) is affected by several human activities in Central Europe, including habitat fragmentation, agroforestry expansion, controlled and uncontrolled transfer of reproductive material, and a recently introduced emerging infectious disease, ash dieback, caused by Hymenoscyphus fraxineus. Habitat fragmentation may alter genetic connectivity and effective population size, leading to loss of genetic diversity and increased inbreeding in ash populations. Gene flow from cultivated trees in landscapes close to their native counterparts may also influence the adaptability of future generations. The devastating effects of ash dieback have already been observed in both natural and managed populations in continental Europe. However, potential long-term effects of genetic bottlenecks depend on gene flow across fragmented landscapes. For this reason, we studied the genetic connectivity of ash trees in an isolated forest patch of a fragmented landscape in Rösenbeck, Germany. We applied two approaches to parentage analysis to estimate gene flow patterns at the study site. We specifically investigated the presence of background pollination at the landscape level and the degree of genetic isolation between native and cultivated trees. Local meteorological data was utilized to understand the effect of wind on the pollen and seed dispersal patterns. Gender information of the adult trees was considered for calculating the dispersal distances. We found that the majority of the studied seeds (55-64%) and seedlings (75-98%) in the forest patch were fathered and mothered by the trees within the same patch. However, we determined a considerable amount of pollen flow (26-45%) from outside of the study site, representing background pollination at the landscape level. Limited pollen flow was observed from neighbouring cultivated trees (2%). Both pollen and seeds were dispersed in all directions in accordance with the local wind directions. Whereas there was no positive correlation between pollen dispersal distance and wind speed, the correlation between seed dispersal distance and wind speed was significant (0.71, p < 0.001), indicating that strong wind favours long-distance dispersal of ash seeds. Finally, we discussed the implications of establishing gene conservation stands and the use of enrichment planting in the face of ash dieback.
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Affiliation(s)
- Devrim Semizer-Cuming
- Department of Forest Genetics and Forest Tree Breeding, Faculty of Forest Sciences and Forest Ecology, University of Göttingen, Göttingen, Germany
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Erik Dahl Kjær
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Reiner Finkeldey
- Department of Forest Genetics and Forest Tree Breeding, Faculty of Forest Sciences and Forest Ecology, University of Göttingen, Göttingen, Germany
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23
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Muñoz F, Marçais B, Dufour J, Dowkiw A. Rising Out of the Ashes: Additive Genetic Variation for Crown and Collar Resistance to Hymenoscyphus fraxineus in Fraxinus excelsior. PHYTOPATHOLOGY 2016; 106:1535-1543. [PMID: 27349738 DOI: 10.1094/phyto-11-15-0284-r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Since the early 1990s, ash dieback due to the invasive ascomycete Hymenoscyphus fraxineus is threatening Fraxinus excelsior in most of its natural range. Previous studies reported significant levels of genetic variability in susceptibility in F. excelsior either in field or inoculation experiments. The present study was based on a field experiment planted in 1995, 15 years before onset of the disease. Crown and collar status were monitored on 777 trees from 23 open-pollinated progenies originating from three French provenances. Health status was modeled using a Bayesian approach where spatiotemporal effects were explicitly taken into account. Moderate narrow-sense heritability was found for crown dieback (h2 = 0.42). This study is first to show that resistance at the collar level is also heritable (h2 = 0.49 for collar lesions prevalence and h2 = 0.42 for their severity) and that there is significant genetic correlation (r = 0.40) between the severities of crown and collar symptoms. There was no evidence for differences between provenances. Family effects were detected, but computing individual breeding values showed that most of the genetic variation lies within families. In agreement with previous reports, early flushing correlates with healthier crown. Implications of these results in disease management and breeding are discussed.
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Affiliation(s)
- Facundo Muñoz
- First, third, and fourth authors: INRA, UR 0588, Unité Amélioration, Génétique et Physiologie Forestières, CS 40001 Ardon, 45075 Orléans Cedex 2, France; and second author: INRA, Nancy Université, UMR 1136 Interactions Arbres/Microorganismes, IFR 110, F-54280 Champenoux, France
| | - Benoît Marçais
- First, third, and fourth authors: INRA, UR 0588, Unité Amélioration, Génétique et Physiologie Forestières, CS 40001 Ardon, 45075 Orléans Cedex 2, France; and second author: INRA, Nancy Université, UMR 1136 Interactions Arbres/Microorganismes, IFR 110, F-54280 Champenoux, France
| | - Jean Dufour
- First, third, and fourth authors: INRA, UR 0588, Unité Amélioration, Génétique et Physiologie Forestières, CS 40001 Ardon, 45075 Orléans Cedex 2, France; and second author: INRA, Nancy Université, UMR 1136 Interactions Arbres/Microorganismes, IFR 110, F-54280 Champenoux, France
| | - Arnaud Dowkiw
- First, third, and fourth authors: INRA, UR 0588, Unité Amélioration, Génétique et Physiologie Forestières, CS 40001 Ardon, 45075 Orléans Cedex 2, France; and second author: INRA, Nancy Université, UMR 1136 Interactions Arbres/Microorganismes, IFR 110, F-54280 Champenoux, France
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24
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Imam J, Singh PK, Shukla P. Plant Microbe Interactions in Post Genomic Era: Perspectives and Applications. Front Microbiol 2016; 7:1488. [PMID: 27725809 PMCID: PMC5035750 DOI: 10.3389/fmicb.2016.01488] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/07/2016] [Indexed: 01/17/2023] Open
Abstract
Deciphering plant-microbe interactions is a promising aspect to understand the benefits and the pathogenic effect of microbes and crop improvement. The advancement in sequencing technologies and various 'omics' tool has impressively accelerated the research in biological sciences in this area. The recent and ongoing developments provide a unique approach to describing these intricate interactions and test hypotheses. In the present review, we discuss the role of plant-pathogen interaction in crop improvement. The plant innate immunity has always been an important aspect of research and leads to some interesting information like the adaptation of unique immune mechanisms of plants against pathogens. The development of new techniques in the post - genomic era has greatly enhanced our understanding of the regulation of plant defense mechanisms against pathogens. The present review also provides an overview of beneficial plant-microbe interactions with special reference to Agrobacterium tumefaciens-plant interactions where plant derived signal molecules and plant immune responses are important in pathogenicity and transformation efficiency. The construction of various Genome-scale metabolic models of microorganisms and plants presented a better understanding of all metabolic interactions activated during the interactions. This review also lists the emerging repertoire of phytopathogens and its impact on plant disease resistance. Outline of different aspects of plant-pathogen interactions is presented in this review to bridge the gap between plant microbial ecology and their immune responses.
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Affiliation(s)
| | | | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand UniversityRohtak, India
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25
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Perry A, Wachowiak W, Brown AV, Ennos RA, Cottrell JE, Cavers S. Substantial heritable variation for susceptibility to Dothistroma septosporum within populations of native British Scots pine ( Pinus sylvestris). PLANT PATHOLOGY 2016; 65:987-996. [PMID: 27587900 PMCID: PMC4984854 DOI: 10.1111/ppa.12528] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The threat from pests and pathogens to native and commercially planted forest trees is unprecedented and expected to increase under climate change. The degree to which forests respond to threats from pathogens depends on their adaptive capacity, which is determined largely by genetically controlled variation in susceptibility of the individual trees within them and the heritability and evolvability of this trait. The most significant current threat to the economically and ecologically important species Scots pine (Pinus sylvestris) is dothistroma needle blight (DNB), caused by the foliar pathogen Dothistroma septosporum. A progeny-population trial of 4-year-old Scots pine trees, comprising six populations from native Caledonian pinewoods each with three to five families in seven blocks, was artificially inoculated using a single isolate of D. septosporum. Susceptibility to D. septosporum, assessed as the percentage of non-green needles, was measured regularly over a period of 61 days following inoculation, during which plants were maintained in conditions ideal for DNB development (warm; high humidity; high leaf wetness). There were significant differences in susceptibility to D. septosporum among families indicating that variation in this trait is heritable, with high estimates of narrow-sense heritability (0.38-0.75) and evolvability (genetic coefficient of variation, 23.47). It is concluded that native Scots pine populations contain sufficient genetic diversity to evolve lower susceptibility to D. septosporum through natural selection in response to increased prevalence of this pathogen.
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Affiliation(s)
- A Perry
- Centre for Ecology and Hydrology Bush Estate Penicuik Midlothian EH26 0QB UK
| | - W Wachowiak
- Centre for Ecology and Hydrology Bush Estate Penicuik Midlothian EH26 0QB UK; Institute of Dendrology Polish Academy of Sciences Parkowa 562-035 Kórnik Poland
| | - A V Brown
- Forestry Commission 231 Corstorphine Road EH12 7AT UK
| | - R A Ennos
- Institute of Evolutionary Biology The University of Edinburgh Ashworth Building Charlotte Auerbach Road, King's Buildings Edinburgh EH9 3JF UK
| | - J E Cottrell
- Forest Research Northern Research Station Roslin Midlothian EH25 9SY UK
| | - S Cavers
- Centre for Ecology and Hydrology Bush Estate Penicuik Midlothian EH26 0QB UK
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26
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Development of Ash Dieback in South-Eastern Germany and the Increasing Occurrence of Secondary Pathogens. FORESTS 2016. [DOI: 10.3390/f7020041] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mitchell RJ, Pakeman RJ, Broome A, Beaton JK, Bellamy PE, Brooker RW, Ellis CJ, Hester AJ, Hodgetts NG, Iason GR, Littlewood NA, Pozsgai G, Ramsay S, Riach D, Stockan JA, Taylor AFS, Woodward S. How to Replicate the Functions and Biodiversity of a Threatened Tree Species? The Case of Fraxinus excelsior in Britain. Ecosystems 2016. [DOI: 10.1007/s10021-015-9953-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Harper AL, McKinney LV, Nielsen LR, Havlickova L, Li Y, Trick M, Fraser F, Wang L, Fellgett A, Sollars ESA, Janacek SH, Downie JA, Buggs RJA, Kjær ED, Bancroft I. Molecular markers for tolerance of European ash (Fraxinus excelsior) to dieback disease identified using Associative Transcriptomics. Sci Rep 2016; 6:19335. [PMID: 26757823 PMCID: PMC4725942 DOI: 10.1038/srep19335] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 12/07/2015] [Indexed: 11/24/2022] Open
Abstract
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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Affiliation(s)
| | - Lea Vig McKinney
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Lene Rostgaard Nielsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | | | - Yi Li
- Department of Biology, University of York, York, UK
| | - Martin Trick
- Computational and Systems Biology, John Innes Centre, Norwich, UK
| | - Fiona Fraser
- Department of Crop Genetics, John Innes Centre, Norwich, UK
| | - Lihong Wang
- Department of Biology, University of York, York, UK
| | | | | | | | - J. Allan Downie
- Department of Molecular Microbiology, John Innes Centre, Norwich, UK
| | - Richard. J. A. Buggs
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Erik Dahl Kjær
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Ian Bancroft
- Department of Biology, University of York, York, UK
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Cleary MR, Andersson PF, Broberg A, Elfstrand M, Daniel G, Stenlid J. Genotypes of Fraxinus excelsior with different susceptibility to the ash dieback pathogen Hymenoscyphus pseudoalbidus and their response to the phytotoxin viridiol - a metabolomic and microscopic study. PHYTOCHEMISTRY 2014; 102:115-25. [PMID: 24709032 DOI: 10.1016/j.phytochem.2014.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 03/03/2014] [Accepted: 03/06/2014] [Indexed: 05/26/2023]
Abstract
Eight European ash (Fraxinus excelsior) genotypes with different known susceptibility to Hymenoscyphus pseudoalbidus were tested against the phytotoxin viridiol and their response described at the microscopic and metabolomic level. All ash genotypes were sensitive to the toxin and necrosis was detectable after 24h. Among the three viridiol concentrations used in the experiment, the lowest concentration (14.7μM) yielded markedly lower mean damage scores compared to those resulting from seedlings tested at higher dosages. The highest damage scores were associated with the susceptible ash clones S-101, S-106 and S-125, but also with resistant clone R-104. Three resistant clones (R-131, R-121, and R-118) had lower mean damage scores compared to susceptible clones. Wilting of leaves was more common 48h after treatment and more pronounced on seedlings with high damage scores. The resulting lesions generally lacked browning of tissue and displayed only surface disruption of cells in direct contact with the toxin. A delay in symptom development was evident on all five resistant clones tested with the two higher concentrations of viridiol. LC-HRMS and MS/MS analyses of ash seedling extracts suggest several secoiridoid compounds as well as compounds related to abscisic acid (ABA) to be produced in response to viridiol. ABA-cysteine and xanthoxin were found at significantly higher concentrations in susceptible clones compared to resistant clones after treatment with viridiol, suggesting a primary role of ABA in response to stress. The results observed in this study suggest that genetic resistance to H. pseudoalbidus among ash genotypes may be explained, in part, by the varied response to phytotoxins produced by the fungus.
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Affiliation(s)
- M R Cleary
- Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Almas allé 5, PO Box 7026, SE-750 07 Uppsala, Sweden.
| | - P F Andersson
- Department of Chemistry and Biotechnology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Almas allé 5, PO Box 7015, SE-750 07 Uppsala, Sweden
| | - A Broberg
- Department of Chemistry and Biotechnology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Almas allé 5, PO Box 7015, SE-750 07 Uppsala, Sweden
| | - M Elfstrand
- Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Almas allé 5, PO Box 7026, SE-750 07 Uppsala, Sweden
| | - G Daniel
- Department of Forest Products, Swedish University of Agricultural Sciences, Vallvägen 9C, PO Box 7008, 750-07 Uppsala, Sweden
| | - J Stenlid
- Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Almas allé 5, PO Box 7026, SE-750 07 Uppsala, Sweden
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Gross A, Holdenrieder O, Pautasso M, Queloz V, Sieber TN. Hymenoscyphus pseudoalbidus, the causal agent of European ash dieback. MOLECULAR PLANT PATHOLOGY 2014; 15:5-21. [PMID: 24118686 PMCID: PMC6638674 DOI: 10.1111/mpp.12073] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
UNLABELLED 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.
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Affiliation(s)
- Andrin Gross
- Forest Pathology and Dendrology, Institute of Integrative Biology (IBZ), ETH Zurich, 8092, Zurich, Switzerland
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Hayden KJ, Garbelotto M, Dodd R, Wright JW. Scaling up from greenhouse resistance to fitness in the field for a host of an emerging forest disease. Evol Appl 2013; 6:970-82. [PMID: 24062805 PMCID: PMC3779097 DOI: 10.1111/eva.12080] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 03/14/2013] [Accepted: 04/09/2013] [Indexed: 12/28/2022] Open
Abstract
Forest systems are increasingly threatened by emergent, exotic diseases, yet management strategies for forest trees may be hindered by long generation times and scant background knowledge. We tested whether nursery disease resistance and growth traits have predictive value for the conservation of Notholithocarpus densiflorus, the host most susceptible to sudden oak death. We established three experimental populations to assess nursery growth and resistance to Phytophthora ramorum, and correlations between nursery-derived breeding values with seedling survival in a field disease trial. Estimates of nursery traits' heritability were low to moderate, with lowest estimates for resistance traits. Within the field trial, survival likelihood was increased in larger seedlings and decreased with the development of disease symptoms. The seed-parent family wide likelihood of survival was likewise correlated with family predictors for size and resistance to disease in 2nd year laboratory assays, though not resistance in 1st year leaf assays. We identified traits and seedling families with increased survivorship in planted tanoaks, and a framework to further identify seed parents favored for restoration. The additive genetic variation and seedling disease dynamics we describe hold promise to refine current disease models and expand the understanding of evolutionary dynamics of emergent infectious diseases in highly susceptible hosts.
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Affiliation(s)
- Katherine J Hayden
- Environmental Science Policy, and Management, University of California Berkeley, CA, USA
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Cobb RC, Rizzo DM, Hayden KJ, Garbelotto M, Filipe JAN, Gilligan CA, Dillon WW, Meentemeyer RK, Valachovic YS, Goheen E, Swiecki TJ, Hansen EM, Frankel SJ. Biodiversity Conservation in the Face of Dramatic Forest Disease: An Integrated Conservation Strategy for Tanoak (Notholithocarpus densiflorus) Threatened by Sudden Oak Death. ACTA ACUST UNITED AC 2013. [DOI: 10.3120/0024-9637-60.2.151] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Gross A, Zaffarano P, Duo A, Grünig C. Reproductive mode and life cycle of the ash dieback pathogen Hymenoscyphus pseudoalbidus. Fungal Genet Biol 2012; 49:977-86. [DOI: 10.1016/j.fgb.2012.08.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 08/16/2012] [Accepted: 08/27/2012] [Indexed: 10/27/2022]
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