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Ramírez Martínez J, Guillou S, Le Prieur S, Di Vittorio P, Bonal F, Taliadoros D, Gueret E, Fournier E, Stukenbrock EH, Valade R, Gladieux P. Deep population structure linked to host vernalization requirement in the barley net blotch fungal pathogen. Microb Genom 2024; 10:001241. [PMID: 38713188 PMCID: PMC11170133 DOI: 10.1099/mgen.0.001241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 04/09/2024] [Indexed: 05/08/2024] Open
Abstract
Invasive fungal pathogens pose a substantial threat to widely cultivated crop species, owing to their capacity to adapt to new hosts and new environmental conditions. Gaining insights into the demographic history of these pathogens and unravelling the mechanisms driving coevolutionary processes are crucial for developing durably effective disease management programmes. Pyrenophora teres is a significant fungal pathogen of barley, consisting of two lineages, Ptt and Ptm, with global distributions and demographic histories reflecting barley domestication and spread. However, the factors influencing the population structure of P. teres remain poorly understood, despite the varietal and environmental heterogeneity of barley agrosystems. Here, we report on the population genomic structure of P. teres in France and globally. We used genotyping-by-sequencing to show that Ptt and Ptm can coexist in the same area in France, with Ptt predominating. Furthermore, we showed that differences in the vernalization requirement of barley varieties were associated with population differentiation within Ptt in France and at a global scale, with one population cluster found on spring barley and another population cluster found on winter barley. Our results demonstrate how cultivation conditions, possibly associated with genetic differences between host populations, can be associated with the maintenance of divergent invasive pathogen populations coexisting over large geographic areas. This study not only advances our understanding of the coevolutionary dynamics of the Pt-barley pathosystem but also prompts further research on the relative contributions of adaptation to the host versus adaptation to abiotic conditions in shaping Ptt populations.
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Affiliation(s)
- Julie Ramírez Martínez
- PHIM Plant Health Institute, Univ. Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Sonia Guillou
- PHIM Plant Health Institute, Univ. Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | | | - Pauline Di Vittorio
- PHIM Plant Health Institute, Univ. Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Florelle Bonal
- UMR AGAP (Amélioration génétique et adaptation des plantes), Montpellier, France
| | - Demetris Taliadoros
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany
- Christian-Albrechts University of Kiel, Am Botanischen Garten 9-11, 24118, Kiel, Germany
| | - Elise Gueret
- MGX-Montpellier GenomiX, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Elisabeth Fournier
- PHIM Plant Health Institute, Univ. Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Eva H. Stukenbrock
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany
- Christian-Albrechts University of Kiel, Am Botanischen Garten 9-11, 24118, Kiel, Germany
| | | | - Pierre Gladieux
- PHIM Plant Health Institute, Univ. Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
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2
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Ahmad F, Diez JJ. Spanish ecological battleground: population structure of two invasive fungi, Cryphonectria parasitica and Fusarium circinatum. FRONTIERS IN PLANT SCIENCE 2023; 14:1310254. [PMID: 38186600 PMCID: PMC10771289 DOI: 10.3389/fpls.2023.1310254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 11/27/2023] [Indexed: 01/09/2024]
Abstract
Introduction Invasive fungi distributed worldwide through globalization have caused devastating diseases in different forests, causing economic and ecologic disturbances. Two such invasive species are Cryphonectria parasitica and Fusarium circinatum, which were introduced to Europe from North America, separated temporally: C. parasitica was introduced about nine decades ago, whereas F. circinatum was introduced around two decades ago. As C. parasitica had a longer time to undergo genetic changes, we hypothesized that it has higher genetic diversity than the recently introduced F. circinatum in Spain. In addition, we studied the genetic characterization of both fungi present in similar ecological conditions in Northern Spain with the aim of providing data for biocontrol measures. Methods Molecular genetic markers were used to test these hypotheses, including mating type and DNA sequencing of internal transcribed spacer (ITS) regions. In addition, we used vegetative compatibility (VC) type markers in C. parasitica as the information about VC type is essential to apply biocontrol against the fungus. Results and discussion All the isolates of C. parasitica from the studied area belonged to only one VC type (EU-1) and one mating type (MAT-2). However, three distinct haplotypes of C. parasitica were identified through ITS sequencing, showing that multiple introductions might have happened to Cantabria. Among F. circinatum, no diversity was observed in ITS and MAT loci in the studied area but isolates from other Spanish regions showed the presence of both mating types. Overall, C. parasitica had higher genetic diversity than F. circinatum, despite both organisms appearing to reproduce clonally. This study helped understand the invasion patterns of C. parasitica and F. circinatum in northern Spain and will be useful in applying biocontrol measures against both pathogens.
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Affiliation(s)
- Farooq Ahmad
- Department of Plant Production and Forest Resources, University of Valladolid, Palencia, Spain
- Sustainable Forest Management Research Institute, University of Valladolid and INIA, Palencia, Spain
| | - Julio Javier Diez
- Department of Plant Production and Forest Resources, University of Valladolid, Palencia, Spain
- Sustainable Forest Management Research Institute, University of Valladolid and INIA, Palencia, Spain
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3
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Drott MT, Park SC, Wang YW, Harrow L, Keller NP, Pringle A. Pangenomics of the death cap mushroom Amanita phalloides, and of Agaricales, reveals dynamic evolution of toxin genes in an invasive range. THE ISME JOURNAL 2023:10.1038/s41396-023-01432-x. [PMID: 37221394 DOI: 10.1038/s41396-023-01432-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 05/01/2023] [Accepted: 05/04/2023] [Indexed: 05/25/2023]
Abstract
The poisonous European mushroom Amanita phalloides (the "death cap") is invading California. Whether the death caps' toxic secondary metabolites are evolving as it invades is unknown. We developed a bioinformatic pipeline to identify the MSDIN genes underpinning toxicity and probed 88 death cap genomes from an invasive Californian population and from the European range, discovering a previously unsuspected diversity of MSDINs made up of both core and accessory elements. Each death cap individual possesses a unique suite of MSDINs, and toxin genes are significantly differentiated between Californian and European samples. MSDIN genes are maintained by strong natural selection, and chemical profiling confirms MSDIN genes are expressed and result in distinct phenotypes; our chemical profiling also identified a new MSDIN peptide. Toxin genes are physically clustered within genomes. We contextualize our discoveries by probing for MSDINs in genomes from across the order Agaricales, revealing MSDIN diversity originated in independent gene family expansions among genera. We also report the discovery of an MSDIN in an Amanita outside the "lethal Amanitas" clade. Finally, the identification of an MSDIN gene and its associated processing gene (POPB) in Clavaria fumosa suggest the origin of MSDINs is older than previously suspected. The dynamic evolution of MSDINs underscores their potential to mediate ecological interactions, implicating MSDINs in the ongoing invasion. Our data change the understanding of the evolutionary history of poisonous mushrooms, emphasizing striking parallels to convergently evolved animal toxins. Our pipeline provides a roadmap for exploring secondary metabolites in other basidiomycetes and will enable drug prospecting.
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Affiliation(s)
- Milton T Drott
- Department of Medical Microbiology and Immunology, Department of Bacteriology, University of Wisconsin, Madison, WI, USA.
- USDA-ARS Cereal Disease Laboratory, St. Paul, MN, USA.
| | - Sung Chul Park
- Department of Medical Microbiology and Immunology, Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Yen-Wen Wang
- Departments of Botany and Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Lynn Harrow
- Departments of Botany and Bacteriology, University of Wisconsin, Madison, WI, USA
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, Department of Bacteriology, University of Wisconsin, Madison, WI, USA.
| | - Anne Pringle
- Departments of Botany and Bacteriology, University of Wisconsin, Madison, WI, USA.
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4
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Rogério F, Van Oosterhout C, Ciampi-Guillardi M, Correr FH, Hosaka GK, Cros-Arteil S, Rodrigues Alves Margarido G, Massola Júnior NS, Gladieux P. Means, motive and opportunity for biological invasions: Genetic introgression in a fungal pathogen. Mol Ecol 2023; 32:2428-2442. [PMID: 35076152 DOI: 10.1111/mec.16366] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 01/07/2022] [Accepted: 01/13/2022] [Indexed: 11/28/2022]
Abstract
Invasions by fungal plant pathogens pose a significant threat to the health of agricultural ecosystems. Despite limited standing genetic variation, many invasive fungal species can adapt and spread rapidly, resulting in significant losses to crop yields. Here, we report on the population genomics of Colletotrichum truncatum, a polyphagous pathogen that can infect more than 460 plant species, and an invasive pathogen of soybean in Brazil. We study the whole-genome sequences of 18 isolates representing 10 fields from two major regions of soybean production. We show that Brazilian C. truncatum is subdivided into three phylogenetically distinct lineages that exchange genetic variation through hybridization. Introgression affects 2%-30% of the nucleotides of genomes and varies widely between the lineages. We find that introgressed regions comprise secreted protein-encoding genes, suggesting possible co-evolutionary targets for selection in those regions. We highlight the inherent vulnerability of genetically uniform crops in the agro-ecological environment, particularly when faced with pathogens that can take full advantage of the opportunities offered by an increasingly globalized world. Finally, we discuss "the means, motive and opportunity" of fungal pathogens and how they can become invasive species of crops. We call for more population genomic studies because such analyses can help identify geographical areas and pathogens that pose a risk, thereby helping to inform control strategies to better protect crops in the future.
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Affiliation(s)
- Flávia Rogério
- Department of Plant Pathology and Nematology, University of São Paulo, Piracicaba, SP, Brazil
- Institute for Agribiotechnology Research (CIALE), University of Salamanca, Salamanca, Spain
| | | | - Maisa Ciampi-Guillardi
- Department of Plant Pathology and Nematology, University of São Paulo, Piracicaba, SP, Brazil
| | | | | | | | | | - Nelson S Massola Júnior
- Department of Plant Pathology and Nematology, University of São Paulo, Piracicaba, SP, Brazil
| | - Pierre Gladieux
- UMR PHIM, University of Montpellier, INRAE, CIRAD, Montpellier, France
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5
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Feau N, Dhillon BD, Sakalidis M, Dale AL, Søndreli KL, Goodwin SB, LeBoldus JM, Hamelin RC. Forest health in the Anthropocene: the emergence of a novel tree disease is associated with poplar cultivation. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220008. [PMID: 36744569 PMCID: PMC9900707 DOI: 10.1098/rstb.2022.0008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Plant domestication and movement are large contributors to the success of new diseases. The introduction of new host species can result in accelerated evolutionary changes in pathogens, affecting long-established coevolutionary dynamics. This has been observed in poplars where severe epidemics of pathogens that were innocuous in their natural pathosystems occurred following host domestication. The North American fungus Sphaerulina musiva is responsible for endemic leaf spots on Populus deltoides. We show that the expansion of poplar cultivation resulted in the emergence of a new lineage of this pathogen that causes stem infections on a new host, P. balsamifera. This suggests a host shift since this is not a known host. Genome analysis of this emerging lineage reveals a mosaic pattern with islands of diversity separated by fixed genome regions, which is consistent with a homoploid hybridization event between two individuals that produced a hybrid swarm. Genome regions of extreme divergence and low diversity are enriched in genes involved in host-pathogen interactions. The specialization of this emerging lineage to a new host and its clonal propagation represents a serious threat to poplars and could affect both natural and planted forests. This work provides a clear example of the changes created by the intensification of tree cultivation that facilitate the emergence of specialized pathogens, jeopardizing the natural equilibrium between hosts and pathogens. This article is part of the theme issue 'Infectious disease ecology and evolution in a changing world'.
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Affiliation(s)
- Nicolas Feau
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada, VT6 1Z4,Pacific Forestry Centre, Canadian Forest Service, Natural Resources Canada, Victoria, BC, Canada, V8Z 1M5
| | - Braham D. Dhillon
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada, VT6 1Z4,Department of Plant Pathology, University of Florida - Fort Lauderdale Research and Education Center, Davie, FL 33314, USA
| | - Monique Sakalidis
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada, VT6 1Z4,Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA,Department of Forestry, Michigan State University, East Lansing, MI 48824, USA
| | - Angela L. Dale
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada, VT6 1Z4,GC-New Construction Materials, FPInnovations, Vancouver, BC, Canada, V6T 1Z4
| | - Kelsey L. Søndreli
- Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | | | - Jared M. LeBoldus
- Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA,Forest Engineering, Resources and Management Department, Oregon State University, Corvallis, OR 97331, USA
| | - Richard C. Hamelin
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada, VT6 1Z4,Faculté de Foresterie et Géomatique, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Canada, G1V 0A6
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6
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Li W, Wang Z, He S. Effects of species richness and nutrient availability on the invasibility of experimental microalgal microcosms. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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7
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Henderson AF, Santoro JA, Kremer P. Ensemble modeling for American chestnut distribution: Locating potential restoration sites in Pennsylvania. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.942766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The American chestnut (Castanea dentata Borkh.) was an economically, ecologically, and culturally important tree in eastern American hardwood forests. However, the American chestnut is currently functionally absent from these forests due to the introduction of an invasive fungus (Cryphonectria parasitica (Murr.) Barr) and causal agent of chestnut blight in the early 1900s. Field experiments are being carried out to develop a blight-resistant American chestnut tree, but range-wide restoration will require localized understanding of its current distribution and what factors contribute to suitable American chestnut habitat. While previous studies have researched species distribution of the American chestnut, it is important to understand how species distribution modeling (SDM) technique impacts model results. In this paper we create an ensemble model that combines multiple different SDM techniques to predict areas of suitable American chestnut habitat in Pennsylvania. Results indicate that model accuracy varied considerably by SDM technique – with artificial neural networks performing the worst (Area-Under-the-Curve, AUC = 0.705) and gradient boosting models performing the best (AUC = 0.877). Even though SDM technique accuracy varied, most models identified the same environmental variables as the most important: ratio of sand to clay in the soil, canopy cover, topographic convergence index, and topographic position index. This study offers insight into the best SDM techniques to use, as well as a method of combining SDMs for higher prediction confidence.
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8
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Sotiropoulos AG, Arango-Isaza E, Ban T, Barbieri C, Bourras S, Cowger C, Czembor PC, Ben-David R, Dinoor A, Ellwood SR, Graf J, Hatta K, Helguera M, Sánchez-Martín J, McDonald BA, Morgounov AI, Müller MC, Shamanin V, Shimizu KK, Yoshihira T, Zbinden H, Keller B, Wicker T. Global genomic analyses of wheat powdery mildew reveal association of pathogen spread with historical human migration and trade. Nat Commun 2022; 13:4315. [PMID: 35882860 PMCID: PMC9315327 DOI: 10.1038/s41467-022-31975-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 07/13/2022] [Indexed: 12/25/2022] Open
Abstract
The fungus Blumeria graminis f. sp. tritici causes wheat powdery mildew disease. Here, we study its spread and evolution by analyzing a global sample of 172 mildew genomes. Our analyses show that B.g. tritici emerged in the Fertile Crescent during wheat domestication. After it spread throughout Eurasia, colonization brought it to America, where it hybridized with unknown grass mildew species. Recent trade brought USA strains to Japan, and European strains to China. In both places, they hybridized with local ancestral strains. Thus, although mildew spreads by wind regionally, our results indicate that humans drove its global spread throughout history and that mildew rapidly evolved through hybridization. The fungus Blumeria graminis f. sp. tritici causes wheat powdery mildew disease. Here, Sotiropoulos et al. analyze a global sample of 172 mildew genomes, providing evidence that humans drove global spread of the pathogen throughout history and that mildew rapidly evolved through hybridization with local fungal strains.
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Affiliation(s)
| | - Epifanía Arango-Isaza
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Tomohiro Ban
- Kihara Institute for Biological Research, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Chiara Barbieri
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Department of Linguistic and Cultural Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, 04103, Germany
| | - Salim Bourras
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland.,Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Christina Cowger
- USDA-ARS Department of Plant Pathology, North Carolina State University, Raleigh, NC, USA
| | - Paweł C Czembor
- Plant Breeding and Acclimatization Institute - National Research Institute, Radzików, 05-870 Błonie, Poland
| | - Roi Ben-David
- Department of Vegetables and Field crops, Institute of Plant Sciences, ARO-Volcani Center, Rishon LeZion, 7528809, Israel
| | - Amos Dinoor
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food & Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Simon R Ellwood
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA, 6102, Australia
| | - Johannes Graf
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Koichi Hatta
- Hokkaido Agricultural Research Center Field Crop Research and Development, National Agricultural Research Organization, Sapporo, Hokkaido, Japan
| | - Marcelo Helguera
- Centro de Investigaciones Agropecuarias (CIAP), INTA, Córdoba, Argentina
| | - Javier Sánchez-Martín
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Bruce A McDonald
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Alexey I Morgounov
- Food and Agriculture Organization of the United Nations, Riyadh, Saudi Arabia
| | - Marion C Müller
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | | | - Kentaro K Shimizu
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Kihara Institute for Biological Research, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Taiki Yoshihira
- Department of Sustainable Agriculture, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan
| | - Helen Zbinden
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Beat Keller
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Thomas Wicker
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland.
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9
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Thierry M, Charriat F, Milazzo J, Adreit H, Ravel S, Cros-Arteil S, borron S, Sella V, Kroj T, Ioos R, Fournier E, Tharreau D, Gladieux P. Maintenance of divergent lineages of the Rice Blast Fungus Pyricularia oryzae through niche separation, loss of sex and post-mating genetic incompatibilities. PLoS Pathog 2022; 18:e1010687. [PMID: 35877779 PMCID: PMC9352207 DOI: 10.1371/journal.ppat.1010687] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 08/04/2022] [Accepted: 06/17/2022] [Indexed: 11/18/2022] Open
Abstract
Many species of fungal plant pathogens coexist as multiple lineages on the same host, but the factors underlying the origin and maintenance of population structure remain largely unknown. The rice blast fungus Pyricularia oryzae is a widespread model plant pathogen displaying population subdivision. However, most studies of natural variation in P. oryzae have been limited in genomic or geographic resolution, and host adaptation is the only factor that has been investigated extensively as a contributor to population subdivision. In an effort to complement previous studies, we analyzed genetic and phenotypic diversity in isolates of the rice blast fungus covering a broad geographical range. Using single-nucleotide polymorphism genotyping data for 886 isolates sampled from 152 sites in 51 countries, we showed that population subdivision of P. oryzae in one recombining and three clonal lineages with broad distributions persisted with deeper sampling. We also extended previous findings by showing further population subdivision of the recombining lineage into one international and three Asian clusters, and by providing evidence that the three clonal lineages of P. oryzae were found in areas with different prevailing environmental conditions, indicating niche separation. Pathogenicity tests and bioinformatic analyses using an extended set of isolates and rice varieties indicated that partial specialization to rice subgroups contributed to niche separation between lineages, and differences in repertoires of putative virulence effectors were consistent with differences in host range. Experimental crosses revealed that female sterility and early post-mating genetic incompatibilities acted as strong additional barriers to gene flow between clonal lineages. Our results demonstrate that the spread of a fungal pathogen across heterogeneous habitats and divergent populations of a crop species can lead to niche separation and reproductive isolation between distinct, widely distributed, lineages.
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Affiliation(s)
- Maud Thierry
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- CIRAD, UMR PHIM, Montpellier, France
- ANSES Plant Health Laboratory, Mycology Unit, Malzéville, France
| | - Florian Charriat
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Joëlle Milazzo
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- CIRAD, UMR PHIM, Montpellier, France
| | - Henri Adreit
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- CIRAD, UMR PHIM, Montpellier, France
| | - Sébastien Ravel
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- CIRAD, UMR PHIM, Montpellier, France
| | - Sandrine Cros-Arteil
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Sonia borron
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Violaine Sella
- ANSES Plant Health Laboratory, Mycology Unit, Malzéville, France
| | - Thomas Kroj
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Renaud Ioos
- ANSES Plant Health Laboratory, Mycology Unit, Malzéville, France
| | - Elisabeth Fournier
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Didier Tharreau
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- CIRAD, UMR PHIM, Montpellier, France
- * E-mail: (DT); (PG)
| | - Pierre Gladieux
- PHIM Plant Health Institute, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
- * E-mail: (DT); (PG)
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10
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Microsatellite Analysis Revealing High Genetic Diversity of the Chestnut Blight Fungus in South Tyrol (Northern Italy). FORESTS 2022. [DOI: 10.3390/f13020344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cryphonectria parasitica, which causes chestnut blight, is one of the most important pathogens of forest trees. In Europe, mycovirus-mediated biocontrol is the most efficient method to control the disease but can be impeded by the lack of information about the population structure of the fungus within a region. In particular, sexual reproduction and the new introduction of the pathogen can complicate biocontrol strategies. For this reason, this study aimed to determine the population structure of C. parasitica, which causes chestnut blight, in the northern Italian region of South Tyrol, using eleven multilocus microsatellite markers. Fifty-one haplotypes were found across South Tyrol, belonging to three divergent clusters. Recombinant genotypes demonstrated that sexual reproduction occurs across the different clusters. The most dominant genotypes in the region were also the most dominant in neighboring areas, such as Switzerland, northern Italy and France. All of the clusters from South Tyrol were related to the Italian genotype pool and are thought to have been introduced from northern Italian and other European populations due to naturally occurring gene flow or human-mediated introduction. At least three separate introduction events of C. parasitica might have happened in South Tyrol that could be separated by time. This study demonstrated a high genetic diversity of C. parasitica in South Tyrol and helped to shed light on the sexual reproduction and introduction events in the local populations.
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11
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Kozhar O, Kim M, Ibarra Caballero J, Klopfenstein NB, Cannon PG, Stewart JE. Long evolutionary history of an emerging fungal pathogen of diverse tree species in eastern Asia, Australia, and the Pacific Islands. Mol Ecol 2022; 31:2013-2031. [DOI: 10.1111/mec.16384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 01/27/2022] [Accepted: 01/31/2022] [Indexed: 11/27/2022]
Affiliation(s)
- Olga Kozhar
- Colorado State University Fort Collins CO USA
| | - Mee‐Sook Kim
- USDA Forest Service Pacific Northwest Research Station Corvallis OR USA
| | | | | | - Phil G. Cannon
- USDA Forest Service Forest Health Protection Vallejo CA USA
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12
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Stauber L, Croll D, Prospero S. Temporal changes in pathogen diversity in a perennial plant-pathogen-hyperparasite system. Mol Ecol 2022; 31:2073-2088. [PMID: 35122694 PMCID: PMC9540319 DOI: 10.1111/mec.16386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 01/26/2022] [Accepted: 01/31/2022] [Indexed: 11/27/2022]
Abstract
Hyperparasites can affect the evolution of pathosystems by influencing the stability of both pathogen and host populations. However, how pathogens of perennial hosts evolve in the presence of a hyperparasite has rarely been studied. Here, we investigated temporal changes in genetic diversity of the invasive chestnut blight pathogen Cryphonectria parasitica in the presence of its parasitic mycovirus Cryphonectria hypovirus 1 (CHV1). The virus reduces fungal virulence and represents an effective natural biocontrol agent against chestnut blight in Europe. We analysed genome‐wide diversity and CHV1 prevalence in C. parasitica populations in southern Switzerland that were sampled twice at an interval of about 30 years. Overall, we found that both pathogen population structure and CHV1 prevalence were retained over time. The results suggest that recent bottlenecks have influenced the structure of C. parasitica populations in southern Switzerland. Strong balancing selection signals were found at a single vegetative incompatibility (vic) locus, consistent with negative frequency‐dependent selection imposed by the vegetative incompatibility system. High levels of mating among related individuals (i.e., inbreeding) and genetic drift are probably at the origin of imbalanced allele ratios at vic loci and subsequently low vc type diversity. Virus infection rates were stable at ~30% over the study period and we found no significant impact of the virus on fungal population diversity. Consequently, the efficacy of CHV1‐mediated biocontrol was probably retained.
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Affiliation(s)
- Lea Stauber
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland.,Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Switzerland.,Department of Environmental Sciences, University of Basel, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Switzerland
| | - Simone Prospero
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
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Kupper Q, Prospero S. Microsatellite Genotyping in the Chestnut Blight Fungus Cryphonectria parasitica. Methods Mol Biol 2022; 2536:423-433. [PMID: 35819618 DOI: 10.1007/978-1-0716-2517-0_24] [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] [Indexed: 06/15/2023]
Abstract
This chapter describes the use of polymorphic microsatellite (simple sequence repeats, SSR) markers for genotyping isolates of Cryphonectria parasitica, the causal agent of chestnut blight. The SSR presented are particularly useful to characterize the genetic population structure of this invasive fungal pathogen, including invasion history (e.g., possible source population, introduced genotypes) and reproduction mode (sexual vs. asexual). Microsatellite markers can also be used to track fungal strains in laboratory and field experiments.
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Affiliation(s)
- Quirin Kupper
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
| | - Simone Prospero
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland.
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14
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Ježić M, Schwarz JM, Prospero S, Sotirovski K, Risteski M, Ćurković-Perica M, Nuskern L, Krstin L, Katanić Z, Maleničić E, Poljak I, Idžojtić M, Rigling D. Temporal and Spatial Genetic Population Structure of Cryphonectria parasitica and Its Associated Hypovirus Across an Invasive Range of Chestnut Blight in Europe. PHYTOPATHOLOGY 2021; 111:1327-1337. [PMID: 33417482 DOI: 10.1094/phyto-09-20-0405-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Chestnut blight has spread throughout Europe since the introduction of its causal agent, Cryphonectria parasitica, >70 years ago. In our study, we analyzed the diversity of vegetative compatibility (vc) and microsatellite genotypes of C. parasitica, as well as sequence diversity of Cryphonectria hypovirus 1 (CHV1) in six populations from Switzerland, Croatia, and North Macedonia. Resampling of local populations that were already investigated more than a decade ago allowed us to analyze the spatial and temporal population structure across an invasive range of the pathogen in Europe. Regardless of which genetic marker was used, the >60-year-old Swiss and Croatian populations had high population diversity, whereas more recent North Macedonian populations were mostly clonal. These diversity differences between the investigated populations remained stable over time. A high diversity of CHV1 was observed in all three countries, with North Macedonian strains forming a separate cluster from strains obtained in other countries. No correlation between vc diversity and CHV1 prevalence was observed, suggesting a well-established and maintained natural hypovirulence in all countries, further corroborated by an observed increase in genetic diversity of Croatian C. parasitica populations over time, without collapse of CHV1 prevalence.
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Affiliation(s)
- Marin Ježić
- University of Zagreb, Faculty of Science, Department of Biology, Division of Microbiology, Zagreb, Croatia
| | | | - Simone Prospero
- Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
| | - Kiril Sotirovski
- Ss Cyril and Methodius University in Skopje, Hans Em Faculty of Forest Sciences, Landscape Architecture and Environmental Engineering, 1000 Skopje, North Macedonia
| | - Mihajlo Risteski
- Ss Cyril and Methodius University in Skopje, Hans Em Faculty of Forest Sciences, Landscape Architecture and Environmental Engineering, 1000 Skopje, North Macedonia
| | - Mirna Ćurković-Perica
- University of Zagreb, Faculty of Science, Department of Biology, Division of Microbiology, Zagreb, Croatia
| | - Lucija Nuskern
- University of Zagreb, Faculty of Science, Department of Biology, Division of Microbiology, Zagreb, Croatia
| | - Ljiljana Krstin
- University J. J. Strossmayer of Osijek, Department of Biology, 31000 Osijek, Croatia
| | - Zorana Katanić
- University J. J. Strossmayer of Osijek, Department of Biology, 31000 Osijek, Croatia
| | - Ema Maleničić
- University of Zagreb, Faculty of Science, Department of Biology, Division of Microbiology, Zagreb, Croatia
| | - Igor Poljak
- University of Zagreb, Faculty of Forestry and Wood Technology, Department of Forest Genetics, Dendrology and Botany, 10000 Zagreb, Croatia
| | - Marilena Idžojtić
- University of Zagreb, Faculty of Forestry and Wood Technology, Department of Forest Genetics, Dendrology and Botany, 10000 Zagreb, Croatia
| | - Daniel Rigling
- Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
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Stauber L, Badet T, Feurtey A, Prospero S, Croll D. Emergence and diversification of a highly invasive chestnut pathogen lineage across southeastern Europe. eLife 2021; 10:e56279. [PMID: 33666552 PMCID: PMC7935491 DOI: 10.7554/elife.56279] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 02/17/2021] [Indexed: 12/18/2022] Open
Abstract
Invasive microbial species constitute a major threat to biodiversity, agricultural production and human health. Invasions are often dominated by one or a small number of genotypes, yet the underlying factors driving invasions are poorly understood. The chestnut blight fungus Cryphonectria parasitica first decimated the North American chestnut, and a more recent outbreak threatens European chestnut stands. To unravel the chestnut blight invasion of southeastern Europe, we sequenced 230 genomes of predominantly European strains. Genotypes outside of the invasion zone showed high levels of diversity with evidence for frequent and ongoing recombination. The invasive lineage emerged from the highly diverse European genotype pool rather than a secondary introduction from Asia or North America. The expansion across southeastern Europe was mostly clonal and is dominated by a single mating type, suggesting a fitness advantage of asexual reproduction. Our findings show how an intermediary, highly diverse bridgehead population gave rise to an invasive, largely clonally expanding pathogen.
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Affiliation(s)
- Lea Stauber
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL)BirmensdorfSwitzerland
- Laboratory of Evolutionary Genetics, Institute of Biology, University of NeuchâtelNeuchâtelSwitzerland
| | - Thomas Badet
- Laboratory of Evolutionary Genetics, Institute of Biology, University of NeuchâtelNeuchâtelSwitzerland
| | - Alice Feurtey
- Laboratory of Evolutionary Genetics, Institute of Biology, University of NeuchâtelNeuchâtelSwitzerland
- Plant Pathology, Institute of Integrative Biology, ETH ZürichZürichSwitzerland
| | - Simone Prospero
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL)BirmensdorfSwitzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of NeuchâtelNeuchâtelSwitzerland
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16
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Kendig AE, Spear ER, Daws SC, Flory SL, Mordecai EA. Native perennial and non-native annual grasses shape pathogen community composition and disease severity in a California grassland. THE JOURNAL OF ECOLOGY 2021; 109:900-912. [PMID: 34158675 PMCID: PMC8215988 DOI: 10.1111/1365-2745.13515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 09/23/2020] [Indexed: 06/13/2023]
Abstract
The densities of highly competent plant hosts (i.e. those that are susceptible to and successfully transmit a pathogen) may shape pathogen community composition and disease severity, altering disease risk and impacts. Life history and evolutionary history can influence host competence; longer lived species tend to be better defended than shorter lived species and pathogens adapt to infect species with which they have longer evolutionary histories. It is unclear, however, how the densities of species that differ in competence due to life and evolutionary histories affect plant pathogen community composition and disease severity.We examined foliar fungal pathogens of two host groups in a California grassland: native perennial and non-native annual grasses. We first characterized pathogen community composition and disease severity of the two host groups to approximate differences in competence. We then used observational and manipulated gradients of native perennial and non-native annual grass densities to assess the effects of each host group on pathogen community composition and disease severity in 1-m2 plots.Native perennial and non-native annual grasses hosted distinct pathogen communities but shared generalist pathogens. Native perennial grasses experienced 26% higher disease severity than non-native annuals. Only the observational gradient of native perennial grass density affected disease severity; there were no other significant relationships between host group density and either disease severity or pathogen community composition.Synthesis. The life and evolutionary histories of grasses likely influence their competence for different pathogen species, exemplified by distinct pathogen communities and differences in disease severity. However, there was limited evidence that the density of either host group affected pathogen community composition or disease severity. Therefore, competence for different pathogens likely shapes pathogen community composition and disease severity but may not interact with host density to alter disease risk and impacts at small scales.
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Affiliation(s)
- Amy E. Kendig
- Agronomy Department, University of Florida, Gainesville, FL, USA
| | - Erin R. Spear
- Smithsonian Tropical Research Institute, Panama City, Panama
| | | | - S. Luke Flory
- Agronomy Department, University of Florida, Gainesville, FL, USA
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Hessenauer P, Feau N, Gill U, Schwessinger B, Brar GS, Hamelin RC. Evolution and Adaptation of Forest and Crop Pathogens in the Anthropocene. PHYTOPATHOLOGY 2021; 111:49-67. [PMID: 33200962 DOI: 10.1094/phyto-08-20-0358-fi] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Anthropocene marks the era when human activity is making a significant impact on earth, its ecological and biogeographical systems. The domestication and intensification of agricultural and forest production systems have had a large impact on plant and tree health. Some pathogens benefitted from these human activities and have evolved and adapted in response to the expansion of crop and forest systems, resulting in global outbreaks. Global pathogen genomics data including population genomics and high-quality reference assemblies are crucial for understanding the evolution and adaptation of pathogens. Crops and forest trees have remarkably different characteristics, such as reproductive time and the level of domestication. They also have different production systems for disease management with more intensive management in crops than forest trees. By comparing and contrasting results from pathogen population genomic studies done on widely different agricultural and forest production systems, we can improve our understanding of pathogen evolution and adaptation to different selection pressures. We find that in spite of these differences, similar processes such as hybridization, host jumps, selection, specialization, and clonal expansion are shaping the pathogen populations in both crops and forest trees. We propose some solutions to reduce these impacts and lower the probability of global pathogen outbreaks so that we can envision better management strategies to sustain global food production as well as ecosystem services.
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Affiliation(s)
- Pauline Hessenauer
- Faculty of Forestry, Geography and Geomatics, Laval University, Quebec City, QC, G1V 0A6 Canada
| | - Nicolas Feau
- Faculty of Forestry, The University of British Columbia, Vancouver, BC, V6T 1Z4 Canada
| | - Upinder Gill
- College of Agriculture, Food Systems, and Natural Resources, North Dakota State University, Fargo, ND 58102, U.S.A
| | - Benjamin Schwessinger
- Research School of Biology, Australian National University, Acton, ACT 2601 Australia
| | - Gurcharn S Brar
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC, V6T 1Z4 Canada
| | - Richard C Hamelin
- Faculty of Forestry, Geography and Geomatics, Laval University, Quebec City, QC, G1V 0A6 Canada
- Faculty of Forestry, The University of British Columbia, Vancouver, BC, V6T 1Z4 Canada
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18
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Paap T, Wingfield MJ, Burgess TI, Hulbert JM, Santini A. Harmonising the fields of invasion science and forest pathology. NEOBIOTA 2020. [DOI: 10.3897/neobiota.62.52991] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Invasive alien species are widely recognised as significant drivers of global environmental change, with far reaching ecological and socio-economic impacts. The trend of continuous increases in first records, with no apparent sign of saturation, is consistent across all taxonomic groups. However, taxonomic biases exist in the extent to which invasion processes have been studied. Invasive forest pathogens have caused, and they continue to result in dramatic damage to natural forests and woody ecosystems, yet their impacts are substantially underrepresented in the invasion science literature. Conversely, most studies of forest pathogens have been undertaken in the absence of a connection to the frameworks developed and used to study biological invasions. We believe this is, in part, a consequence of the mechanistic approach of the discipline of forest pathology; one that has been inherited from the broader discipline of plant pathology. Rather than investigating the origins of, and the processes driving the arrival of invasive microorganisms, the focus of pathologists is generally to investigate specific interactions between hosts and pathogens, with an emphasis on controlling the resulting disease problems. In contrast, central to the field of invasion science, which finds its roots in ecology, is the development and testing of general concepts and frameworks. The lack of knowledge of microbial biodiversity and ecology, speciation and geographic origin present challenges in understanding invasive forest pathogens under existing frameworks, and there is a need to address this shortfall. Advances in molecular technologies such as gene and genome sequencing and metagenomics studies have increased the “visibility” of microorganisms. We consider whether these technologies are being adequately applied to address the gaps between forest pathology and invasion science. We also interrogate the extent to which the two fields stand to gain by becoming more closely linked.
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19
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Corredor‐Moreno P, Saunders DGO. Expecting the unexpected: factors influencing the emergence of fungal and oomycete plant pathogens. THE NEW PHYTOLOGIST 2020; 225:118-125. [PMID: 31225901 PMCID: PMC6916378 DOI: 10.1111/nph.16007] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 06/06/2019] [Indexed: 05/12/2023]
Abstract
In recent years, the number of emergent plant pathogens (EPPs) has grown substantially, threatening agroecosystem stability and native biodiversity. Contributing factors include, among others, shifts in biogeography, with EPP spread facilitated by the global unification of monocultures in modern agriculture, high volumes of trade in plants and plant products and an increase in sexual recombination within pathogen populations. The unpredictable nature of EPPs as they move into new territories is a situation that has led to sudden and widespread epidemics. Understanding the underlying causes of pathogen emergence is key to managing the impact of EPPs. Here, we review some factors specifically influencing the emergence of oomycete and fungal EPPs, including new introductions through anthropogenic movement, natural dispersal and weather events, as well as genetic factors linked to shifts in host range.
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20
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Hamelin RC, Roe AD. Genomic biosurveillance of forest invasive alien enemies: A story written in code. Evol Appl 2020; 13:95-115. [PMID: 31892946 PMCID: PMC6935587 DOI: 10.1111/eva.12853] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 06/30/2019] [Accepted: 07/19/2019] [Indexed: 12/15/2022] Open
Abstract
The world's forests face unprecedented threats from invasive insects and pathogens that can cause large irreversible damage to the ecosystems. This threatens the world's capacity to provide long-term fiber supply and ecosystem services that range from carbon storage, nutrient cycling, and water and air purification, to soil preservation and maintenance of wildlife habitat. Reducing the threat of forest invasive alien species requires vigilant biosurveillance, the process of gathering, integrating, interpreting, and communicating essential information about pest and pathogen threats to achieve early detection and warning and to enable better decision-making. This process is challenging due to the diversity of invasive pests and pathogens that need to be identified, the diverse pathways of introduction, and the difficulty in assessing the risk of establishment. Genomics can provide powerful new solutions to biosurveillance. The process of invasion is a story written in four chapters: transport, introduction, establishment, and spread. The series of processes that lead to a successful invasion can leave behind a DNA signature that tells the story of an invasion. This signature can help us understand the dynamic, multistep process of invasion and inform management of current and future introductions. This review describes current and future application of genomic tools and pipelines that will provide accurate identification of pests and pathogens, assign outbreak or survey samples to putative sources to identify pathways of spread, and assess risk based on traits that impact the outbreak outcome.
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Affiliation(s)
- Richard C. Hamelin
- Department of Forest and Conservation SciencesThe University of British ColumbiaVancouverBCCanada
- Institut de Biologie Intégrative et des Systèmes (IBIS)Université LavalQuébecQCCanada
- Département des sciences du bois et de la forêt, Faculté de Foresterie et GéographieUniversité LavalQuébecQCCanada
| | - Amanda D. Roe
- Great Lakes Forestry CenterNatural Resources CanadaSault Ste. MarieONCanada
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Dennert F, Meyer JB, Rigling D, Prospero S. Assessing the Phytosanitary Risk Posed by an Intraspecific Invasion of Cryphonectria parasitica in Europe. PHYTOPATHOLOGY 2019; 109:2055-2063. [PMID: 31411547 DOI: 10.1094/phyto-06-19-0197-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Intraspecific cryptic invasions may occur when new strains of an invasive species are introduced into an area where this species had already been introduced previously. In plant pathogens, such invasions are not well studied, even if, potentially, they can have severe consequences. Here, we investigated the effects of a potential intraspecific invasion in Europe of Cryphonectria parasitica, the causal agent of chestnut blight. Specifically, we tested the hypotheses that (i) non-European strains are more virulent on Castanea sativa than those already present in Europe because they have never encountered this new host, and (ii) the variation in virulence among strains is higher within native than within introduced populations. In a greenhouse, 2-year-old C. sativa seedlings were inoculated with Cryphonectria parasitica strains from South Korea, the United States, and Switzerland, and lesion development and seedling mortality were recorded weekly. Additionally, growth and sporulation of the strains were measured in vitro on agar medium at 15 and 24°C. Although lesion growth was similar for all strains, seedlings inoculated with strains from South Korea and Switzerland died faster than seedlings inoculated with strains from the United States. Moreover, in vitro strains from South Korea grew faster and produced more spores at both temperatures than the strains from the other two countries. In conclusion, our results did not support the two hypotheses. All strains, regardless of their origin, were found to be highly virulent on the inoculated chestnut seedlings. Nevertheless, current phytosanitary measures to avoid the introduction of new genotypes of C. parasitica into Europe should be further implemented.
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Affiliation(s)
- Francesca Dennert
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, CH-8903 Birmensdorf, Switzerland
| | - Joana Beatrice Meyer
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, CH-8903 Birmensdorf, Switzerland
- Forest Protection and Forest Health Section, Federal Office for the Environment FOEN, CH-3003 Bern, Switzerland
| | - Daniel Rigling
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, CH-8903 Birmensdorf, Switzerland
| | - Simone Prospero
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, CH-8903 Birmensdorf, Switzerland
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22
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Franić I, Prospero S, Hartmann M, Allan E, Auger-Rozenberg MA, Grünwald NJ, Kenis M, Roques A, Schneider S, Sniezko R, Williams W, Eschen R. Are traded forest tree seeds a potential source of nonnative pests? ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2019; 29:e01971. [PMID: 31302945 DOI: 10.1002/eap.1971] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 06/04/2019] [Accepted: 06/14/2019] [Indexed: 06/10/2023]
Abstract
The international seed trade is considered relatively safe from a phytosanitary point of view and is therefore less regulated than trade in other plants for planting. However, the pests carried by traded seeds are not well known. We assessed insects and fungi in 58 traded seed lots of 11 gymnosperm and angiosperm tree species from North America, Europe, and Asia. Insects were detected by X-raying and molecular methods. The fungal community was characterized using high-throughput sequencing (HTS) and by growing fungi on non-selective agar. About 30% of the seed lots contained insect larvae. Gymnosperms contained mostly hymenopteran (Megastigmus spp.) and dipteran (Cecidomyiidae) larvae, while angiosperms contained lepidopteran (Cydia latiferreana) and coleopteran (Curculio spp.) larvae. HTS indicated the presence of fungi in all seed lots and fungi grew on non-selective agar from 96% of the seed lots. Fungal abundance and diversity were much higher than insect diversity and abundance, especially in angiosperm seeds. Almost 50% of all fungal exact sequence variants (ESVs) found in angiosperms were potential pathogens, in comparison with around 30% of potentially pathogenic ESVs found in gymnosperms. The results of this study indicate that seeds may pose a greater risk of pest introduction than previously believed or accounted for. A rapid risk assessment suggests that only a small number of species identified in this study is of phytosanitary concern. However, more research is needed to enable better risk assessment, especially to increase knowledge about the potential for transmission of fungi to seedlings and the host range and impact of identified species.
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Affiliation(s)
- Iva Franić
- CABI, Delémont, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Simone Prospero
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Martin Hartmann
- Institute of Agricultural Sciences, ETH Zürich, Zürich, Switzerland
| | - Eric Allan
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | | | | | | | | | - Salome Schneider
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Richard Sniezko
- Dorena Genetic Resource Center, USDA Forest Service, Cottage Grove, Oregon , 97424, USA
| | - Wyatt Williams
- Private Forests Division, Oregon Department of Forestry, Salem, Oregon, 97310, USA
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Whole-genome sequencing reveals recent and frequent genetic recombination between clonal lineages of Cryphonectria parasitica in western Europe. Fungal Genet Biol 2019; 130:122-133. [DOI: 10.1016/j.fgb.2019.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 04/30/2019] [Accepted: 06/04/2019] [Indexed: 02/07/2023]
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24
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Vuković R, Liber Z, Ježić M, Sotirovski K, Ćurković-Perica M. Link between epigenetic diversity and invasive status of south-eastern European populations of phytopathogenic fungus Cryphonectria parasitica. Environ Microbiol 2019; 21:4521-4536. [PMID: 31314941 DOI: 10.1111/1462-2920.14742] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/12/2019] [Accepted: 07/15/2019] [Indexed: 12/14/2022]
Abstract
Epigenetic modifications may play an important role in invasion and adaptation of clonal and invasive populations to different environments. The aim of this study was to analyse epigenetic diversity and structure within and among populations of invasive pathogenic fungus Cryphonectria parasitica from south-eastern Europe, where one haplotype S12 dominates. The highest level of epigenetic diversity was found in haplotype S1, followed by S2, while the lowest level of epigenetic diversity was found in haplotype S12. Similar pattern of epigenetic diversity was detected in the control, genetically diverse Croatian population where S1 haplotype dominates. In four south-eastern European populations, the highest level of epigenetic diversity was observed in the Italian population, the oldest population in the studied area, while the lowest diversity was found in most recently established Bulgarian population. This relationship between epigenetic diversity and population age implies the important role of epigenetic modifications on the process of invasion. Our data suggest that epigenetic differences might affect the success of expansion of certain haplotype into new regions. Understanding the role of epigenetic processes in expansion and (pre)adaptation of fungal plant pathogens, besides fundamental knowledge, can contribute to development of strategies for control of fungal spread and pathogenesis.
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Affiliation(s)
- Rosemary Vuković
- Department of Biology, J. J. Strossmayer University of Osijek, Osijek, Croatia
| | - Zlatko Liber
- Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia.,Centre of Excellence for Biodiversity and Molecular Plant Breeding, Zagreb, Croatia
| | - Marin Ježić
- Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Kiril Sotirovski
- Faculty of Forestry, Ss. Cyril and Methodius University of Skopje, Skopje, North Macedonia
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25
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Thakur MP, van der Putten WH, Cobben MMP, van Kleunen M, Geisen S. Microbial invasions in terrestrial ecosystems. Nat Rev Microbiol 2019; 17:621-631. [DOI: 10.1038/s41579-019-0236-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2019] [Indexed: 01/08/2023]
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26
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Rocca GD, Danti R, Williams N, Eyre C, Garbelotto M. Molecular analyses indicate that both native and exotic pathogen populations serve as sources of novel outbreaks of Cypress Canker Disease. Biol Invasions 2019. [DOI: 10.1007/s10530-019-02022-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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27
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Barker BS, Cocio JE, Anderson SR, Braasch JE, Cang FA, Gillette HD, Dlugosch KM. Potential limits to the benefits of admixture during biological invasion. Mol Ecol 2018; 28:100-113. [PMID: 30485593 DOI: 10.1111/mec.14958] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Revised: 11/06/2018] [Accepted: 11/09/2018] [Indexed: 12/18/2022]
Abstract
Species introductions often bring together genetically divergent source populations, resulting in genetic admixture. This geographic reshuffling of diversity has the potential to generate favourable new genetic combinations, facilitating the establishment and invasive spread of introduced populations. Observational support for the superior performance of admixed introductions has been mixed, however, and the broad importance of admixture to invasion questioned. Under most underlying mechanisms, admixture's benefits should be expected to increase with greater divergence among and lower genetic diversity within source populations, though these effects have not been quantified in invaders. We experimentally crossed source populations differing in divergence in the invasive plant Centaurea solstitialis. Crosses resulted in many positive (heterotic) interactions, but fitness benefits declined and were ultimately negative at high source divergence, with patterns suggesting cytonuclear epistasis. We explored the literature to assess whether such negative epistatic interactions might be impeding admixture at high source population divergence. Admixed introductions reported for plants came from sources with a wide range of genetic variation, but were disproportionately absent where there was high genetic divergence among native populations. We conclude that while admixture is common in species introductions and often happens under conditions expected to be beneficial to invaders, these conditions may be constrained by predictable negative genetic interactions, potentially explaining conflicting evidence for admixture's benefits to invasion.
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Affiliation(s)
- Brittany S Barker
- University of Arizona, Tucson, Arizona.,United States Geological Survey, Boise, Idaho
| | | | | | | | | | - Heather D Gillette
- University of Arizona, Tucson, Arizona.,Northern Arizona University, Flagstaff, Arizona
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Vieira A, Silva DN, Várzea V, Paulo OS, Batista D. Novel insights on colonization routes and evolutionary potential of Colletotrichum kahawae, a severe pathogen of Coffea arabica. MOLECULAR PLANT PATHOLOGY 2018; 19:2488-2501. [PMID: 30073748 PMCID: PMC6638157 DOI: 10.1111/mpp.12726] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 05/25/2018] [Accepted: 06/28/2018] [Indexed: 05/19/2023]
Abstract
Pathogenic fungi are emerging at an increasing rate on a wide range of host plants, leading to tremendous threats to the global economy and food safety. Several plant pathogens have been considered to be invasive species, rendering large-scale population genomic analyses crucial to better understand their demographic history and evolutionary potential. Colletotrichum kahawae (Ck) is a highly aggressive and specialized pathogen, causing coffee berry disease in Arabica coffee in Africa. This pathogen leads to severe production losses and its dissemination out of Africa is greatly feared. To address this issue, a population genomic approach using thousands of single nucleotide polymorphisms (SNPs) spaced throughout the genome was used to unveil its demographic history and evolutionary potential. The current study confirms that Ck is a true clonal pathogen, perfectly adapted to green coffee berries, with three completely differentiated populations (Angolan, Cameroonian and East African). Two independent clonal lineages were found within the Angolan population as opposed to the remaining single clonal populations. The most probable colonization scenario suggests that this pathogen emerged in Angola and immediately dispersed to East Africa, where these two populations began to differentiate, followed by the introduction in Cameroon from an Angolan population. However, the differentiation between the two Angolan clonal lineages masks the mechanism for the emergence of the Cameroonian population. Our results suggest that Ck is completely differentiated from the ancestral lineage, has a low evolutionary potential and a low dispersion ability, with human transport the most likely scenario for its potential dispersion, which makes the fulfilment of the quarantine measures and management practices implemented crucial.
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Affiliation(s)
- Ana Vieira
- CIFC—Centro de Investigação das Ferrugens do CafeeiroInstituto Superior de Agronomia, Universidade de LisboaOeiras2784‐505Portugal
- CoBiG—Computational Biology and Population Genomics Group, cE3c—Centre for Ecology, Evolution and Environmental Changes, Faculdade de CiênciasUniversidade de LisboaLisboa1749‐016Portugal
- LEAF—Linking Landscape, Environment, Agriculture and FoodInstituto Superior de Agronomia, Universidade de LisboaLisboa1349‐017Portugal
| | - Diogo Nuno Silva
- CIFC—Centro de Investigação das Ferrugens do CafeeiroInstituto Superior de Agronomia, Universidade de LisboaOeiras2784‐505Portugal
- CoBiG—Computational Biology and Population Genomics Group, cE3c—Centre for Ecology, Evolution and Environmental Changes, Faculdade de CiênciasUniversidade de LisboaLisboa1749‐016Portugal
- LEAF—Linking Landscape, Environment, Agriculture and FoodInstituto Superior de Agronomia, Universidade de LisboaLisboa1349‐017Portugal
| | - Victor Várzea
- CIFC—Centro de Investigação das Ferrugens do CafeeiroInstituto Superior de Agronomia, Universidade de LisboaOeiras2784‐505Portugal
- LEAF—Linking Landscape, Environment, Agriculture and FoodInstituto Superior de Agronomia, Universidade de LisboaLisboa1349‐017Portugal
| | - Octávio Salgueiro Paulo
- CoBiG—Computational Biology and Population Genomics Group, cE3c—Centre for Ecology, Evolution and Environmental Changes, Faculdade de CiênciasUniversidade de LisboaLisboa1749‐016Portugal
| | - Dora Batista
- CIFC—Centro de Investigação das Ferrugens do CafeeiroInstituto Superior de Agronomia, Universidade de LisboaOeiras2784‐505Portugal
- CoBiG—Computational Biology and Population Genomics Group, cE3c—Centre for Ecology, Evolution and Environmental Changes, Faculdade de CiênciasUniversidade de LisboaLisboa1749‐016Portugal
- LEAF—Linking Landscape, Environment, Agriculture and FoodInstituto Superior de Agronomia, Universidade de LisboaLisboa1349‐017Portugal
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Allen JL, McKenzie SK, Sleith RS, Alter SE. First genome-wide analysis of the endangered, endemic lichen Cetradonia linearis reveals isolation by distance and strong population structure. AMERICAN JOURNAL OF BOTANY 2018; 105:1556-1567. [PMID: 30157288 DOI: 10.1002/ajb2.1150] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/14/2018] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY Lichenized fungi are evolutionarily diverse and ecologically important, but little is known about the processes that drive their diversification and genetic differentiation. Distributions are often assumed to be wholly shaped by ecological requirements rather than dispersal limitations. Furthermore, although asexual and sexual reproductive structures are observable, the lack of information about recombination rates makes inferences about reproductive strategies difficult. We investigated the population genomics of Cetradonia linearis, a federally endangered lichen in the southern Appalachians of eastern North America, to test the relative contributions of environmental and geographic distance in shaping genetic structure, and to characterize the mating system and genome-wide recombination. METHODS Whole-genome shotgun sequencing was conducted to generate data for 32 individuals of C. linearis. A reference genome was assembled, and reads from all samples were aligned to generate a set of single-nucleotide polymorphisms for further analyses. KEY RESULTS We found evidence for low rates of recombination and for isolation by distance, but not for isolation by environment. The species is putatively unisexual, given that only one mating-type locus was found. Hindcast species distribution models and the distribution of genetic diversity support C. linearis having a larger range during the Last Glacial Maximum in the southern portion of its current extent. CONCLUSIONS Our findings contribute to the understanding of factors that shape genetic diversity in C. linearis and in fungi more broadly. Because all populations are highly genetically differentiated, the extirpation of any population would mean the loss of unique genetic diversity; therefore, our results support the continued conservation of this species.
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Affiliation(s)
- Jessica L Allen
- The New York Botanical Garden, 2900 Southern Blvd., Bronx, New York, 10458, USA
- The Graduate Center, City University of New York, 365 5th Avenue, New York, New York, 10016, USA
| | - Sean K McKenzie
- Rockefeller University, 1230 York Avenue, New York, New York, 10065, USA
| | - Robin S Sleith
- The New York Botanical Garden, 2900 Southern Blvd., Bronx, New York, 10458, USA
- The Graduate Center, City University of New York, 365 5th Avenue, New York, New York, 10016, USA
| | - S Elizabeth Alter
- The Graduate Center, City University of New York, 365 5th Avenue, New York, New York, 10016, USA
- Biology Department, York College, 94-20 Guy R Brewer Blvd., Jamaica, New York, 11451, USA
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Double ML, Jarosz AM, Fulbright DW, Davelos Baines A, MacDonald WL. Evaluation of Two Decades of Cryphonectria parasitica Hypovirus Introduction in an American Chestnut Stand in Wisconsin. PHYTOPATHOLOGY 2018; 108:702-710. [PMID: 29318913 DOI: 10.1094/phyto-10-17-0354-r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Hypovirus-infected Cryphonectria parasitica strains were introduced in a large stand of American chestnut (>4,000 individuals) in western Wisconsin (USA) to evaluate whether hypoviruses can serve as biological control agents. They were deployed by treating cankers from 1992 to 1997 and again from 2004 to 2014. After 17 years of hypovirus introductions within an area of the stand with the longest history of disease, isolation of hypovirus-infected strains increased from 55% in 1994 to 86% in 2014 from cankers that were treated. During the same period, isolation from cankers that arose on trees with treated cankers increased from 29 to 72% and from 15 to 84% for cankers on nearby trees that received no treatment. Tree survivorship over the 23-year study period for trees with treated cankers was 51% compared with 31% for trees that were not treated. Introduction of hypovirus has resulted in the regrowth of the crowns of many large-diameter trees. Putative recovery of American chestnut in this stand provides evidence that prolonged hypovirus treatment can act as a biological control when limited numbers of vegetative compatibility types of C. parasitica exist.
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Affiliation(s)
- Mark L Double
- First and fifth authors: Division of Plant and Soil Sciences, West Virginia University, Morgantown 26506; second author: Departments of Plant Biology, and Plant, Soils and Microbial Sciences, and The Program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing 48824; third author: Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing 48824; and fourth author: Department of Biology, University of Wisconsin-La Crosse, La Crosse 54601
| | - Andrew M Jarosz
- First and fifth authors: Division of Plant and Soil Sciences, West Virginia University, Morgantown 26506; second author: Departments of Plant Biology, and Plant, Soils and Microbial Sciences, and The Program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing 48824; third author: Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing 48824; and fourth author: Department of Biology, University of Wisconsin-La Crosse, La Crosse 54601
| | - Dennis W Fulbright
- First and fifth authors: Division of Plant and Soil Sciences, West Virginia University, Morgantown 26506; second author: Departments of Plant Biology, and Plant, Soils and Microbial Sciences, and The Program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing 48824; third author: Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing 48824; and fourth author: Department of Biology, University of Wisconsin-La Crosse, La Crosse 54601
| | - Anita Davelos Baines
- First and fifth authors: Division of Plant and Soil Sciences, West Virginia University, Morgantown 26506; second author: Departments of Plant Biology, and Plant, Soils and Microbial Sciences, and The Program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing 48824; third author: Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing 48824; and fourth author: Department of Biology, University of Wisconsin-La Crosse, La Crosse 54601
| | - William L MacDonald
- First and fifth authors: Division of Plant and Soil Sciences, West Virginia University, Morgantown 26506; second author: Departments of Plant Biology, and Plant, Soils and Microbial Sciences, and The Program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing 48824; third author: Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing 48824; and fourth author: Department of Biology, University of Wisconsin-La Crosse, La Crosse 54601
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Introduction history and genetic diversity of the invasive ant Solenopsis geminata in the Galápagos Islands. Biol Invasions 2018. [DOI: 10.1007/s10530-018-1769-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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32
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Abstract
Bat white-nose syndrome has become associated with unparalleled mortality in bat species across the United States since 2006. In a recent article, Drees and colleagues (mBio 8:e01941-17, 2017, https://doi.org/10.1128/mBio.01941-17) utilized both whole-genome sequencing and microsatellite data to explore the origin and spread of the causative agent of bat white-nose syndrome, Pseudogymnoascus destructans. The research by Drees et al. supports the hypothesis that P. destructans was introduced into North America from Europe, with molecular dating suggesting a divergence from European isolates approximately 100 years ago. The approaches described in this study are an important contribution toward pinpointing the origins of this infection and underscore the need for more rigorous international biosecurity in order to stem the tide of emerging fungal pathogens.
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Milgroom MG, Smith ML, Drott MT, Nuss DL. Balancing selection at nonself recognition loci in the chestnut blight fungus, Cryphonectria parasitica, demonstrated by trans-species polymorphisms, positive selection, and even allele frequencies. Heredity (Edinb) 2018; 121:511-523. [PMID: 29426879 DOI: 10.1038/s41437-018-0060-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 01/12/2018] [Accepted: 01/15/2018] [Indexed: 11/09/2022] Open
Abstract
Balancing selection has been inferred in diverse organisms for nonself recognition genes, including those involved in immunity, mating compatibility, and vegetative incompatibility. Although selective forces maintaining polymorphisms are known for genes involved in immunity and mating, mechanisms of balancing selection for vegetative incompatibility genes in fungi are being debated. We hypothesized that allorecognition and its consequent inhibition of virus transmission contribute to the maintenance of polymorphisms in vegetative incompatibility loci (vic) in the chestnut blight fungus, Cryphonectria parasitica. Balancing selection was demonstrated at two loci, vic2 and vic6, by trans-species polymorphisms in C. parasitica, C. radicalis, and C. japonica and signatures of positive selection in gene sequences. In addition, more than half (31 of 54) of allele frequency estimates at six vic loci in nine field populations of C. parasitica from Asia and the eastern US were not significantly different from 0.5, as expected at equilibrium for two alleles per locus under balancing selection. At three vic loci, deviations from 0.5 were predicted based on the effects of heteroallelism on virus transmission. Twenty-five of 27 allele frequency estimates were greater than or equal to 0.5 for the allele that confers significantly stronger inhibition of virus transmission at three loci with asymmetric transmission. These results are consistent with the allorecognition hypothesis that vegetative incompatibility genes are under selection because of their role in reducing infection by viruses.
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Affiliation(s)
- Michael G Milgroom
- School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY, 14853, USA.
| | - Myron L Smith
- Department of Biology, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Milton T Drott
- School of Integrative Plant Science, Plant Pathology and Plant-Microbe Biology Section, Cornell University, Ithaca, NY, 14853, USA
| | - Donald L Nuss
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, 20850, USA.,Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV, 26506, USA
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Rigling D, Prospero S. Cryphonectria parasitica, the causal agent of chestnut blight: invasion history, population biology and disease control. MOLECULAR PLANT PATHOLOGY 2018; 19:7-20. [PMID: 28142223 PMCID: PMC6638123 DOI: 10.1111/mpp.12542] [Citation(s) in RCA: 183] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 12/19/2016] [Accepted: 01/26/2017] [Indexed: 05/25/2023]
Abstract
Chestnut blight, caused by Cryphonectria parasitica, is a devastating disease infecting American and European chestnut trees. The pathogen is native to East Asia and was spread to other continents via infected chestnut plants. This review summarizes the current state of research on this pathogen with a special emphasis on its interaction with a hyperparasitic mycovirus that acts as a biological control agent of chestnut blight. TAXONOMY Cryphonectria parasitica (Murr.) Barr. is a Sordariomycete (ascomycete) fungus in the family Cryphonectriaceae (Order Diaporthales). Closely related species that can also be found on chestnut include Cryphonectria radicalis, Cryphonectria naterciae and Cryphonectria japonica. HOST RANGE Major hosts are species in the genus Castanea (Family Fagaceae), particularly the American chestnut (C. dentata), the European chestnut (C. sativa), the Chinese chestnut (C. mollissima) and the Japanese chestnut (C. crenata). Minor incidental hosts include oaks (Quercus spp.), maples (Acer spp.), European hornbeam (Carpinus betulus) and American chinkapin (Castanea pumila). DISEASE SYMPTOMS Cryphonectria parasitica causes perennial necrotic lesions (so-called cankers) on the bark of stems and branches of susceptible host trees, eventually leading to wilting of the plant part distal to the infection. Chestnut blight cankers are characterized by the presence of mycelial fans and fruiting bodies of the pathogen. Below the canker the tree may react by producing epicormic shoots. Non-lethal, superficial or callusing cankers on susceptible host trees are usually associated with mycovirus-induced hypovirulence. DISEASE CONTROL After the introduction of C. parasitica into a new area, eradication efforts by cutting and burning the infected plants/trees have mostly failed. In Europe, the mycovirus Cryphonectria hypovirus 1 (CHV-1) acts as a successful biological control agent of chestnut blight by causing so-called hypovirulence. CHV-1 infects C. parasitica and reduces its parasitic growth and sporulation capacity. Individual cankers can be therapeutically treated with hypovirus-infected C. parasitica strains. The hypovirus may subsequently spread to untreated cankers and become established in the C. parasitica population. Hypovirulence is present in many chestnut-growing regions of Europe, either resulting naturally or after biological control treatments. In North America, disease management of chestnut blight is mainly focused on breeding with the goal to backcross the Chinese chestnut's blight resistance into the American chestnut genome.
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Affiliation(s)
- Daniel Rigling
- Swiss Federal Institute for ForestSnow and Landscape Research (WSL)Birmensdorf8903Switzerland
| | - Simone Prospero
- Swiss Federal Institute for ForestSnow and Landscape Research (WSL)Birmensdorf8903Switzerland
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Abstract
Globalization has facilitated the worldwide movement and introduction of pathogens, but epizoological reconstructions of these invasions are often hindered by limited sampling and insufficient genetic resolution among isolates. Pseudogymnoascus destructans, a fungal pathogen causing the epizootic of white-nose syndrome in North American bats, has exhibited few genetic polymorphisms in previous studies, presenting challenges for both epizoological tracking of the spread of this fungus and for determining its evolutionary history. We used single nucleotide polymorphisms (SNPs) from whole-genome sequencing and microsatellites to construct high-resolution phylogenies of P. destructans. Shallow genetic diversity and the lack of geographic structuring among North American isolates support a recent introduction followed by expansion via clonal reproduction across the epizootic zone. Moreover, the genetic relationships of isolates within North America suggest widespread mixing and long-distance movement of the fungus. Genetic diversity among isolates of P. destructans from Europe was substantially higher than in those from North America. However, genetic distance between the North American isolates and any given European isolate was similar to the distance between the individual European isolates. In contrast, the isolates we examined from Asia were highly divergent from both European and North American isolates. Although the definitive source for introduction of the North American population has not been conclusively identified, our data support the origin of the North American invasion by P. destructans from Europe rather than Asia. This phylogenetic study of the bat white-nose syndrome agent, P. destructans, uses genomics to elucidate evolutionary relationships among populations of the fungal pathogen to understand the epizoology of this biological invasion. We analyze hypervariable and abundant genetic characters (microsatellites and genomic SNPs, respectively) to reveal previously uncharacterized diversity among populations of the pathogen from North America and Eurasia. We present new evidence supporting recent introduction of the fungus to North America from a diverse Eurasian population, with limited increase in genetic variation in North America since that introduction.
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Genetic signatures of variation in population size in a native fungal pathogen after the recent massive plantation of its host tree. Heredity (Edinb) 2017; 119:402-410. [PMID: 28930289 DOI: 10.1038/hdy.2017.58] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/20/2017] [Accepted: 08/05/2017] [Indexed: 12/23/2022] Open
Abstract
Historical fluctuations in forests' distribution driven by past climate changes and anthropogenic activities can have large impacts on the demographic history of pathogens that have a long co-evolution history with these host trees. Using a population genetic approach, we investigated that hypothesis by reconstructing the demographic history of Armillaria ostoyae, one of the major pathogens of the maritime pine (Pinus pinaster), in the largest monospecific pine planted forest in Europe (south-western France). Genetic structure analyses and approximate Bayesian computation approaches revealed that a single pathogen population underwent a severe reduction in effective size (12 times lower) 1080-2080 generations ago, followed by an expansion (4 times higher) during the last 4 generations. These results are consistent with the history of the maritime pine forest in the region characterized by a strong recession during the last glaciation (~19 000 years ago) and massive plantations during the second half of the nineteenth century. Results suggest that recent and intensive plantations of a host tree population have offered the opportunity for a rapid spread and adaptation of their pathogens.
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Brusini J, Wayne ML, Franc A, Robin C. The impact of parasitism on resource allocation in a fungal host: the case of Cryphonectria parasitica and its mycovirus, Cryphonectria Hypovirus 1. Ecol Evol 2017; 7:5967-5976. [PMID: 28808558 PMCID: PMC5551080 DOI: 10.1002/ece3.3143] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 04/18/2017] [Accepted: 04/25/2017] [Indexed: 12/04/2022] Open
Abstract
Parasites are known to profoundly affect resource allocation in their host. In order to investigate the effects of Cryphonectria Hypovirus 1 (CHV1) on the life-history traits of its fungal host Cryphonectria parasitica, an infection matrix was completed with the cross-infection of six fungal isolates by six different viruses. Mycelial growth, asexual sporulation, and spore size were measured in the 36 combinations, for which horizontal and vertical transmission of the viruses was also assessed. As expected by life-history theory, a significant negative correlation was found between host somatic growth and asexual reproduction in virus-free isolates. Interestingly this trade-off was found to be positive in infected isolates, illustrating the profound changes in host resource allocation induced by CHV1 infection. A significant and positive relationship was also found in infected isolates between vertical transmission and somatic growth. This last relationship suggests that in this system, high levels of virulence could be detrimental to the vertical transmission of the parasite. Those results underscore the interest of studying host-parasite interaction within the life-history theory framework, which might permit a more accurate understanding of the nature of the modifications triggered by parasite infection on host biology.
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Affiliation(s)
- Jérémie Brusini
- Harbor Branch Oceanographic InstituteFlorida Atlantic UniversityFort PierceFLUSA
- BIOGECOINRAUniversity of BordeauxCestasFrance
- Department of BiologyUniversity of FloridaGainesvilleFLUSA
| | - Marta L. Wayne
- Department of BiologyUniversity of FloridaGainesvilleFLUSA
| | - Alain Franc
- BIOGECOINRAUniversity of BordeauxCestasFrance
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Abstract
While fungi can make positive contributions to ecosystems and agro-ecosystems, for example, in mycorrhizal associations, they can also have devastating impacts as pathogens of plants and animals. In undisturbed ecosystems, most such negative interactions will be limited through the coevolution of fungi with their hosts. In this article, we explore what happens when pathogenic fungi spread beyond their natural ecological range and become invasive on naïve hosts in new ecosystems. We will see that such invasive pathogens have been problematic to humans and their domesticated plant and animal species throughout history, and we will discuss some of the most pressing fungal threats of today.
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Depotter JRL, Seidl MF, van den Berg GCM, Thomma BPHJ, Wood TA. A distinct and genetically diverse lineage of the hybrid fungal pathogen Verticillium longisporum population causes stem striping in British oilseed rape. Environ Microbiol 2017; 19:3997-4009. [PMID: 28523726 DOI: 10.1111/1462-2920.13801] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 05/11/2017] [Accepted: 05/13/2017] [Indexed: 11/30/2022]
Abstract
Population genetic structures illustrate evolutionary trajectories of organisms adapting to differential environmental conditions. Verticillium stem striping disease on oilseed rape was mainly observed in continental Europe, but has recently emerged in the United Kingdom. The disease is caused by the hybrid fungal species Verticillium longisporum that originates from at least three separate hybridization events, yet hybrids between Verticillium progenitor species A1 and D1 are mainly responsible for Verticillium stem striping. We reveal a hitherto un-described dichotomy within V. longisporum lineage A1/D1 that correlates with the geographic distribution of the isolates with an 'A1/D1 West' and an 'A1/D1 East' cluster. Genome comparison between representatives of the A1/D1 West and East clusters excluded population distinctiveness through separate hybridization events. Remarkably, the A1/D1 West population that is genetically more diverse than the entire A1/D1 East cluster caused the sudden emergence of Verticillium stem striping in the UK, whereas in continental Europe Verticillium stem striping is predominantly caused by the more genetically uniform A1/D1 East population. The observed genetic diversity of the A1/D1 West population argues against a recent introduction of the pathogen into the UK, but rather suggests that the pathogen previously established in the UK and remained latent or unnoticed as oilseed rape pathogen until recently.
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Affiliation(s)
- Jasper R L Depotter
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands.,Department of Crops and Agronomy, National Institute of Agricultural Botany, Huntingdon Road, Cambridge, CB3 0LE, UK
| | - Michael F Seidl
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands
| | - Grardy C M van den Berg
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands
| | - Bart P H J Thomma
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands
| | - Thomas A Wood
- Department of Crops and Agronomy, National Institute of Agricultural Botany, Huntingdon Road, Cambridge, CB3 0LE, UK
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40
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Where can introduced populations learn their tricks? Searching for the geographical source of a species introduction to the Galápagos archipelago. CONSERV GENET 2017. [DOI: 10.1007/s10592-017-0988-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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43
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Robin C, Andanson A, Saint-Jean G, Fabreguettes O, Dutech C. What was old is new again: thermal adaptation within clonal lineages during range expansion in a fungal pathogen. Mol Ecol 2017; 26:1952-1963. [PMID: 28141894 DOI: 10.1111/mec.14039] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 12/27/2016] [Accepted: 01/17/2017] [Indexed: 12/25/2022]
Abstract
Range-expanding species are expected to gain an increasing importance in the context of global change. They provide a great opportunity to study contemporary evolutionary changes and to unravel the mechanisms of evolution. Cryphonectria parasitica, the causal agent of chestnut blight, originating from Asia, has been spread since the beginning of the 20th century into different continents. We took advantage of the C. parasitica recent emergence in northern France to study the changes in population genetic structure and in phenotypic traits along this colonization and climatic gradient. Four hundred twenty-seven C. parasitica isolates were sampled in 47 chestnut sites in northern France. The C. parasitica outbreak in the north was found to be due to the expansion of five dominant clonal groups from southern France and to the emergence of a few rare recombined genotypes. The evolutionary changes during C. parasitica range expansion were studied by analysing phenotypic changes in isolates from the same clonal lineage, with or without a geographic shift. Growth rates were assessed in vitro, at four temperatures. The northern isolates grew faster at 12 and 15 °C and more slowly at 28 and 32 °C than the southern isolates. These results strongly suggest local adaptation to low temperatures in C. parasitica, with a trade-off of slower growth at high temperatures. They also reflect the high evolutionary potential of C. parasitica along a colonization gradient and show that clonal evolution is not a limitation for the rapid thermal adaptation of this invasive fungal species.
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Affiliation(s)
- Cécile Robin
- BIOGECO, INRA, University of Bordeaux, 69 route d'Arcachon, 33610, Cestas, France
| | - Audrey Andanson
- BIOGECO, INRA, University of Bordeaux, 69 route d'Arcachon, 33610, Cestas, France
| | - Gilles Saint-Jean
- BIOGECO, INRA, University of Bordeaux, 69 route d'Arcachon, 33610, Cestas, France
| | - Olivier Fabreguettes
- BIOGECO, INRA, University of Bordeaux, 69 route d'Arcachon, 33610, Cestas, France
| | - Cyril Dutech
- BIOGECO, INRA, University of Bordeaux, 69 route d'Arcachon, 33610, Cestas, France
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Wang J, Fernández‐Pavía SP, Larsen MM, Garay‐Serrano E, Gregorio‐Cipriano R, Rodríguez‐Alvarado G, Grünwald NJ, Goss EM. High levels of diversity and population structure in the potato late blight pathogen at the Mexico centre of origin. Mol Ecol 2017; 26:1091-1107. [DOI: 10.1111/mec.14000] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 12/11/2016] [Accepted: 12/21/2016] [Indexed: 01/15/2023]
Affiliation(s)
- Jianan Wang
- Department of Plant Pathology and Emerging Pathogens Institute University of Florida Gainesville FL 32611 USA
| | - Sylvia P. Fernández‐Pavía
- Laboratorio de Patología Vegetal Universidad Michoacana de San Nicolás de Hidalgo IIAF Tarímbaro Michoacán 58880 México
| | | | - Edith Garay‐Serrano
- Laboratorio de Patología Vegetal Universidad Michoacana de San Nicolás de Hidalgo IIAF Tarímbaro Michoacán 58880 México
| | - Rosario Gregorio‐Cipriano
- Laboratorio de Patología Vegetal Universidad Michoacana de San Nicolás de Hidalgo IIAF Tarímbaro Michoacán 58880 México
| | - Gerardo Rodríguez‐Alvarado
- Laboratorio de Patología Vegetal Universidad Michoacana de San Nicolás de Hidalgo IIAF Tarímbaro Michoacán 58880 México
| | | | - Erica M. Goss
- Department of Plant Pathology and Emerging Pathogens Institute University of Florida Gainesville FL 32611 USA
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Kamenova S, Bartley T, Bohan D, Boutain J, Colautti R, Domaizon I, Fontaine C, Lemainque A, Le Viol I, Mollot G, Perga ME, Ravigné V, Massol F. Invasions Toolkit. ADV ECOL RES 2017. [DOI: 10.1016/bs.aecr.2016.10.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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46
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Jeger M, Bragard C, Chatzivassiliou E, Dehnen‐Schmutz K, Gilioli G, Jaques Miret JA, MacLeod A, Navajas Navarro M, Niere B, Parnell S, Potting R, Rafoss T, Urek G, Van Bruggen A, Van der Werf W, West J, Winter S, Maresi G, Prospero S, Vettraino AM, Vloutoglou I, Pautasso M, Rossi V. Risk assessment and reduction options for Cryphonectria parasitica in the EU. EFSA J 2016. [DOI: 10.2903/j.efsa.2016.4641] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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47
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Janoušek J, Wingfield MJ, Monsivais JGM, Jankovský L, Stauffer C, Konečný A, Barnes I. Genetic Analyses Suggest Separate Introductions of the Pine Pathogen Lecanosticta acicola Into Europe. PHYTOPATHOLOGY 2016; 106:1413-1425. [PMID: 26714104 DOI: 10.1094/phyto-10-15-0271-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Lecanosticta acicola is a heterothallic ascomycete that causes brown spot needle blight on native and nonnative Pinus spp. in many regions of the world. In this study we investigated the origin of European L. acicola populations and estimated the level of random mating of the pathogen in affected areas. Part of the elongation factor 1-α gene was sequenced, 11 microsatellite regions were screened, and the mating type idiomorphs were determined for 201 isolates of L. acicola collected from three continents and 17 host species. The isolates from Mexico and Guatemala were unique, highly diverse and could represent cryptic species of Lecanosticta. The isolates from East Asia formed a uniform and discrete group. Two distinct populations were identified in both North America and Europe. Approximate Bayesian computation analyses strongly suggest independent introductions of two populations from North America into Europe. Microsatellite data and mating type distributions indicated random recombination in the populations of North America and Europe. Its intercontinental introduction can most likely be explained as a consequence of the movement of infected plant material. In contrast, the spread of L. acicola within Europe appears to be primarily due to conidial dispersion and probably also ascospore dissemination.
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Affiliation(s)
- Josef Janoušek
- First and fourth authors: Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno 613 00, Czech Republic; second and seventh authors: Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa; third author: Facultad de Ciencias Forestales, UANL, Nuevo León 67700, Mexico; fifth author: Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna 1190, Austria; and sixth author: Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno 625 00, Czech Republic
| | - Michael J Wingfield
- First and fourth authors: Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno 613 00, Czech Republic; second and seventh authors: Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa; third author: Facultad de Ciencias Forestales, UANL, Nuevo León 67700, Mexico; fifth author: Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna 1190, Austria; and sixth author: Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno 625 00, Czech Republic
| | - José G Marmolejo Monsivais
- First and fourth authors: Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno 613 00, Czech Republic; second and seventh authors: Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa; third author: Facultad de Ciencias Forestales, UANL, Nuevo León 67700, Mexico; fifth author: Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna 1190, Austria; and sixth author: Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno 625 00, Czech Republic
| | - Libor Jankovský
- First and fourth authors: Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno 613 00, Czech Republic; second and seventh authors: Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa; third author: Facultad de Ciencias Forestales, UANL, Nuevo León 67700, Mexico; fifth author: Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna 1190, Austria; and sixth author: Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno 625 00, Czech Republic
| | - Christian Stauffer
- First and fourth authors: Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno 613 00, Czech Republic; second and seventh authors: Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa; third author: Facultad de Ciencias Forestales, UANL, Nuevo León 67700, Mexico; fifth author: Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna 1190, Austria; and sixth author: Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno 625 00, Czech Republic
| | - Adam Konečný
- First and fourth authors: Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno 613 00, Czech Republic; second and seventh authors: Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa; third author: Facultad de Ciencias Forestales, UANL, Nuevo León 67700, Mexico; fifth author: Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna 1190, Austria; and sixth author: Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno 625 00, Czech Republic
| | - Irene Barnes
- First and fourth authors: Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno 613 00, Czech Republic; second and seventh authors: Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa; third author: Facultad de Ciencias Forestales, UANL, Nuevo León 67700, Mexico; fifth author: Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna 1190, Austria; and sixth author: Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno 625 00, Czech Republic
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Mausse-Sitoe SND, Rodas CA, Wingfield MJ, Chen S, Roux J. Endophytic Cryphonectriaceae on native Myrtales: Possible origin of Chrysoporthe canker on plantation-grown Eucalyptus. Fungal Biol 2016; 120:827-35. [PMID: 27268243 DOI: 10.1016/j.funbio.2016.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 10/22/2022]
Abstract
Chrysoporthe austroafricana (Cryphonectriaceae) is a damaging canker pathogen on Eucalyptus species in Southern Africa. Recent studies have shown that the fungus occurs on native Syzygium species and that it has apparently undergone a host range expansion from these native trees to infect non-native Eucalyptus. The aim of this study was to consider whether Chr. austroafricana and other Cryphonectriaceae might exist as endophytes in native Myrtaceae, providing a source of inoculum to infect non-native Myrtales. Healthy branches were collected from Myrtaceae in Mozambique, incubated in florist foam, allowed to dry gradually and monitored for the appearance of fruiting bodies resembling species in the Cryphonectriaceae. Isolates were identified based on DNA sequence data. Two species in the Cryphonectriaceae were obtained, representing the first evidence that species in the Cryphonectriaceae occur as endophytes on native Myrtales, thus providing a source of inoculum to infect non-native and susceptible trees. This has important implications regarding the movement of planting stock used by ornamental tree and forestry enterprises.
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Affiliation(s)
- Silvia N D Mausse-Sitoe
- Department of Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa
| | - Carlos A Rodas
- Forestry Protection Programme, Smurfit Kappa - Colombia, Calle 15 #18-109, Puerto Isaacs, Yumbo, Valle, 760502, Colombia
| | - Michael J Wingfield
- Department of Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa
| | - ShuaiFei Chen
- Department of Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa; China Eucalypt Research Centre (CERC), Chinese Academy of Forestry (CAF), Zhanjiang, 524088, Guangdong, China
| | - Jolanda Roux
- Department of Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa.
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50
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Davy CM, Whitear AK. Feasibility and pitfalls ofex situmanagement to mitigate the effects of an environmentally persistent pathogen. Anim Conserv 2016. [DOI: 10.1111/acv.12274] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C. M. Davy
- Wildlife Preservation Canada; Guelph ON USA
- Trent University; Peterborough ON USA
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