1. |
- Cleary, Michelle, et al.
(author)
-
Global Geographic Distribution and Host Range of Fusarium circinatum, the Causal Agent of Pine Pitch Canker
- 2020
-
In: Forests. - : MDPI AG. - 1999-4907. ; 11
-
Research review (peer-reviewed)abstract
- Fusarium circinatum, the causal agent of pine pitch canker (PPC), is currently one of the most important threats ofPinusspp. globally. This pathogen is known in many pine-growing regions, including natural and planted forests, and can affect all life stages of trees, from emerging seedlings to mature trees. Despite the importance of PPC, the global distribution ofF. circinatumis poorly documented, and this problem is also true of the hosts within countries that are affected. The aim of this study was to review the global distribution ofF. circinatum, with a particular focus on Europe. We considered (1) the current and historical pathogen records, both positive and negative, based on confirmed reports from Europe and globally; (2) the genetic diversity and population structure of the pathogen; (3) the current distribution of PPC in Europe, comparing published models of predicted disease distribution; and (4) host susceptibility by reviewing literature and generating a comprehensive list of known hosts for the fungus. These data were collated from 41 countries and used to compile a specially constructed geo-database. A review of 6297 observation records showed thatF. circinatumand the symptoms it causes on conifers occurred in 14 countries, including four in Europe, and is absent in 28 countries. Field observations and experimental data from 138 host species revealed 106 susceptible host species including 85Pinusspecies, 6 non-pine tree species and 15 grass and herb species. Our data confirm that susceptibility toF. circinatumvaries between different host species, tree ages and environmental characteristics. Knowledge on the geographic distribution, host range and the relative susceptibility of different hosts is essential for disease management, mitigation and containment strategies. The findings reported in this review will support countries that are currently free ofF. circinatumin implementing effective procedures and restrictions and prevent further spread of the pathogen.
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2. |
- Cleary, Michelle, et al.
(author)
-
Potential Interactions between Invasive Fusarium circinatum and Other Pine Pathogens in Europe
- 2020
-
In: Forests. - : MDPI AG. - 1999-4907. ; 11
-
Research review (peer-reviewed)abstract
- Pines are major components of native forests and plantations in Europe, where they have both economic significance and an important ecological role. Diseases of pines are mainly caused by fungal and oomycete pathogens, and can significantly reduce the survival, vigor, and yield of both individual trees and entire stands or plantations. Pine pitch canker (PPC), caused by Fusarium circinatum (Nirenberg and O'Donnell), is among the most devastating pine diseases in the world, and is an example of an emergent invasive disease in Europe. The effects of microbial interactions on plant health, as well as the possible roles plant microbiomes may have in disease expression, have been the focus of several recent studies. Here, we describe the possible effects of co-infection with pathogenic fungi and oomycetes with F. circinatum on the health of pine seedlings and mature plants, in an attempt to expand our understanding of the role that biotic interactions may play in the future of PPC disease in European nurseries and forests. The available information on pine pathogens that are able to co-occur with F. circinatum in Europe is here reviewed and interpreted to theoretically predict the effects of such co-occurrences on pine survival, growth, and yield. Beside the awareness that F. circinatum may co-occurr on pines with other pathogens, an additional outcome from this review is an updating of the literature, including the so-called grey literature, to document the geographical distribution of the relevant pathogens and to facilitate differential diagnoses, particularly in nurseries, where some of them may cause symptoms similar to those induced by F. circinatum. An early and accurate diagnosis of F. circinatum, a pathogen that has been recently introduced and that is currently regulated in Europe, is essential to prevent its introduction and spread in plantings and forests.
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3. |
- Cleary, Michelle, et al.
(author)
-
The increasing threat to European forests from the invasive foliar pine pathogen, Lecanosticta acicola
- 2023
-
In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 536
-
Journal article (peer-reviewed)abstract
- European forests are threatened by increasing numbers of invasive pests and pathogens. Over the past century, Lecanosticta acicola, a foliar pathogen predominantly of Pinus spp., has expanded its range globally, and is increasing in impact. Lecanosticta acicola causes brown spot needle blight, resulting in premature defoliation, reduced growth, and mortality in some hosts. Originating from southern regions of North American, it devastated forests in the USA's southern states in the early twentieth century, and in 1942 was discovered in Spain.Derived from Euphresco project 'Brownspotrisk,' this study aimed to establish the current distribution of Lecanosticta species, and assess the risks of L. acicola to European forests. Pathogen reports from the literature, and new/ unpublished survey data were combined into an open-access geo-database (http://www.portaloff orestpathology.com), and used to visualise the pathogen's range, infer its climatic tolerance, and update its host range. Lecanosticta species have now been recorded in 44 countries, mostly in the northern hemisphere. The type species, L. acicola, has increased its range in recent years, and is present in 24 out of the 26 European countries where data were available. Other species of Lecanosticta are largely restricted to Mexico and Central America, and recently Colombia.The geo-database records demonstrate that L. acicola tolerates a wide range of climates across the northern hemisphere, and indicate its potential to colonise Pinus spp. forests across large swathes of the Europe. Pre-liminary analyses suggest L. acicola could affect 62% of global Pinus species area by the end of this century, under climate change predictions.Although its host range appears slightly narrower than the similar Dothistroma species, Lecanosticta species were recorded on 70 host taxa, mostly Pinus spp., but including, Cedrus and Picea spp. Twenty-three, including species of critical ecological, environmental and economic significance in Europe, are highly susceptible to L. acicola, suffering heavy defoliation and sometimes mortality. Variation in apparent susceptibility between reports could reflect variation between regions in the hosts' genetic make-up, but could also reflect the signif-icant variation in L. acicola populations and lineages found across Europe. This study served to highlight sig-nificant gaps in our understanding of the pathogen's behaviour.Lecanosticta acicola has recently been downgraded from an A1 quarantine pest to a regulated non quarantine pathogen, and is now widely distributed across Europe. With a need to consider disease management, this study also explored global BSNB strategies, and used Case Studies to summarise the tactics employed to date in Europe.
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4. |
- Davydenko, Kateryna
(author)
-
A Comparative Study of the Pathogenicity of Fusarium circinatum and other Fusarium Species in Polish Provenances of P-sylvestris L.
- 2018
-
In: Forests. - : MDPI AG. - 1999-4907. ; 9
-
Journal article (peer-reviewed)abstract
- The fungal pathogen Fusarium circinatum is the causal agent of Pine Pitch Canker (PPC), a disease which seriously affects different species of pine in forests and nurseries worldwide. In Europe, the fungus affects pines in northern Spain and Portugal, and it has also been detected in France and Italy. Here, we report the findings of the first trial investigating the susceptibility of Polish provenances of Scots pine, Pinus sylvestris L., to infection by F. circinatum. In a greenhouse experiment, 16 Polish provenances of Scots pine were artificially inoculated with F. circinatum and with six other Fusarium species known to infect pine seedlings in nurseries. All pines proved highly susceptible to PPC and displayed different levels of susceptibility to the other Fusarium spp. tested. The findings obtained indicate the potentially strong threat of establishment of an invasive pathogen such as F. circinatum following unintentional introduction into Poland.
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5. |
- Davydenko, Kateryna
(author)
-
An Overview of Mycorrhiza in Pines: Research, Species, and Applications
- 2024
-
In: Plants. - 2223-7747. ; 13
-
Research review (peer-reviewed)abstract
- In the latest literature, climate models show that the conditions for pines, spruces, larches, and birches will deteriorate significantly. In Poland, as well as in other European countries, there are already signs of the decline of these species. This review article deals with the symbiotic relationships between fungi and plants, which can hardly be overestimated, using the example of pine trees. These are the oldest known symbiotic relationships, which are of great benefit to both components and can help plants, in particular, survive periods of severe drought and the attack of pathogens on the roots. This article describes symbioses and their causal conditions, as well as the mycorrhizal components of pine trees and their properties; characterizes ectomycorrhizal fungi and their mushroom-forming properties; and provides examples of the cultivation of pure fungal cultures, with particular attention to the specificity of the mycorrhizal structure and its effects on the growth and development of Pinus species. Finally, the role of mycorrhiza in plant protection and pathogen control is described.
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6. |
- Davydenko, Kateryna, et al.
(author)
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Dothistroma Needle Blight on High Altitude Pine Forests in Montenegro
- 2017
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In: Baltic Forestry. - 1392-1355. ; 23, s. 294-302
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Journal article (peer-reviewed)abstract
- Dothistroma needle blight (DNB) is one of the most serious and widespread needle diseases of pines. Its current distribution was investigated in high altitude native and planted pine forests in Montenegro. The suitability for the disease under different climatic conditions is discussed. Using molecular methods, polymerase chain reaction (PCR) with species specific primers, Dothistroma septosporum (Dorog) M. Morelet was detected from needles of Pinus nigra Arn., Pinus nigra 'Dalmatica' (Visiani) Franco, Pinus sylvestris L., Pinus mugo Turra, Pinus heldreichii H. Christ, Pinus peuce Griseb. and Picea abies Karst. in different parts of Montenegro, at altitudes between 800 and 2150 m. Dothistroma pini Hulbary was detected from P. sylvestris, P. nigra and P. mugo from restricted area in Northwestern part of Montenegro at altitudes between 800 and 1850 m. This is the first report of DNB on P. mugo and P. abies in Montenegro, and the first time that D. septosporum was detected from P. nigra 'Dalmatica'. Also, D. septosporum was detected through native forests of P. heldreichii and P. peuce. The climatic conditions and altitudes where DNB was detected were different from what has previously been reported for this region. From this study, we can conclude that DNB is present in high-altitude pine forests throughout Montenegro. However, the intensity of the disease is low due to prevailing environmental conditions, which are probably not favorable for DNB development.
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7. |
- Davydenko, Kateryna, et al.
(author)
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Forewarned is forearmed: harmonized approaches for early detection of potentially invasive pests and pathogens in sentinel plantings
- 2019
-
In: NeoBiota. - : Pensoft Publishers. - 1619-0033 .- 1314-2488. ; , s. 95-123
-
Journal article (peer-reviewed)abstract
- The number of invasive alien pest and pathogen species affecting ecosystem functioning, human health and economies has increased dramatically over the last decades. Discoveries of invasive pests and pathogens previously unknown to science or with unknown host associations yet damaging on novel hosts highlights the necessity of developing novel tools to predict their appearance in hitherto naive environments. The use of sentinel plant systems is a promising tool to improve the detection of pests and pathogens before introduction and to provide valuable information for the development of preventative measures to minimize economic or environmental impacts. Though sentinel plantings have been established and studied during the last decade, there still remains a great need for guidance on which tools and protocols to put into practice in order to make assessments accurate and reliable. The sampling and diagnostic protocols chosen should enable as much information as possible about potential damaging agents and species identification. Consistency and comparison of results are based on the adoption of common procedures for sampling design and sample processing. In this paper, we suggest harmonized procedures that should be used in sentinel planting surveys for effective sampling and identification of potential pests and pathogens. We also review the benefits and limitations of various diagnostic methods for early detection in sentinel systems, and the feasibility of the results obtained supporting National Plant Protection Organizations in pest and commodity risk analysis.
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8. |
- Davydenko, Kateryna, et al.
(author)
-
Fraxinus excelsior seed is not a probable introduction pathway for Hymenoscyphus fraxineus
- 2018
-
In: Forest Pathology. - : Wiley. - 1437-4781 .- 1439-0329. ; 48
-
Journal article (peer-reviewed)abstract
- We investigated the transmission of Hymenoscyphus fraxineus from infested seed to germinating seedlings of common ash (Fraxinus excelsior) in order to determine the potential risk associated with intra- and intercontinental movement of seed. Neither fungal isolations from necrotic or healthy embryos nor PCR testing with H.fraxineus-specific primers detected the pathogen. Similarly, H.fraxineus was not detected in axenically grown seedlings generated from infested seed lots. The results help clear up prior confusion of the pathogen being seed-borne. Any remaining surface contamination by pathogen spores could be washed off seeds as a quarantine measure.
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9. |
- Davydenko, Kateryna, et al.
(author)
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Fungal Communities Vectored by Ips sexdentatus in Declining Pinus sylvestris in Ukraine: Focus on Occurrence and Pathogenicity of Ophiostomatoid Species
- 2021
-
In: Insects. - : MDPI AG. - 2075-4450. ; 12
-
Journal article (peer-reviewed)abstract
- Simple Summary Bark beetles serve as vectors to numerous tree pathogens, the most conspicuous guild of which are ophiostomatoid fungi. Most of these fungi are known to cause blue-stain discoloration of wood, and some of them are pathogenic to trees, in certain cases able to kill them. Over the last years, drought-induced stress and attacks by bark beetle Ips sexdentatus resulted in a massive dieback of Pinus sylvestris in Ukraine. Limited and fragmented knowledge is available as to which ophiostomatoid fungi in this geographic area are vectored by Ips sexdentatus, and their roles in tree dieback. It is known, though, that in different parts of Europe those fungal communities might significantly differ. This study represents the first and so far, the most extensive analysis of fungal associates of I. sexdentatus in eastern Europe accomplished combining different methods, using insect, plant, and fungal material, and reports a number of previously unknown insect-vectored pathogens of P. sylvestris. Increasing climate change-related disturbances to forests put reported findings in a broader geographical context. Drought-induced stress and attacks by bark beetle Ips sexdentatus currently result in a massive dieback of Pinus sylvestris in eastern Ukraine. Limited and fragmented knowledge is available on fungi vectored by the beetle and their roles in tree dieback. The aim was to investigate the fungal community vectored by I. sexdentatus and to test the pathogenicity of potentially aggressive species to P. sylvestris. Analysis of the fungal community was accomplished by combining different methods using insect, plant, and fungal material. The material consisted of 576 beetles and 96 infested wood samples collected from six sample plots within a 300 km radius in eastern Ukraine and subjected to fungal isolations and (beetles only) direct sequencing of ITS rDNA. Pathogenicity tests were undertaken by artificially inoculating three-to-four-year-old pine saplings with fungi. For the vector test, pine logs were exposed to pre-inoculated beetles. In all, 56 fungal taxa were detected, 8 exclusively by isolation, and 13 exclusively by direct sequencing. Those included nine ophiostomatoids, five of which are newly reported as I. sexdentatus associates. Two ophiostomatoid fungi, which exhibited the highest pathogenicity, causing 100% dieback and mortality, represented genera Graphium and Leptographium. Exposure of logs to beetles resulted in ophiostomatoid infections. In conclusion, the study revealed numerous I. sexdentatus-vectored fungi, several of which include aggressive tree pathogens.
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10. |
- Davydenko, Kateryna, et al.
(author)
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Fungi associated with Ips acuminatus (Coleoptera: Curculionidae) in Ukraine with a special emphasis on pathogenicity of ophiostomatoid species
- 2017
-
In: European Journal of Entomology. - : Biology Centre, AS CR. - 1802-8829 .- 1210-5759. ; 114, s. 77-85
-
Journal article (peer-reviewed)abstract
- Conifer bark beetles are well known to be associated with fungal complexes, which consist of pathogenic ophiostomatoid fungi as well as obligate saprotroph species. However, there is little information on fungi associated with Ips acuminatus in central and eastern Europe. The aim of the study was to investigate the composition of the fungal communities associated with the pine engraver beetle, I. acuminatus, in the forest-steppe zone in Ukraine and to evaluate the pathogenicity of six associated ophiostomatoid species by inoculating three-year-old Scots pine seedlings with these fungi. In total, 384 adult beetles were collected from under the bark of declining and dead Scots pine trees at two different sites. Fungal culturing from 192 beetles resulted in 447 cultures and direct sequencing of ITS rRNA from 192 beetles in 496 high-quality sequences. Identification of the above revealed that the overall fungal community was composed of 60 species. Among these, the most common were Entomocorticium sp. (24.5%), Diplodia pinea (24.0%), Ophiostoma ips (16.7%), Sydowia polyspora (15.1%), Graphilbum cf rectangulosporium (15.1%), Ophiostoma minus (13.8%) and Cladosporium pini-ponderosae (13.0%). Pathogenicity tests were done using six species of ophiostomatoid fungi, which were inoculated into Scots pine seedlings. All ophiostomatoid fungi tested successfully infected seedlings of Scots pine with varying degrees of virulence. Ophiostoma minus was the only fungus that caused dieback in inoculated seedlings. It is concluded that I. acuminatus vectors a species-rich fungal community including pathogens such as D. pinea and O. minus. The fungal community reported in the present study is different from that reported in other regions of Europe. Pathogenicity tests showed that O. minus was the most virulent causing dieback in seedlings of Scots pine, while other fungi tested appeared to be only slightly pathogenic or completely non-pathogenic.
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11. |
- Davydenko, Kateryna, et al.
(author)
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Fungi associated with the red-haired bark beetle, Hylurgus ligniperda (Coleoptera: Curculionidae) in the forest-steppe zone in eastern Ukraine
- 2014
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In: European Journal of Entomology. - : Biology Centre, AS CR. - 1210-5759 .- 1802-8829. ; 111, s. 561-565
-
Journal article (peer-reviewed)abstract
- The aim of this study was to investigate the composition of the fungal community associated with the red-haired bark beetle (Hylurgus ligniperda Fabricius) in two plantations of Pinus sylvestris L. located in the Kharkiv and Luhansk regions (ca. 250 km apart) in the forest-steppe zone in eastern Ukraine. In each plantation, 48 beetles were collected from butts of living trees and 48 beetles from stems of fallen trees, i.e., a total of 96. Half of the beetles from each site were used for culturing fungi and the other half for direct sequencing the internal transcribed spacer of fungal ribosomal RNA (ITS rRNA). Thirty distinct fungal taxa were identified by culturing and 31 by direct sequencing. When pooled, there were 40 fungal taxa among which Ophiostoma piceae (Munch) Sydow & P. Sydow (10.3%), Alternaria alternata (Fries) Keissler (9.7%), Ogataea neopini Nagatsuka, S. Saito & Sugiyama (8.0%), Botryotinia fuckeliana (de Bary) Whetzel (5.1%), Cladosporium sp. Link (5.1%) and Sydowia polyspora (Brefeld & Tavel) E. Muller (4.6%) were the most common. Species of the genus Ophiostoma were the most abundant and included five different taxa O. piceae, O. bicolor R.W. Davidson & D.E. Wells, O. ips (Rumbold) Nannfeldt, O. canum (Muller) Sydow & P. Sydow and O. rectangulosporium Ohtaka, Masuya & Yamaoka, all of which are known to be at most weak pathogens of trees. The plant pathogen Botryotinia fuckeliana and insect pathogens Isaria farinose (Holmskjold) Fries and Beauveria bassiana (Balsamo-Crivelli) Vuillemin were also detected. Basidiomycetes were rare, among which three wood-decaying fungi Bjerkandera adusta (Willdenow) P. Karsten, Fomitopsis pinicola (Swartz) P. Karsten and Heterobasidion annosum (Fries) Brefeld were detected. In conclusion, in the forest-steppe zone in eastern Ukraine H. ligniperda is a vector of diverse communities of fungi the majority of which, if at all, are only weak pathogens of trees.
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12. |
- Davydenko, Kateryna, et al.
(author)
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Fungi in foliage and shoots of Fraxinus excelsior in eastern Ukraine: a first report on Hymenoscyphus pseudoalbidus
- 2013
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In: Forest Pathology. - : Wiley. - 1437-4781 .- 1439-0329. ; 43, s. 462-467
-
Journal article (peer-reviewed)abstract
- In eastern Ukraine, the first symptoms of dieback on common ash (Fraxinus excelsior) were observed in 2010, as sparse flushing of leaves, bark necrosis and wood discoloration of shoots. The aim of this study was to assess possible causal agents of the damage by studying fungal communities in both symptomatic and healthy-looking shoots, and leaf petioles. Field sampling was carried out in 2010 in Kharkiv and Sumy regions in eastern Ukraine and included 68 segments of symptomatic shoots, 68 segments of healthy-looking shoots and 240 segments of petioles. DNA isolation from individual segments and direct sequencing of fungal ITS rRNA resulted in 430 fungal sequences representing 29 distinct taxa. Results showed that Hymenoscyphus pseudoalbidus - the primary causal agent of ash dieback in Europe - was present at low proportion (5.6%) in symptomatic shoots. Other more frequently detected fungi were Epicoccum nigrum, Venturia fraxini, Colletotrichum truncatum, Aureobasidium pullulans, Alternaria alternata, Alternaria sp. and Lophiostoma corticola. In conclusion, the study reports on the first incidence of ash decline in the Ukraine and other possible causal agents of damage which may help to evaluate and forecast the future situation with F.excelsior stands in the region.
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13. |
- Davydenko, Kateryna, et al.
(author)
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Invasion of Emerald Ash Borer Agrilus planipennis and Ash Dieback Pathogen Hymenoscyphus fraxineus in Ukraine-A Concerted Action
- 2022
-
In: Forests. - : MDPI AG. - 1999-4907. ; 13
-
Journal article (peer-reviewed)abstract
- Emerald Ash Borer (EAB), Agrilus planipennis, is a beetle that originates from East Asia. Upon invasion to North America in the early 2000s, it killed untold millions of ash trees. In European Russia, EAB was first detected in Moscow in 2003 and proved to have the potential to also kill native European ash (Fraxinus excelsior). The beetle has since spread in all geographic directions, establishing itself in eastern Ukraine by 2019 and possessing potential for further westward spread towards the EU. Apart from the approaching EAB, F. excelsior is currently threatened by the dieback disease (ADB) caused by the invasive ascomycete fungus Hymenoscyphus fraxineus. The infestation by EAB combined with ADB infection is expected to be more lethal than either of them alone, yet the potential consequences are unknown. To date, eastern Ukraine represents the geographic area in which both invasions overlap, thus providing the opportunity for related investigations. The aims of the study were to investigate: (i) the EAB expansion range in Ukraine, (ii) the relative susceptibility of F. excelsior and American ash (Fraxinus pennsylvanica) to EAB and ADB, and (iii) the combined effect/impact on ash condition imposed by both the pest and disease in the area subjected to the invasion. The results have demonstrated that (i) the invasion of EAB is currently expanding both in terms of newly infested trees and invaded geographic area; (ii) F. excelsior is more resistant to EAB than F. pennsylvanica, while F. excelsior is more susceptible to ADB than F. pennsylvanica; and (iii) the infection by ADB is likely to predispose F. excelsior to the infestation by EAB. It was concluded that inventory and mapping of surviving F. excelsior, affected by both ADB and EAB, is necessary to acquire genetic resources for the work on strategic, long-term restoration of F. excelsior in devastated areas, thereby tackling a possible invasion of EAB to the EU.
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14. |
- Davydenko, Kateryna, et al.
(author)
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Looking for relationships between the populations of Dothistroma septosporum in northern Europe and Asia
- 2018
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In: Fungal Genetics and Biology. - : Elsevier BV. - 1087-1845 .- 1096-0937. ; 110, s. 15-25
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Journal article (peer-reviewed)abstract
- Dothistroma septosporum, a notorious pine needle pathogen with an unknown historical geographic origin and poorly known distribution pathways, is nowadays found almost in all areas inhabited by pines (Pinus spp.). The main aim of this study was to determine the relationship between North European and East Asian populations. In total, 238 Eurasian D. septosporum isolates from 11 countries, including 211 isolates from northern Europe, 16 isolates from Russian Far East and 11 isolates from Bhutan were analysed using 11 species-specific microsatellite and mating type markers. The most diverse populations were found in northern Europe, including the Baltic countries, Finland and European Russia. Notably, D. septosporum has not caused heavy damage to P. sylvestris in northern Europe, which may suggest a long co-existence of the host and the pathogen. No indication was obtained that the Russian Far East or Bhutan could be the indigenous area of D. septosporum, as the genetic diversity of the fungus there was low and evidence suggests gene flow from northern Europe to Russian Far East. On the western coast of Norway, a unique genetic pattern was observed, which differed from haplotypes dominating other Fennoscandian populations. As an agent of dothistroma needle blight, only D. septosporum was documented in northern Europe and Asia, while D. pini was found in Ukraine and Serbia.
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15. |
- Davydenko, Kateryna
(author)
-
Occurrence and pathogenicity of tree-pathogenic fungi vectored by bark beetles
- 2021
-
Doctoral thesis (other academic/artistic)abstract
- Fungal pathogens associated with bark beetles represent one of the most significant problems to forest health. Among these fungi, ophiostomatoid group are known to be most commonly associated with bark beetles. Some of these pathogens, such as Dutch elm disease-causing fungi, have a very long history of extensive research, while fungi causing other diseases are poorly or only partially understood and substantial knowledge gaps can exist in their ecology and spread.The aims of the studies were to provide new knowledge on indigenous and newly massively tree-devastating bark beetles, vectored communities of fungi, and their pathogenicity to host trees. The principal methods included fungal culturing and rDNA sequencing, which allowed the investigation of composition of fungal communities associated with bark beetles. In particular, both ophiostomatoid and other phytopathogenic fungi were the most commonly detected groups. The use of pathogenicity tests revealed the ability of different ophiostomatoid fungi to infect Pinus sylvestris saplings, but with a varying degree of success for different fungal species. Long-term trials carried out in Sweden showed that Scolytus multistriatus is a vector for Dutch elm disease caused by invasive Ophiostoma ulmi complex that recently invaded the island of Gotland causing the disease to Ulmus minor.It can be concluded that i) bark beetles are vectors for different fungi and that ophiostomatoid fungi are the most closely associated symbionts; ii) bark beetles can vector different functional groups of fungi including aggressive pathogens; iii) highly virulent fungi can help bark beetles to overcome the tree defence. The work presented in this thesis demonstrates that some fungi associated with bark beetles may significantly contribute to tree mortality. Understanding the nature of fungal-insect interactions may help more effectively to manage potential threats.
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16. |
- Davydenko, Kateryna
(author)
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Potential Westward Spread of Emerald Ash Borer, Agrilus planipennis Fairmaire, 1888 (Coleoptera: Buprestidae) from Eastern Ukraine
- 2023
-
In: Forests. - 1999-4907. ; 14
-
Journal article (peer-reviewed)abstract
- Emerald ash borer (EAB), Agrilus planipennis, is a phloem-boring beetle, native to East Asia that has become a serious invasive pest of ash (Fraxinus spp.) trees in North America and European Russia since the early 2000s. In 2019, EAB was detected in Ukraine. It had spread over 300 km from the entry point over two years and killed hundreds of Fraxinus excelsior and F. pennsylvanica trees. EAB poses a threat to the ash forests of neighboring European countries, which have already been damaged by the invasive fungus Hymenoscyphus fraxineus. The purpose of this research was (i) to reveal the traits of EAB and the climatic variables that affect its survival; (ii) to predict the EAB expansion range in Ukraine and westward; and (iii) to compare the most significant bioclimatic variables in the native, invasive ranges of EAB, as well as outside these ranges. The results demonstrated the following: (i) in all ranges, EAB has adapted to the seasonal temperature variations; (ii) the MaxEnt model predicted the potential distribution of EAB with high accuracy (AUC = 0.988); the predicted area of EAB invasion covered 87%, 48%, and 32% in Luhansk, Kharkiv, and Donetsk regions, respectively; and (iii) the ranges of climatic variables in EAB-inhabited regions demonstrated the high ecological plasticity of this pest. However, the predictions could be improved by considering forest structure, as well as the localization of roads.
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17. |
- Davydenko, Kateryna
(author)
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The Situation and Perspectives of European Ash (Fraxinus excelsior) in Ukraine: Focus on Eastern Border
- 2019
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In: Baltic Forestry. - 1392-1355. ; 25, s. 193-202
-
Journal article (peer-reviewed)abstract
- The health condition of European ash (Fraxinus excelsior) stands in Ukraine has become worse since 2006. An alien invasive pathogenic fungus Hymenoscyphus fraxineus was firstly identified in 2011 in the eastern part of the country and subsequently, its presence had been confirmed in the western and central parts. The aims of our research were to evaluate the forest health of ash trees and identify the main causes of ash decline in different regions of Ukraine with emphasis on ash dieback and its association with collar rots.Results showed that since 2013 the number of trees with ash dieback symptoms has been gradually increasing, reaching up to 92 % in 2018. Total mortality due to ash dieback was up to 9 % in 2018. Disease intensity remains high in the north and central Ukraine comparing with the east. Branch dieback, collar rots, epicormic shoots and bacterial disease of ash were more often in the eastern region, some symptoms were observed simultaneously. Ash bark beetle galleries, as well as foliage browsing insects, were found mostly in weakened and/or dying trees.It was indicated that collar rots significantly increase the mortality of ash trees. Armillaria spp. fungi were found to be frequently associated with ash dieback on living stems and fallen trees in 2017, causing high rates of mortality in the northern and central regions. For further ash conservation and breeding programs, resistant trees in severely damaged regions should be selected to preserve genetic diversity in ash populations.
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18. |
- Davydenko, Kateryna
(author)
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Variability in Pine Pitch Canker Susceptibility among Scots Pine (Pinus sylvestris) Provenances in Eastern Europe
- 2024
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In: Forests. - 1999-4907. ; 15
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Journal article (peer-reviewed)abstract
- Pine pitch canker, caused by the ascomycete Fusarium circinatum, poses a substantial threat to pine trees and Douglas firs (Pseudotsuga menziesii), and has been identified as a pervasive issue in forests and nurseries worldwide, particularly in regions where susceptible conifers are cultivated. Given its prevalence in the Iberian Peninsula, assessments of the susceptibility of diverse European provenances of Scots pine (Pinus sylvestris)-specifically those from Poland, Lithuania, and Ukraine-have been conducted. Preliminary evaluations of Polish provenances have raised concerns about the potential threat to Scots pine stands in Poland posed by pitch canker. Under controlled conditions, we examined the impact of F. circinatum inoculation on the survival of seeds and seedlings from ten provenances of Scots pine. In response, the initial assessment of F. circinatum pathogenicity was undertaken in a controlled greenhouse environment. This evaluation uncovered a heightened susceptibility of pine seedlings to pitch canker among the tested provenances. Notably, one Lithuanian provenance demonstrated superior resistance to pitch canker, while two Polish provenances exhibited a higher prevalence of symptomless seedlings. These findings underscore the need for further exploration and identification of resilient individuals within these provenances, offering valuable insights for developing strategies to mitigate the impact of pitch canker on Scots pine in Europe.
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19. |
- Davydenko, Kateryna
(author)
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Worldwide Genetic Structure Elucidates the Eurasian Origin and Invasion Pathways of Dothistroma septosporum, Causal Agent of Dothistroma Needle Blight
- 2021
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In: Journal of Fungi. - : MDPI AG. - 2309-608X. ; 7
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Journal article (peer-reviewed)abstract
- Dothistroma septosporum, the primary causal agent of Dothistroma needle blight, is one of the most significant foliar pathogens of pine worldwide. Its wide host and environmental ranges have led to its global success as a pathogen and severe economic damage to pine forests in many regions. This comprehensive global population study elucidated the historical migration pathways of the pathogen to reveal the Eurasian origin of the fungus. When over 3800 isolates were examined, three major population clusters were revealed: North America, Western Europe, and Eastern Europe, with distinct subclusters in the highly diverse Eastern European cluster. Modeling of historical scenarios using approximate Bayesian computation revealed the North American cluster was derived from an ancestral population in Eurasia. The Northeastern European subcluster was shown to be ancestral to all other European clusters and subclusters. The Turkish subcluster diverged first, followed by the Central European subcluster, then the Western European cluster, which has subsequently spread to much of the Southern Hemisphere. All clusters and subclusters contained both mating-types of the fungus, indicating the potential for sexual reproduction, although asexual reproduction remained the primary mode of reproduction. The study strongly suggests the native range of D. septosporum to be in Eastern Europe (i.e., the Baltic and Western Russia) and Western Asia.
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20. |
- Elfstrand, Malin, et al.
(author)
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Comparative analyses of the Hymenoscyphus fraxineus and Hymenoscyphus albidus genomes reveals potentially adaptive differences in secondary metabolite and transposable element repertoires
- 2021
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In: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 22
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Journal article (peer-reviewed)abstract
- Background The dieback epidemic decimating common ash (Fraxinus excelsior) in Europe is caused by the invasive fungus Hymenoscyphus fraxineus. In this study we analyzed the genomes of H. fraxineus and H. albidus, its native but, now essentially displaced, non-pathogenic sister species, and compared them with several other members of Helotiales. The focus of the analyses was to identify signals in the genome that may explain the rapid establishment of H. fraxineus and displacement of H. albidus. Results The genomes of H. fraxineus and H. albidus showed a high level of synteny and identity. The assembly of H. fraxineus is 13 Mb longer than that of H. albidus', most of this difference can be attributed to higher dispersed repeat content (i.e. transposable elements [TEs]) in H. fraxineus. In general, TE families in H. fraxineus showed more signals of repeat-induced point mutations (RIP) than in H. albidus, especially in Long-terminal repeat (LTR)/Copia and LTR/Gypsy elements. Comparing gene family expansions and 1:1 orthologs, relatively few genes show signs of positive selection between species. However, several of those did appeared to be associated with secondary metabolite genes families, including gene families containing two of the genes in the H. fraxineus-specific, hymenosetin biosynthetic gene cluster (BGC). Conclusion The genomes of H. fraxineus and H. albidus show a high degree of synteny, and are rich in both TEs and BGCs, but the genomic signatures also indicated that H. albidus may be less well equipped to adapt and maintain its ecological niche in a rapidly changing environment.
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21. |
- Franic, Iva, et al.
(author)
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Climate, host and geography shape insect and fungal communities of trees
- 2023
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In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 13:1
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Journal article (peer-reviewed)abstract
- Non-native pests, climate change, and their interactions are likely to alter relationships between trees and tree-associated organisms with consequences for forest health. To understand and predict such changes, factors structuring tree-associated communities need to be determined. Here, we analysed the data consisting of records of insects and fungi collected from dormant twigs from 155 tree species at 51 botanical gardens or arboreta in 32 countries. Generalized dissimilarity models revealed similar relative importance of studied climatic, host-related and geographic factors on differences in tree-associated communities. Mean annual temperature, phylogenetic distance between hosts and geographic distance between locations were the major drivers of dissimilarities. The increasing importance of high temperatures on differences in studied communities indicate that climate change could affect tree-associated organisms directly and indirectly through host range shifts. Insect and fungal communities were more similar between closely related vs. distant hosts suggesting that host range shifts may facilitate the emergence of new pests. Moreover, dissimilarities among tree-associated communities increased with geographic distance indicating that human-mediated transport may serve as a pathway of the introductions of new pests. The results of this study highlight the need to limit the establishment of tree pests and increase the resilience of forest ecosystems to changes in climate.
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22. |
- Franic, Iva, et al.
(author)
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Worldwide diversity of endophytic fungi and insects associated with dormant tree twigs
- 2022
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In: Scientific Data. - : Nature Publishing Group. - 2052-4463. ; 9:1
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Journal article (peer-reviewed)abstract
- International trade in plants and climate change are two of the main factors causing damaging tree pests (i.e. fungi and insects) to spread into new areas. To mitigate these risks, a large-scale assessment of tree-associated fungi and insects is needed. We present records of endophytic fungi and insects in twigs of 17 angiosperm and gymnosperm genera, from 51 locations in 32 countries worldwide. Endophytic fungi were characterized by high-throughput sequencing of 352 samples from 145 tree species in 28 countries. Insects were reared from 227 samples of 109 tree species in 18 countries and sorted into taxonomic orders and feeding guilds. Herbivorous insects were grouped into morphospecies and were identified using molecular and morphological approaches. This dataset reveals the diversity of tree-associated taxa, as it contains 12,721 fungal Amplicon Sequence Variants and 208 herbivorous insect morphospecies, sampled across broad geographic and climatic gradients and for many tree species. This dataset will facilitate applied and fundamental studies on the distribution of fungal endophytes and insects in trees.
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23. |
- Marciulyniene, Diana, et al.
(author)
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Can pruning help maintain vitality of ash trees affected by ash dieback in urban landscapes?
- 2017
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In: Urban Forestry & Urban Greening. - : Elsevier BV. - 1618-8667 .- 1610-8167. ; 27, s. 69-75
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Journal article (peer-reviewed)abstract
- Hymenoscyphus fraxineus causes a destructive invasive tree disease known as ash dieback threatening the survival of common ash not only in the forests, but also in urban and landscape settings. Pruning is a potential management practice that could help maintain tree vitality and aesthetics in parks, gardens, alleys and recreation areas, as well as maintaining veteran trees having high heritage or cultural value, or trees with high genetic importance (e.g. located in clonal seed orchards). In this study we investigated the maximum distance proximal to the lesion margin at which H. fraxineus can be detected on individual branches infected by the fungus in order to provide recommendations for pruning. Pruning of branches was carried out on 38 trees in southern Sweden. Tissue samples including bark and wood were collected from the margin of the lesion and at 5 cm intervals proximal to the lesion. Molecular analysis revealed presence of H. fraxineus in 91.3% of the investigated lesions. The proportion of lesions at which H. fraxineus could be detected declined with increasing distance from the lesion margin, with a significant reduction in the number of positive samples at 10 cm proximal to the margin. At 30 cm from the lesion edge the pathogen was never detected. Our results suggest that routine pruning may help maintain the vitality of younger trees. Pruning branches at least 35 cm from visible, active lesions in the bark should exclude the fungus and therefore reduce the probability of stem infection by H. fraxineus, however this cultural control tactic may only be economically feasible for high value amenity trees.
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24. |
- Menkis, Audrius, et al.
(author)
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Identifying Fraxinus excelsior tolerant to ash dieback: Visual field monitoring versus a molecular marker
- 2020
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In: Forest Pathology. - : Wiley. - 1437-4781 .- 1439-0329. ; 50
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Journal article (peer-reviewed)abstract
- Ash dieback (ADB) caused by the pathogen Hymenoscyphus fraxineus is the cause of massive mortality of Fraxinus spp. in Europe. The aim of this work was to check for the presence of the molecular marker for ADB tolerance in mapped healthy-looking F. excelsior trees, and to compare its occurrence in trees exhibiting severe ADB symptoms. Monitoring of 135 healthy-looking F. excelsior on the island of Gotland, Sweden, showed that after 3-4 years 99.3% of these trees had 0%-10% crown damage, thus remaining in a similar health condition as when first mapped. After 5-6 years, 94.7% of these trees had 0%-10% crown damage. Molecular analysis of leaf tissues from 40 of those showed the presence of the molecular marker in 34 (85.0%) trees, while it was absent in 6 (15.0%) trees. Analysis of leaf tissues from 40 severely ADB-diseased trees showed the presence of the molecular marker in 17 (42.5%) trees, but its absence in 23 (57.5%) trees (p < .0001). The results demonstrated that monitoring of healthy-looking F. excelsior is a simple and straightforward approach for the selection of presumably ADB-tolerant ash for future breeding. The cDNA-based molecular marker revealed moderate capacity on its own to discriminate between presumably ADB-tolerant and susceptible F. excelsior genotypes.
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25. |
- Menkis, Audrius, et al.
(author)
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Scolytus multistriatus associated with Dutch elm disease on the island of Gotland: phenology and communities of vectored fungi
- 2016
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In: Mycological Progress. - : Springer Science and Business Media LLC. - 1617-416X .- 1861-8952. ; 15
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Journal article (peer-reviewed)abstract
- Scolytus multistriatus Marsham, the smaller European elm bark beetle, is a vector for Dutch elm disease (DED) that in the year 2005 invaded the island of Gotland (Sweden). The island possesses the largest population of elm (mainly Ulmus minor Mill.) in northern Europe. The aim of this study was to monitor flying periods of S. multistriatus during three consecutive years and by using high-throughput sequencing to assess communities of vectored fungi. Sampling of the beetles was carried out at two different sites in Gotland in 2012, 2013, and 2014. In total, 50 pheromone traps were placed at each site and checked weekly during June-August each year. From all sites and years, 177 beetles were trapped. Among these, 6.2 % were trapped in June, 76.8 % in July, and 16.9 % in August (difference significant at p<0.007). Sequencing of ITS rDNA from the beetles revealed the presence of 1589 fungal taxa, among which virulent DED pathogen Ophiostoma novo-ulmi Brasier was the second most common species (9.0 % of all fungal sequences). O. ulmi Buisman, the less virulent DED pathogen, was also detected but only in a single beetle, which was sampled in 2012 (0.04 % of sequences). There were 13.0 % of the beetles infested with O. novo-ulmi in 2012, 4.0% in 2013, and 27.7% in 2014. O. novo-ulmi comprised 0.8% of fungal sequences in 2012, 0.002 % in 2013, and 8.2 % in 2014. The study showed that the proportion of S. multistriatus vectoring O. novo-ulmi has increased in recent years.
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