Incidence of mycoviruses in epidemic and post-epidemic populations of the ash dieback pathogen Chalara fraxinea and evaluation of their potential for biological control of the disease“ (CONTROLDIEBACK)
Projects leader: dr. Vaidotas Lygis
Project partners: Nature Research Centre (the Leading Party, Vilnius, Lithuania) and Swiss Federal Institute for Forest, Snow and Landscape Research WSL (Swiss Partner, Birmensdorf, Switzerland)
Leader of the Swiss team: dr. Daniel Rigling, head of the research group Phytopathology
Project duration: 2012-11-01 – 2016-04-30
Project budget: 627 106,00 EUR (758 414,00 CHF)
The causal agent of mass ash dieback in Europe, relatively recently identified invasive pathogenic fungus ascomycete Chalara fraxinea (teleomorph – Hymenoscyphus fraxineus; former name – H. pseudoalbidus) was most likely introduced to Europe from eastern Asia. The disease was first recorded in mid 1990’s in eastern Poland and Lithuania and has since then spread across the continent. The dieback has already been recorded in more than 30 European countries, including Russia. So far, no effective control measures have been developed against the devastating disease, and proper management strategies for the diseased trees and stands remain unclear. The agent of the ash dieback was for the first time described by a famous Polish forest pathologist professor T. Kowalski in 2006 (as C. fraxinea).
Common ash (Fraxinus excelsior), a tree species the most susceptible to H. fraxineus, is already getting endangered in certain regions of Europe: for example, in Sweden, where ash was previously commercially important for timber production, it is now a Red-Listed species.
ABOUT THE PROJECT
In Europe, the dieback of common ash lasts already for two decades (in Lithuania – for more than 15 years), however no effective means to control this devastating disease have been offered so far, and the perspectives for growing ash are obscure. Today, ash stands in Lithuania and neighbouring countries experience a post-epidemic chronic dieback with only a small fraction of asymptomatic trees. In Switzerland, the disease was first reported in 2008 in the north-western part of the country, from where it expanded rapidly to other regions. In many regions of Switzerland an epidemic disease phase is currently observed (spread of the disease is progressing slower in alpine regions due to natural physical barriers).
Options for management of this novel forest disease are currently very limited and mainly directed to search for resistance in the host tree. Mycoviruses are commonly found in all major groups of plant pathogenic fungi. Some of these viruses were found to cause debilitating disease or reduce virulence in its fungal host, and thereby have the potential to be used as biological control agents.
Aiming to create and test novel control means of the ash dieback, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) together with partners from the Nature Research Centre (Vilnius, Lithuania) have initiated a collaborative research project „CONTROLDIEBACK“.
The main aim of the initiated project – to characterize epidemic (Swiss) and post-epidemic (Lithuanian) populations of the ash dieback pathogen H. fraxineus in respect to virulence, genetic diversity and occurrence of mycoviruses, and to assess biological control potential of the identified mycoviruses against the disease.
- to investigate genetic diversity and virulence of H. fraxineus isolates originating from Lithuanian (post-epidemic) and Swiss (epidemic) populations;
- to screen H. fraxineus for mycoviruses using a metagenomic approach based on next generation sequencing;
- to characterize the detected mycoviruses and to determine virus incidence in epidemic and post-epidemic populations of the pathogen;
- to investigate impact of the identified mycoviruses on their host H. fraxineus thus evaluating their biocontrol potential;
- to organize project publicity measures and to disseminate achieved results to the public and scientific society.
- Genetic structure of Lithuanian and Swiss H. fraxineus populations revealed
- Assessed virulence of H. fraxineus isolates from Lithuanian and Swiss populations
- Mycoviruses detected in H. fraxineus isolates
- Assessment of incidence of the mitovirus HfMV1 in epidemic and post-epidemic populations of H. fraxineus
- Assessment of phenotypic effects of the mitovirus HfMV1 on its fungal host H. fraxineus
Publicity of the achieved results (more)
An informative article (in a form of an interview) published in a Swiss newspaper „az Limmattaler Zeitung“
Missions implemented under the ‘CONTROLDIEBACK’ project (more)
Dr. Daiva Burokienė during her apprenticeship at project Partner‘s institute (WSL, Birmensdorf, Switzerland): investigation of the genetic diversity of Hymenoscyphus fraxineus populations
The current study is financially supported by Lithuanian-Swiss cooperation programme to reduce economic and social disparities within the enlarged European Union, project grant agreement No. CH-3-ŠMM-01/12.