Phytopathology (2014) 104, 918-925

Sarah Franziska Bryner, Simone Prospero and Daniel Rigling (2014)
Dynamics of Cryphonectria hypovirus infection in chestnut blight cankers
Phytopathology 104 (9), 918-925
Abstract: Virulent strains of the chestnut blight fungus Cryphonectria parasitica cause lethal bark cankers on chestnut trees. Infection of C. parasitica with Cryphonectria hypovirus 1 in Europe biologically controls this disease, leading to nonlethal and inactive cankers. Unexpectedly, virus-free C. parasitica strains have been isolated from inactive cankers. In this study, we compared the virulence of virus-infected and virus-free C. parasitica strains isolated from either inactive or active cankers on chestnut seedlings and sprouts. In the seedling experiment, we assessed canker growth and seedling mortality. In the sprout experiment, we also assessed canker growth and made fungal reisolations to determine virus infection and immigration of foreign vegetative compatibility (vc) types over a period of 13 years in a coppice forest. Overall, the virulence of virus-free C. parasitica strains isolated from inactive versus active cankers did not differ. Significant differences were only attributed to virus infection. Virus infection and fungal strain composition in cankers changed over time. Foreign vc types immigrated into cankers and virus-free cankers became virus-infected within a few years. Most of the cankers were callused over time and became inactive. However, we observed that the virus did not always persist in these cankers. This study demonstrates that virus spread occurs effectively in European chestnut forests and that this biocontrol system is highly dynamic.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Daniel Rigling

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
population dynamics/epizootiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cryphonectria parasitica	Chestnut (Castanea)
Cryphonectria parasitica hypoviruses (antagonist)	Cryphonectria parasitica	Chestnut (Castanea)