Plant Disease (2019) 103, 430-438

Joana Beatrice Meyer, Loïc Chalmandrier, Fabio Fässler, Christopher Schefer, Daniel Rigling and Simone Prospero (2019)
Role of fresh dead wood in the epidemiology and the biological control of the chestnut blight fungus
Plant Disease 103 (3), 430-438
Abstract: The invasive fungus Cryphonectria parasitica, the causal agent of chestnut blight, is able to survive and sporulate on the bark of fresh dead Castanea sativa wood for at least 2 years. Here, we experimentally investigated the role of fresh dead wood in the epidemiology of chestnut blight, specifically in the spread of the hyperparasitic virus Cryphonectria hypovirus 1, which acts as biocontrol agent of C. parasitica. A total of 152 artificially initiated, virulent bark cankers in four chestnut stands were treated with virus-infected asexual spores originating either from sporulating dead wood or from a spore suspension. Molecular markers for both the virus and the fungal carrier were used to examine the spread of the applied biocontrol virus. Fourteen months after treatment, 42 to 76% of the conidial spray-treated cankers and 50 to 60% of the cankers exposed to a sporulating dead stem had been virus infected by the applied hypovirulent conidia in all four study sites. Virus infection reduced canker expansion and promoted canker healing (callusing). Thus, fresh chestnut dead wood may play an important role in supporting the successful spread of natural hypovirulence in chestnut forests. Further, combined with the application of virus-infected conidial suspensions, it may help promote the establishment of artificially released hypoviruses in chestnut stands to control chestnut blight.
(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
population dynamics/ epidemiology
Research topic(s) for beneficials or antagonists:
population dynamics/epizootiology
transmission/dispersal

---

Pest and/or beneficial records:

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