European Journal of Plant Pathology (2013) 135, 323-334

Seçil Akilli, Çigdem Ulubas Serçe, Yakup Zekai Katircioglu, Salih Maden and Daniel Rigling (2013)
Characterization of hypovirulent isolates of the chestnut blight fungus, Cryphonectria parasitica from the Marmara and Black Sea regions of Turkey
European Journal of Plant Pathology 135 (2), 323-334
Abstract: Chestnut blight caused by the introduced fungus Cryphonectria parasitica has been responsible for the decline of Castanea sativa in Turkey since the 1960s. In this study, 72 C. parasitica isolates were recovered from the Marmara and Black Sea regions of Turkey showing white or cream-coloured culture morphology and were subjected to various tests to determine if they were infected by Cryphonectria hypovirus 1 (CHV-1). The vast majority of the isolates (69 out of 72) were vc type EU-1. Both mating types were found among a subsample of the isolates. The hypovirus was detected in 55 isolates by dsRNA extraction and/or virus specific RT-PCR on total RNA extracts. All but one isolates showed no or only weak phenol oxidase activity on agar medium containing tannic acid, typical of CHV-1 infected isolates. Through sequencing of a specific region of the hypovirus genome, we found that 24 hypovirus isolates belonged to the CHV-1 subtype I and six to the CHV-1 subtype F2. The distribution of the two CHV-1 subtypes in Turkey showed a clear geographic pattern. CHV-1 subtype I was only detected in the Marmara and western Black Sea region, whereas subtype F2 was restricted to the eastern part of the Black Sea region. The effectiveness of 23 hypovirulent isolates was tested against a virulent isolate on 2-3 years old chestnut sprouts. Ten hypovirulent isolates, all infected by CHV-1 subtype I, prevented canker development by more than 80 % suggesting that they might be suitable for biological control of chestnut blight in Turkey.
(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, Çigdem Ulubas Serçe, Salih Maden

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
surveys/distribution/isolation

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Pest and/or beneficial records:

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