Biological control of the latent pathogen gnomoniopsis smithogylvyi in european chestnut grafting scions using bacillus amyloliquefaciens and trichoderma atroviride

Pasche, Sabrina (School of Engineering, Architecture and Landscape (hepia), HES-SO // University of Applied Sciences Western Switzerland) ; Crovadore, Julien (School of Engineering, Architecture and Landscape (hepia), HES-SO // University of Applied Sciences Western Switzerland) ; Pelleteret, Pegah (School of Engineering, Architecture and Landscape (hepia), HES-SO // University of Applied Sciences Western Switzerland) ; Jermini, Mauro (Agroscope, Cadenazzo Research Centre, Cadenazzo, Switzerland) ; Mauch-Mani, Brigitte (Laboratory of Molecular and Cell Biology, Institute of Biology, Faculty of Sciences, University of Neuchâtel, Neuchâtel, Switzerland) ; Oszako, Tomasz (Department of Forest Protection, Forest Research Institute, Sękocin Stary, Poland ; Technical University in Bialystok, Forest Faculty in Hajnówka, Poland) ; Lefort, François (School of Engineering, Architecture and Landscape (hepia), HES-SO // University of Applied Sciences Western Switzerland)

A search for endophytes in Castanea sativa Miller (Fagales: Fagaceae) grafting scions showed that a latent pathogenic fungus Gnomoniopsis smithogilvyi (Diaporthales: Gnomoniaceae) was present as the major component of the endophytic flora. Initially, the goal of this study was to develop a biological control method of Cryphonectria parasitica (Diaporthales: Valsaceae), the chestnut blight agent, by soaking chestnut scions before grafting in antagonists suspension. However, the healthy chestnut material used in in vitro and glasshouse experiments turned out to be naturally infected by a pathogen. At first view, the symptoms looked very similar to those caused by C. parasitica but some differences were noticed. DNA sequencing and application of Koch’s postulates revealed that G. smithogilvyi was the agent responsible of those symptoms. Preventive biocontrol experiments were carried out with chestnut tree scions soaked overnight in a liquid suspension of Bacillus amyloliquefaciens (Bacillales: Bacillaceae). This bacterium was then frequently found in the lower parts of scions (CF of 100% between 3.1 and 6 cm) and up to a height of 18 cm. It was observed that when B. amyloliquefaciens was present, the endophytic and opportunistic pathogenic fungus G. smithogil­vyi was not present. Conversely, the parts not colonized by the bacteria were always naturally infected by the endophytic fungus. This would indicate that the endophytic behavior of B. amyloliquefaciens inhibited the growth of G. smithogilvyi and reduced its presence in scions. A similar experiment, carried out with the Trichoderma atroviride (Hypocreales: Hypocreaceae), led to similar observations. Trichoderma atroviride was frequently isolated in the lower parts of scions (CF of 100% until 6 cm) and up to a height of 27 cm. Inoc­ulating B. amyloliquefaciens and T. atroviride as part of a preventive biocontrol treatment would allow these biological control agents to colonize the plant as endophytes and prevent the development of G. smithogilvyi.


Keywords:
Article Type:
scientifique
Faculty:
Ingénierie et Architecture
School:
HEPIA - Genève
Institute:
inTNE - Institut Terre-Nature-Environnement
Date:
2016-06
Pagination:
10 p.
Published in:
Dendrobiology
Numeration (vol. no.):
2016, vol. 75, pp. 113-122
DOI:
ISSN:
1641-1307
Appears in Collection:

Note: The status of this file is: restricted


 Record created 2020-08-14, last modified 2020-10-27

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