Phytopathologia Mediterranea (2015) 54, 465-476

Lucio Montecchio, Genny Fanchin, Valeria Berton and Linda Scattolin (2015)
Vegetative incompatibility and potential involvement of a mycovirus in the Italian population of Geosmithia morbida
Phytopathologia Mediterranea 54 (3), 465-476
Abstract: Studies carried out during an Italian outbreak of the Thousand Cankers Disease of walnut, demonstrated that non-coalescing cankers on host plants, separated by equidistant uninfected zones, were associated with incompatible strains of Geosmithia morbida. Confirmation of the vegetative incompatibility of paired fungal isolates, randomly collected from black walnuts, was obtained from observations of a clear separation zones and the absence of anastomoses. Pairing tests with two incompatible monoconidial strains indicated differences in morphology and growth rates. Electron microscopy revealed the presence of icosahedral mycovirus-like particles in one of the monoconidial strains that demonstrated low degrees of virulence in planta compared with a particlefree monoconidial strain. The occurrence of a vegetative incompatibility system in recently introduced populations of G. morbida has considerable implications for fungal biology. Incompatibility in G. morbida and potential direct or indirect roles of the observed virus-like particles have potential ecological and epidemiological consequences.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Lucio Montecchio

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Geosmithia morbida	Walnut/butternut (Juglans)	Italy