<abstract xmlns="http://www.w3.org/1999/xhtml"><p> The mortality of a young elm Ulmus minor in 2014 in Geneva prompted a search for the microorganisms potentially involved. Symptoms included foliar chlorosis and wilting followed by defoliation of branches. Wood symptoms included a brown streaking of sap wood and brown stains in trunk and branches. The comparison of the resulting ITS rDNA sequences to the NCBI Nucleotide database allowed to identify 10 different organisms. The genus Geosmithia represented 48% of the isolates belonging to three species: Geosmithia langdonii (7 isolates) and 2 unknown morphologically and genetically different Geosmithia sp. 1 and sp. 2 (4 isolates). Geosmithia species are very little known ascomycetes, which have been recently shown to be opportunistic pathogens on broadleaved trees and conifers, living as saprobes in galleries of many bark beetle species. In the case described here, Geosmithia langdonii, and the unknown Geosmithia species were found in symptomatic wood while bark beetle galleries were found in close regions of the symptomatic wood. Geosmithia langdonii was the major fungus retrieved from the symptomatic wood and could have contributed, along with other identified fungal species, to a pathogenic complex producing symptoms similar to the ones of the Dutch Elm Disease and led to the dieback of this elm tree. Geosmithia langdonii and 2 yet unknown Geosmithia species (sp. 1 and sp. 2), different from any other reported Geosmithia species are reported from an elm tree in Switzerland for the first time.</p></abstract>

The mortality of a young elm Ulmus minor in 2014 in Geneva prompted a search for the microorganisms potentially involved. Symptoms included foliar chlorosis and wilting followed by defoliation of branches. Wood symptoms included a brown streaking of sap wood and brown stains in trunk and branches. The comparison of the resulting ITS rDNA sequences to the NCBI Nucleotide database allowed to identify 10 different organisms. The genus Geosmithia represented 48% of the isolates belonging to three species: Geosmithia langdonii (7 isolates) and 2 unknown morphologically and genetically different Geosmithia sp. 1 and sp. 2 (4 isolates). Geosmithia species are very little known ascomycetes, which have been recently shown to be opportunistic pathogens on broadleaved trees and conifers, living as saprobes in galleries of many bark beetle species. In the case described here, Geosmithia langdonii, and the unknown Geosmithia species were found in symptomatic wood while bark beetle galleries were found in close regions of the symptomatic wood. Geosmithia langdonii was the major fungus retrieved from the symptomatic wood and could have contributed, along with other identified fungal species, to a pathogenic complex producing symptoms similar to the ones of the Dutch Elm Disease and led to the dieback of this elm tree. Geosmithia langdonii and 2 yet unknown Geosmithia species (sp. 1 and sp. 2), different from any other reported Geosmithia species are reported from an elm tree in Switzerland for the first time.

First report of Geosmithia langdonii and Geosmithia spp. isolated from a decaying elm (Ulmus minor) in Geneva, Switzerland

University of Applied Sciences and Arts Western Switzerland, Geneva Institute for Technology Architecture and Landscape, Institute Land Nature and Environment, Plants and Pathogens Group, 50 route de Presinge, 1254 Jussy, Switzerland

Folia Forestalia Polonica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

The mortality of a young elm Ulmus minor in 2014 in Geneva prompted a search for the microorganisms potentially involved. Symptoms included foliar chlorosis...

First report of Geosmithia langdonii and Geosmithia spp. isolated from a decaying elm (Ulmus minor) in Geneva, Switzerland

Published Online: Jul 14, 2016

Page range: 96 - 102

Received: Apr 13, 2016

Accepted: Apr 20, 2016

DOI: https://doi.org/10.1515/ffp-2016-0011

Keywords
Dutch elm disease Geosmithia langdonii, Geosmithia spp., elm, Ulmus minor, endophytes

© 2016

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

First report of Geosmithia langdonii and Geosmithia spp. isolated from a decaying elm (Ulmus minor) in Geneva, Switzerland

Published Online: Jul 14, 2016

Page range: 96 - 102

Received: Apr 13, 2016

Accepted: Apr 20, 2016

DOI: https://doi.org/10.1515/ffp-2016-0011

KeywordsDutch elm disease Geosmithia langdonii, Geosmithia spp., elm, Ulmus minor, endophytes

© 2016

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
Dutch elm disease Geosmithia langdonii, Geosmithia spp., elm, Ulmus minor, endophytes