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Neofusicoccum mediterraneum Is Involved in a Twig and Branch Dieback of Olive Trees Observed in Salento (Apulia, Italy)

Olive trees are infected and damaged by Botryosphaeriaceae fungi in various countries. The botryosphaeriaceous fungus Neofusicoccum mediterraneum is highly aggressive and is a major concern for olive groves in Spain and California (USA), where it causes ‘branch and twig dieback’ characterized by woo...

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Autores principales: Brunetti, Angela, Matere, Antonio, Lumia, Valentina, Pasciuta, Vittorio, Fusco, Valeria, Sansone, Domenico, Marangi, Paolo, Cristella, Nicola, Faggioli, Francesco, Scortichini, Marco, Pilotti, Massimo
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8780778/
https://www.ncbi.nlm.nih.gov/pubmed/35056001
http://dx.doi.org/10.3390/pathogens11010053
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author Brunetti, Angela
Matere, Antonio
Lumia, Valentina
Pasciuta, Vittorio
Fusco, Valeria
Sansone, Domenico
Marangi, Paolo
Cristella, Nicola
Faggioli, Francesco
Scortichini, Marco
Pilotti, Massimo
author_facet Brunetti, Angela
Matere, Antonio
Lumia, Valentina
Pasciuta, Vittorio
Fusco, Valeria
Sansone, Domenico
Marangi, Paolo
Cristella, Nicola
Faggioli, Francesco
Scortichini, Marco
Pilotti, Massimo
author_sort Brunetti, Angela
collection PubMed
description Olive trees are infected and damaged by Botryosphaeriaceae fungi in various countries. The botryosphaeriaceous fungus Neofusicoccum mediterraneum is highly aggressive and is a major concern for olive groves in Spain and California (USA), where it causes ‘branch and twig dieback’ characterized by wood discoloration, bark canker, and canopy blight. During surveys of olive groves in Apulia (southern Italy), we noticed that—in some areas—trees were heavily affected by severe branch and twig dieback. In addition, chlorosis and the appearance of red-bronze patches on the leaf preceded the wilting of the foliage, with necrotic leaves persisting on the twigs. Given the severity of the manifestation in zones also subject to olive quick decline syndrome (OQDS) caused by Xylella fastidiosa subsp. pauca, we investigated the etiology and provide indications for differentiating the symptoms from OQDS. Isolation from diseased wood samples revealed a mycete, which was morphologically and molecularly identified as N. mediterraneum. The pathogenicity tests clearly showed that this fungus is able to cause the natural symptoms. Therefore, also considering the low number of tested samples, N. mediterraneum is a potential causal agent of the observed disease. Specifically, inoculation of the twigs caused complete wilting in two to three weeks, while inoculation at the base of the stem caused severe girdling wedge-shaped cankers. The growth rate of the fungus in in vitro tests was progressively higher from 10 to 30 °C, failing to grow at higher temperatures, but keeping its viability even after prolonged exposure at 50 °C. The capacity of the isolate to produce catenulate chlamydospores, which is novel for the species, highlights the possibility of a new morphological strain within N. mediterraneum. Further investigations are ongoing to verify whether additional fungal species are involved in this symptomatology.
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spelling pubmed-87807782022-01-22 Neofusicoccum mediterraneum Is Involved in a Twig and Branch Dieback of Olive Trees Observed in Salento (Apulia, Italy) Brunetti, Angela Matere, Antonio Lumia, Valentina Pasciuta, Vittorio Fusco, Valeria Sansone, Domenico Marangi, Paolo Cristella, Nicola Faggioli, Francesco Scortichini, Marco Pilotti, Massimo Pathogens Article Olive trees are infected and damaged by Botryosphaeriaceae fungi in various countries. The botryosphaeriaceous fungus Neofusicoccum mediterraneum is highly aggressive and is a major concern for olive groves in Spain and California (USA), where it causes ‘branch and twig dieback’ characterized by wood discoloration, bark canker, and canopy blight. During surveys of olive groves in Apulia (southern Italy), we noticed that—in some areas—trees were heavily affected by severe branch and twig dieback. In addition, chlorosis and the appearance of red-bronze patches on the leaf preceded the wilting of the foliage, with necrotic leaves persisting on the twigs. Given the severity of the manifestation in zones also subject to olive quick decline syndrome (OQDS) caused by Xylella fastidiosa subsp. pauca, we investigated the etiology and provide indications for differentiating the symptoms from OQDS. Isolation from diseased wood samples revealed a mycete, which was morphologically and molecularly identified as N. mediterraneum. The pathogenicity tests clearly showed that this fungus is able to cause the natural symptoms. Therefore, also considering the low number of tested samples, N. mediterraneum is a potential causal agent of the observed disease. Specifically, inoculation of the twigs caused complete wilting in two to three weeks, while inoculation at the base of the stem caused severe girdling wedge-shaped cankers. The growth rate of the fungus in in vitro tests was progressively higher from 10 to 30 °C, failing to grow at higher temperatures, but keeping its viability even after prolonged exposure at 50 °C. The capacity of the isolate to produce catenulate chlamydospores, which is novel for the species, highlights the possibility of a new morphological strain within N. mediterraneum. Further investigations are ongoing to verify whether additional fungal species are involved in this symptomatology. MDPI 2022-01-02 /pmc/articles/PMC8780778/ /pubmed/35056001 http://dx.doi.org/10.3390/pathogens11010053 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Brunetti, Angela
Matere, Antonio
Lumia, Valentina
Pasciuta, Vittorio
Fusco, Valeria
Sansone, Domenico
Marangi, Paolo
Cristella, Nicola
Faggioli, Francesco
Scortichini, Marco
Pilotti, Massimo
Neofusicoccum mediterraneum Is Involved in a Twig and Branch Dieback of Olive Trees Observed in Salento (Apulia, Italy)
title Neofusicoccum mediterraneum Is Involved in a Twig and Branch Dieback of Olive Trees Observed in Salento (Apulia, Italy)
title_full Neofusicoccum mediterraneum Is Involved in a Twig and Branch Dieback of Olive Trees Observed in Salento (Apulia, Italy)
title_fullStr Neofusicoccum mediterraneum Is Involved in a Twig and Branch Dieback of Olive Trees Observed in Salento (Apulia, Italy)
title_full_unstemmed Neofusicoccum mediterraneum Is Involved in a Twig and Branch Dieback of Olive Trees Observed in Salento (Apulia, Italy)
title_short Neofusicoccum mediterraneum Is Involved in a Twig and Branch Dieback of Olive Trees Observed in Salento (Apulia, Italy)
title_sort neofusicoccum mediterraneum is involved in a twig and branch dieback of olive trees observed in salento (apulia, italy)
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8780778/
https://www.ncbi.nlm.nih.gov/pubmed/35056001
http://dx.doi.org/10.3390/pathogens11010053
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