Sphaceloma coryli: A Reemerging Pathogen Causing Heavy Losses on Hazelnut in Southern Italy

Area of Science:

• Plant Pathology
• Mycology
• Agricultural Science

Background:

• A novel disease caused severe crop losses in Italian hazelnut orchards between 2013-2014.
• Symptoms included leaf, bract, and shell necrosis, premature fruit drop, and aborted nuts.

Purpose of the Study:

• To identify the causal agent of the disease affecting hazelnut crops.
• To characterize the fungus, including its sexual stage and pathogenicity.
• To evaluate in vitro the efficacy of fungicides against the pathogen.

Main Methods:

• Fungal isolation and morphological identification as Sphaceloma coryli.
• Artificial inoculation of healthy hazelnut plants to confirm pathogenicity.
• Microscopic observation and phylogenetic analysis (ITS sequences) to identify the teleomorph.
• In vitro studies on germination, mycelial growth, and fungicide sensitivity.

Main Results:

• Sphaceloma coryli was consistently isolated from diseased tissues.
• Artificial inoculation successfully reproduced the observed disease symptoms.
• The teleomorph was identified as a new species, Elsinoë coryli, described for the first time.
• Optimal growth conditions and fungicide sensitivity were determined in vitro.

Conclusions:

• Elsinoë coryli is the causal agent of the new hazelnut disease in Italy.
• The identification and characterization of its teleomorph provide crucial information for disease management.
• In vitro fungicide evaluations offer preliminary data for developing control strategies against this emerging hazelnut disease.