Abstract

Hazelnut (Corylus avellana L.) trees in Chile are affected by different fungi that cause cankers and wood necrosis. However, available information on the species of fungi that cause this problem is scarce. In the 2019/20 season, a study was conducted to identify the species of pathogens causing wood damage in European hazelnut. Twenty branches showing cankers or symptoms of wood necrosis were obtained from 26 different orchards located from the Maule to the Araucania regions of Chile. Wood pieces were taken from the zone of necrosis, disinfected and placed in PDA medium supplemented with streptomycin sulfate for fungal isolation and morphological identification. In addition, molecular analyses of the ITS, TEF-1α and β-tub regions of 12 commonly isolated fungi were performed. Species of Diaporthe genus were isolated frequently (20.8% of the 520 samples analyzed), with Diaporthe ambigua being the most commom species. Fusarium spp. and Diplodia mutila, which are pathogenic in hazelnut, represented 5.3 and 3.6%, of isolations, respectively. Species of Alternaria and Sordaria fimicola, which are undescribed as pathogen of hazelnut, were recovered in 19% of isolations. The presence of saprophytes such as Epicoccum nigrum, species of Aspergillus, Cladosporium, Trichoderma, Entoleuca and Rhizopus did not exceed 4%. Diaporthaceae isolates occurred in orchards in Maule and Araucanía, while Diplodia isolates were observed in orchards located in Maule, Ñuble, and Biobío regions. ‘Tonda di Giffoni’ was affected by the greatest diversity of fungal species. These results suggest that further research is required to evaluate the effectiveness of fungicides to control the species identified in hazelnut, such as Diaporthe ambigua, Diplodia mutila, and Fusarium species.