Paraconiothyrium fuckelii, Diaporthe eres and Neocosmospora parceramosa causing cane blight of red raspberry in Northern Italy

Red raspberry (Rubus idaeus L.) represents a relevant crop which production has largely increased worldwide during the last decade. Cane blight is one of the most common diseases of red raspberry and it can produce considerable losses. During 2019-2021, surveys were conducted in red raspberry orchards in Cuneo province, Northern Italy, to investigate the etiology and pathogen diversity in association with cane blight. Eleven isolates were collected from symptomatic plants of the cultivars 'Diamond Jubilee' and 'Grandeur', and were identified through multi-locus phylogenies and morphological features. Three fungal species were identified: Paraconiothyrium fuckelii, Diaporthe eres and Neocosmospora parceramosa. Four different genomic regions were included in the molecular analyses: ITS, tef1, tub2 and rpb2. The species pathogenicity was confirmed and P. fuckelii was revealed as the most aggressive. This study provides an insight into raspberry cane blight in Italy and the genomic loci sequencing lay the basis to develop specific diagnostic protocols to monitor the presence of pathogens and to prevent disease spread, adopting effective integrated control strategies.

Automated summary

Red raspberry cane blight, a common disease causing significant losses, was investigated in orchards in Cuneo province, Northern Italy. Three pathogenic fungal species were identified, with Paraconiothyrium fuckelii being the most aggressive. Genomic loci sequencing provides a basis for specific diagnostic protocols and integrated control strategies.