<i>Gnomoniopsis smithogilvyi</i> , the causal agent of chestnut brown rot reported from Portugal

To ensure fruit quality and promote good storage practices, it is important to identify the fungi associated with chestnut (Castanea sativa) nut rots. In 2018, in Trás-os-Montes region of Portugal, five orchards were selected 300 fruits collected from ground by hand during harvest period. laboratory, observed visually number decayed nuts recorded. Morphological symptoms evaluated diseased help a scalpel, sections (2 × 2 mm) an infected cotyledon cut for fungal isolation. Sections dipped 70% (v/v) ethanol minutes placed 90 mm diameter Petri dishes containing potato dextrose agar (PDA; 39 g/l) allow mycelial growth. Plates incubated at 25±2°C seven days dark. Single colonies transferred new PDA plates obtain purified isolates subsequent identification. Identification was initially based on morphological characteristics species identification obtained molecular methods. DNA extraction performed using REDExtract-N-Amp™ Plant PCR Kit (Sigma-Aldrich, USA), ITS amplified universal primers ITS1 ITS4 (White et al., 1990). The sequencing Stabvida Laboratories (Caparica, Portugal). Sequences compared published sequences GenBank databases BLAST. Gnomoniopsis smithogilvyi isolated which had cotyledons whitish-brown colour (Fig. 1). On PDA, mycelium G. woolly greyish developed concentric circles 2). This found 0 4.3% studied (Table Isolates Samil4.1, Samil6.1 Brg-16 preserved slopes kept 4°C collection Instituto Politécnico de Bragança. Accession Nos. these are MN956833, MN960397 MN960408. identified industrial processing plant 2017, 2018 2019 proportion 8.0, 5.3 5.0% respectively. These values line study conducted Driss (2019) samples Portugal where 6.4% affected smithogilvyi. first detection Portugal. has been reported as main or among major endophytes tree (Visentin 2012) rotten several countries Europe Asia, Australia (Lione 2019). disease alteration texture degradation sometimes kernels dehydrated Several attacks can affect production (Vannini 2017). authors grateful Project BioChestnut - IPM Implement effective control strategies against almond diseases under Programme PDR2020-101-030959 financial support.