وقوع بیماری لکه سیاه میوه انار ناشی از قارچ Cytospora punicaeدر استان مازندران

During the inspection conducted in the fall of 2023, symptoms including black spots were observed on pomegranate fruits in Sari city, Mazandaran province. Fragments of infected samples were cultured on Potato Dextrose Agar (PDA) medium after routine disinfection. Three days later, white fungal colonies were visible around the samples. The isolates were visible in dark brown color after purification and growth in PDA culture medium in 28oC. Morphological considering such as the color of the colony and the shape of the produced conidia, the isolates showed a substantial similarity to the Cytospora genus. The mass of spores had oozed out from the opening of the pycnidium in the form of cream-colored drops. Proving the pathogenicity of the selected isolates was done by placing a piece of 5-day grown fungus on healthy fruits after making a wound with a sterile needle. Symptoms similar to those observed on the inoculated fruits were developed. The causative fungus was successfully isolated again from the inoculated fruits. Control fruits remained without symptoms. For molecular analysis, after extracting the DNA of the representative isolate, the TEF gene region was amplified and sequenced. The sequence of the sample was compared with the sequences available in Genbank (NCBI). BLAST analysis showed 99% similarity of this sequence with Cytospora punicae. Based on the investigations, this is the first report of the black spot disease of pomegranate fruit caused by C. punicae fungus in Mazandaran province.