Journal of Plant Pathology Archive

Abstract:

Pomegranate (Punica granatum) is one of the most important commercial fruit crop in eastern Mazandaran (Iran, 35°47’N, 50°34’E). During spring 2013, distinct dark brown spots were observed on pomegranate fruits, from which a fungus was isolated on standard otato dextrose agar (PDA) amended with streptomycin (0.05% w/v). The mycelium was white- grey turning olive green over time, and produced oval to cylindrical, hyaline, unicellular, aseptate conidia measuring 5-13×1.5-4 μm. Based on these morphological characters the mycete was tentatively identified as Colletotrichum gloeosporioides. The fungal internal transcribed spacer (ITS) region of r-DNA was then amplified using the primers ITS5/ITS4 sequenced locally and deposited under GeneBank accession No. KJ769129. A sequence similarity search performed using BLAST (Altschul et al. 1990) algorithm available via GenBank confirmed the identification as C. gloeosporioides. Pathogenicity tests were carried out by placing agar-discs from a six-day-old culture of the fungus onto five artificially injured pomegranate fruits, which were placed inside sterile plastic bags. Controls consisted of non- inoculated fruits. Symptoms were reproduced after six days only on inoculated fruits and the pathogen was subsequently re-isolated, fulfilling Koch’s postulates. To our knowledge, this is the first report of. C. gloeosporioides in pomegranate fruits in Iran.