گونه هایPhaeoacremonium و Coniolariella gamsii همراه با سرخشکیدگی و شانکر درختان انجیر (Ficus spp.) در ایران

The genus Phaeoacremonium (Togniniaceae, Togniniales) presently contains 60 species. Species of this genus are found in various woody plants as endophytes or as vascular plant pathogen. The occurrence of fungal trunk pathogens associated with the decline of fig trees (Ficus spp.) were determined in several surveys conducted in fig orchards in Kerman and Fars provinces. Samples were collected between 2016 and 2017 from trunk and branches of trees showing dieback and canker symptoms. All samples were taken to the laboratory to perform fungal isolations and identification. Each sample was first cut in cross section and different internal wood lesion types were recorded. Wood pieces (approximately 4×4 mm) were cut from the margins between necrotic and healthy tissue and surface-sterilised by soaking in 0.5% NaOCl solution for 2 min and then rinsed twice with sterile distilled water. Following ste‌rilisation, wood segments were dried on sterile paper and then placed on potato-dextrose agar (PDA) plates. Plates were incubated at 25°C for 10-15 days. Single spore cultures were made from all isolates to obtain pure colonies. The initial identification of isolates was made based on visual characteristics such as colony color, colony texture and microscopic structures. Representative isolates that were identified using morphological technique were confirmed by molecular method. Total genomic DNA from selected isolates was extracted from 15 to 20 day-old cultures using the CTAB (cetyl trimethylammonium bromide) method. The internal transcribed spacer (ITS) region of the ribosomal RNA operon (ITS1-5.8S ITS2), and part of the β-tubulin (BT) were amplified using the ITS1/ITS4 and T1/Bt2b primers, respectively. According to morphological and molecular data, 37 fungal isolates include of Phaeoacremonium parasiticum (30 isolates), Pm. sicilianum (five isolates) and Coniolariella gamsii (two isolates) were recovered from two species of Ficus as Ficus carica and Ficus pesudocarica. This is the first report of Pm. parasiticum and Pm. sicilianum on F. pesudocarica and Coniolarella gamsii on F. caricain the world. The present study is also the first report of Pm. parasiticum from F. carica in Iran.