قارچ‌های همراه با شانکر انجیر و ارزیابی حساسیت ارقام انجیر ایرانی به بیمارگر غالب

In recent years, the most extensive collection of rainfed fig cultivars in Estahban, as well as other fig plantations in Fars Province, have been at the risk of decline due to the widespread dieback caused by the fig canker pathogens. During a four-year survey (2019–2022), fig samples (shoots, branches, and trunks) affected by fig canker were collected from four provinces, including Fars, Khuzestan, Lorestan and Mazandaran. The samples were subjected to fungal isolation and identification. Variations in the recorded disease symptoms, suggested four distinguishable types of fig cankers. Morphological and cultural characteristics, as well as multilocus phylogenetic analyses of the internal transcribed spacer (ITS) region of rDNA, RNA polymerase II second largest subunit (rpb2), the translation elongation factor 1-alpha (tef1), β-tubulin (tub2), and histone H3 (his) genes, were used for robust identification of recovered fungal isolates associated with fig canker. Morph-molecular studies indicated these isolates belong to five ascomycetes families, including Bionectriaceae, Botryosphaeriaceae, Diaporthaceae, Diatrypaceae and Nectriaceae. The pathogenicity of the isolates was assessed via the fulfillment of Koch’s postulates. This study described two new fig canker-associated pathogens, Stilbocrea banihashemiana sp. nov. (Bionectriaceae), and Neocosmospora caricae sp. nov. (Nectriaceae) from infected fig orchards in Fars Province. Also, some previously described ascomycetes, including Albonectria rigidiuscula, Fusarium annulatum, and Neocosmospora metavorans from Nectriaceae, Peroneutypa scoparia from Diatrypaceae and three Botryosphaeriaceae species, Botryosphaeria dothidea, Neofusicoccum parvum, and Neoscytalidium dimidiatum were introduced as fig canker-associated pathogen in Iran. However, the previously reported Diaporthe cinerascens (Diaporthaceae) was the main cause of the fig canker. Evaluation of fig cultivars susceptibility to D. cinerascens were conducted on tree saplings of 10 one-year-old Iranian fig cultivars, including commercial dried fig ('Sabz' and 'Payves'), fresh fig ('Matti', 'Shah Anjeer,' 'Siah', and 'Siah-e-Dorosht'), wild ('Dehdez', and 'Gilasi') and hybrid ('C8-M' ('Sabz'×'Khormaei'), and 'C8-F' ('Sabz'×'Khormaei') cultivars. The susceptibility of these 10 droughts and/or salinity-tolerant fig cultivars to a highly aggressive D. cinerascens isolate was evaluated based on five pathogenicity characteristics (lesion length, lesion width, numbers of pycnidia, latent period, and length of wood discoloration). These cultivars were clustered into non-susceptible ('Matti' cultivar), moderately -susceptible (the majority of the cultivars), and susceptible cultivars ('Dehdez' and 'Gilasi'). Also, we could identify drought tolerant cultivar 'Matti' as a non-susceptible cultivar to fig Diaporthe canker that can be used as a progenitor or rootstock in future breeding or horticulture programs. This study was a comprehensive revision on fig canker-associated pathogens in Iran that is critical in understanding fig canker epidemiology and adopting sustainable management practices for the diseases.