Evaluation of cell wall degrading enzymes of Fusarium species associated with root and corm of saffron in South Khorasan province

The aim of this study is to identify  Fusarium species associated with root and corm of saffron and evaluate extracellular enzyme activity secreted by them. In order to study the species of Fusarium, a total of 53 root and corm samples were randomly collected from saffron fields of the South Khorasan province during 2017 growing season. After washing the samples with sterile water and disinfected the surface with 1% sodium hypochlorite, small pieces of root and corm were cultured on general and specific culture media. Purification of fungal colonies was performed using single spore and hyphal tip methods on 2% water agar medium. Identification of fungi based on the microscopic and morphological characteristics was performed with valid identification keys. The F. oxysporum, F. graminearum, F. culmorum and F. proliferatum species were identified based on morphological characters. The results obtained from molecular analysis using species-specific primers confirm morphological identification. The results reveal that 22.6% of saffron samples are contaminated by Fusarium species. F. oxysporum is the predominant species with the highest isolation frequency in samples of 9.4% followed by F. culmorum (5.7%), F. proliferatum (3.8%) and F. graminearum (3.8%) based on morphological and molecular observations,