Agriculture
Nima Khaledi; Mahdi Rezaei; Mojtaba Alizadeh Farddarabad
Abstract
Fusarium rot disease is one of the most important fungal diseases of saffron corms worldwide, which can lead to a decrease in product yield and the quality of daughter corms produced. The objective of this study was to isolate and identify agents responsible for Fusarium corm rot in saffron, as well ...
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Fusarium rot disease is one of the most important fungal diseases of saffron corms worldwide, which can lead to a decrease in product yield and the quality of daughter corms produced. The objective of this study was to isolate and identify agents responsible for Fusarium corm rot in saffron, as well as to assess their pathogenicity. In order to determine the Fusarium species from saffron corms with rotting symptoms were sampled from the different fields in provinces of Hamadan, Golestan, Kerman, Kurdistan, Semnan, Kermanshah, Ardabil, East Azerbaijan, North Khorasan, Razavi Khorasan, Isfahan, and South Khorasan. After isolation and purification, fungal isolates were identified and confirmed based on morphological characteristics and species-specific primers. Also, the pathogenicity of the isolates was artificially tested in the greenhouse on saffron corms according to Koch’s principles. The results indicated that approximately 38.6% of the saffron corms were infected with fusarium rot disease in the 1 to 5% range. 33 isolates were identified based on morphological and molecular characteristics belonging to F. oxysporum (26 isolates, 78.8%) and F. solani sensu lato (7 isolates, 21.2%). The pathogenicity tests revealed that all Fusarium isolates were pathogenic, displaying varying levels of disease index.The result of the host range test of F. oxysporum on different plants revealed that all isolates caused wilting and yellowing of aerial organs, necrosis and rotting of underground organs on Gladiolus (Gladiolus communis L.), Irises (Iris germanica L.) and Crocus (Crocus vernus L.) and was called as F. oxysporum f. sp. gladioli. This is the first report on identification of F. oxysporum f. sp. gladioli from saffron fields in Malayer, Bijar, Kangavar, Parsabad, Marand, Natanz, Najafabad and f F. solani sensu lato from saffron fields in Azadshahr, Shirvan, Esfarayen, Kashmar, Najafabad, Boshruyeh on saffron corms. The findings of this research provide new insights into the health status of saffron corm against fusarium rot disease, which can be used for the revision of the national standard for saffron corms and determining suitable areas for certified corm production of saffron.
Nima Khaledi
Abstract
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 ...
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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,
