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.
Agriculture
Ali Hossainnia; Abbas Mohammadi
Abstract
Saffron is one of the most important herbs and spices in the East of Iran and its production is affected by various pathogens. This study is aimed at isolation, identification and pathogenicity detection of Alternaria alternata isolates as leave spot and corm rot of saffron agents. Soil samples and infected ...
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Saffron is one of the most important herbs and spices in the East of Iran and its production is affected by various pathogens. This study is aimed at isolation, identification and pathogenicity detection of Alternaria alternata isolates as leave spot and corm rot of saffron agents. Soil samples and infected plant tissues were collected from different areas of the Birjand plain (Birjand, Khusf and Sarbishe) during the years 2014-15. Alternaria species were isolated by potato dextrose agar medium and their morphological characteristics were studied on the potato carrot agar medium. For molecular studies, genomic DNA was extracted by the CTAB method and ribosomal subunits of fungal isolates were amplified using ITS1 and ITS4 primers. Based on morphological characteristics, 80 isolates of A. alternata were isolated. The ITS regions sequences of selected isolates had 100 similarities with A. alternata spices sequences in NCBI and MycoBank. These isolates caused chlorosis and necrosis on detached leaves, the inoculated corm was rotten and inoculated plants showed chlorosis and necrosis on leaves after 3-5 days. The results showed that A. alternata in the Birjand plain can cause corm rot and leaf chlorosis and necrosis is saffron. This study is the first report of the virulence of this fungus on saffron tissue in the East of Iran.
