Morphological and molecular identification of Fusarium spp. associated with carnation Dianthus caryophyllus in Mahallat, Iran

Carnation is an ornamental plant of economic importance worldwide. Fusarium fungus is one of the critical infectious agents of Carnation in Mahallat city. Some species of Fusarium cause wilting and crown and root rot in carnation. In this study, 20 fungal isolates of Fusarium were isolated from diseased carnation plants and rhizosphere samples from Carnation greenhouses in Mahallat. The isolates were identified morphologically using Leslie and Summerell’s identification key. Amplification of the TEF-1α gene region was done using ef1 and ef2 primers. Amplified fragments were purified and sequenced, and the nucleotide sequences were introduced in the Fusarium ID database for molecular identification of isolates based on the TEF-1α gene. A phylogenetic tree was also drawn. The results showed that Fusarium isolates were categorized into five species: F14 was identified as Fusarium brachygibbosum morphologically and F. solani molecularly. F6 was morphologically and molecularly identified as F. solani, F10 identified as Fusarium culmorum. All crown and root isolates (F11, F12, F13, F15, F16, F17, F18, F9, and F20) were identified as F. oxysporum. The rhizosphere isolates of F1, F2, F3, F4, F5, F7, F8, and F9 were identified as Fusarium proliferatum. This study shows that the use of the TEF-1α gene for molecular identification of Fusarium isolates is a relatively accurate, fast, and straightforward method for detecting species and can be used in plant pathological studies. Identifying the pathogen is the first step to controlling the disease.