Identification of Fusarium solani f. sp.cucurbitae races using morphological and molecular approaches

Fusarium solani f. sp.cucurbitae races cause crown, fruit and root rots of cucurbits and economic problem for farmers. The aim of this study is identification of Fusarium solani f. sp. cucurbitae races which collected in Shahrood, Jiroft and Varamin, provinces of Iran using morphological characteristics and fungal-specific primers. Symptomatic cucurbit plants were collected from different fields in three provinces. After isolation and purification of the causal agents, pathogenicity test and DNA extraction were performed. Specific primers for TEF-1α gene were used to distinguish among different species of Fusarium and Fusarium solani. The isolates that showed a specific 658 bp amplicon on agarose gel were selected for subsequent PCR assay in order to detection of F. solani f. sp. cucurbitae race 1 and 2. PCR assays were performed with taxon-specific primers race 1 (505bp PCR product) and race 2 (425bp PCR product). Some samples amplified a 505bp amplicon which is specific for race 1 and was in accordance with morphological characteristics. In these isolates, 5 septate macroconidia were dominant that is specific to Fusarium solani f. sp.cucurbitae race 1 macroconidia. None of the isolates were amplified by race 2 taxon-specific primers. Our study showed that, race 1 of F.solani is the dominant race of the pathogen in Shahrood, Jiroft and Varamin provinces which can help to implement effective disease management strategies.