Morphological and Molecular Identification of Fusarium Associated with Beans in Selseleh County

Abstract

Fusarium species are among the important factors in bean contamination worldwide, some of which cause wilting and rotting of crowns and roots in beans. Identifying Fusarium species is necessary to prevent wilting and root and crown rot diseases in bean fields. In this study, 60 fungal isolates showing disease symptoms were collected from the bean samples. The rhizosphere, including the Fusarium species complex of Fusarium solani, F. oxysporum, F. equiseti, F. acuminatum, and F. clamydosporum species with frequencies 41.6, 31.3, 16.6, 6.6, and 3.3%, respectively, were isolated from the bean fields of Selseleh County, Lorestan province. The isolates were morphologically identified using Leslie and Summerell’s identification key. In this study, 13 isolates of three Fusarium species, including F. oxysporum, F. solani, and F. equiseti were used to identify more precise with both morphological and molecular methods and also investigate their phylogenetic relationship with each other and with the reference species registered in the gene bank and ISTH. TEF-1α gene region was amplified using PCR, and the amplified fragments were sequenced. Nucleotide sequences were entered in Fusarium ID database for molecular identification of isolates based on the TEF-1α gene, and a phylogenetic tree was drawn. F. solani and F. oxysporum species were reported to be the most abundant and harmful Fusarium species causing bean root rot, which can be considered a limiting factor in bean cultivation in Selseleh County. Furthermore, the other species, which have low frequency and poor distribution, did not have a significant role in bean root rot in these fields.

Keywords

• fusarium
• legumes
• molecular identification
• tef-1α gene