Molecular characterization by PCR-ITS technique of Fusarium oxysporum isolated from tomato in Baghdad city

Abstract

The present study aimed to estimate the pathogenesis of Fusarium oxysporum isolates and identify them by molecular technique Polymerase Chain Reaction-Internal Transcript Spacer (PCR-ITS). A total of thirty Fusarium oxysporum isolates were isolated from infected tomato plants and diagnosed depending on 'morphological characteristics. The pathogenicity test was performed for thirty Fusarium oxysporum isolates. So it was proceduresteps that Genomic DNA was extracted from seven F. oxysporum isolates according to pathogenicity test by using'' ZR Fungal/Bacterial DNA'' MiniPrep™ kit. Seven F. oxysporum isolates showed high pathogenicity. The concentration and purity of the DNA extracted from the seven F. oxysporum isolates was (150 – 201) ng/µl and (1.4 -1.9) respectively. ITS gene was amplified by using PCR-ITS The sequencing results of amplified product of ITS gene from Fusarium oxysporum isolates indicated that all the seventh sequenced isolates where from one Formae speciales of Fusarium oxysporum as Fusarium oxysporum f. sp. Lycopersici. These results have been devoted to study genetic variability among the species involved in study. Molecular markers are highly important'' to focus on F. oxysporum isolates below'' the species level therefore, the DNA array containing "genus, species'' and forma specialis specific" detector'' for the detection and identification ''of F. oxysporum. Also, Cluster analysis and phylogenetic tree depending on genetic distance revealed the genetic relationship between the thirteen F. oxysporum isolates and confirmed sequencing analysis.