Pathogenic and genetic variation of Iranian isolates of Fusarium oxysporum f. sp. betae

Pathogenicity and genetic variability of 13 Fusarium oxysporum isolates collected from sugar beet field of six provinces of Iran during 1999- 2008 were evaluated. Pathogenic variability of the isolates was determined using a root-dip assay in spore suspension in test tubes for four- week plants. The isolates were classified into strong and weak pathogenic groups. A total of 15 RAPD primers were used for the isolates genetic diversity evaluation. On this basis, high polymorphism was observed among the isolates. Cluster analysis (UPGMA) of the isolates using the MVSP software package classified them into five groups. There was a relationship between RAPD results and geographical origins of the isolates. However, no relationship was found between RAPD results and pathogenicity. Genomic DNA of isolates was amplified using ITS1 and ITS4 primers. The amplified DNA products of the isolates was digested by three restriction enzymes EcoR1, Taq1 and HaeIII. ITS- RFLP analysis showed similar banding pattern the isolates.