Pathogenic and molecular detection of Fusarium oxysporum f. sp. albedinis isolates from different areas in southwest Algeria

Purpose: To investigate the intra-specific variations in eleven Fusarium oxysporum isolates from infected date palm using pathogenicity and molecular methods.Methods: Eleven isolates of Fusarium oxysporum obtained from infected date palms in the south-west region of Algeria were subjected to confirmatory test using a specific polymerase chain reaction (PCR) technique with the primer pairs, TL3-FOA28 and BIO3-FOA1. Polymorphism in the 5’ domain of the large subunit rRNA was investigated. Small libraries of the domain, amplified by the primer pair, LR3/LROR, were constructed and the inserts sequenced.Results: The 11 isolates of Fusarium oxysporum collected from the infected date palm were confirmed as Fusarium oxysporun f. sp albedinis. Results from the investigation of polymorphism in the 5’ domain of the large subunit rRNA revealed that the sequences were 100 % homologous or extremely close (> 99.4 %, differing by no more than one to three nucleotides) to several Fusarium oxysporum sequences. In addition, F. inflexum (U34548.1) was highly homologous to one of the F. oxysporum f. sp. albedinis.Conclusion: The sequences of the 11 isolates are almost 100 % homologous to several F. oxysporum species. It is noteworthy that a sequence highly homologous to one of the F. oxysporum f. sp. albedinis is obtainable from a different species, F. inflexum (U34548.1).Keywords: Fusarium oxysporum f. sp. albedinis, Date palm, rRNA gene polymorphism