Pathogenic and genetic characterization of Algerian isolates of Fusarium oxysporum f. sp. lentis by RAPD and AFLP analysis

Thirty-two isolates of Fusarium oxysporum f. sp. lentis were isolated from wilted lentil plants collected from different lentil growing areas in north-west Algeria. A pathogenicity test was performed for all isolates. Results indicated that the Fol isolates represent a single race but differ in their aggressiveness on the susceptible lines. The amount of genetic variation was evaluated by polymerase chain reaction (PCR) amplification with a set of 6 RAPD primers and 3 AFLP selective nucleotide primer pairs. All amplifications revealed scorable polymorphisms among the isolates, and a total of 8 polymorphic fragments were scored for the RAPD primers and 93 for the AFLP primers. Genetic similarity between each of the isolates was calculated by using the Jaccard similarity coefficient and cluster analysis was used to generate a dendrogram showing relationship between them. The isolates could be grouped into two subpopulations based on RAPD and AFLP analysis. Results obtained indicate that there is little genetic variability among a subpopulation of Fol as identified by RAPD and AFLP markers and that there is no apparent correlation with geographical origin or aggressiveness of isolates. Also, the data suggest that Fol isolates are derived from two genetically distinct clonal lineages.