Virulence and vegetative compatibility of Algerian isolates of Fusarium oxysporum f. sp. lentis

Abstract

Thirty-two isolates of Fusarium oxysporum f. sp. lentis (Fol) were obtained from wilted lentil plants collected from different lentil growing areas in north-western Algeria. Pathogenicity tests were performed on all isolates. The isolates were also assessed for vegetative compatibility using nitrate non-utilising mutants (nit). Isolates that formed mutual heterokaryons were placed in the same vegetative compatibility group (VCG). The Fol isolates represented a single race but differed in their aggressiveness on susceptible lines. In the vegetative compatibility test, three types of nit were obtained (nit-1, nit-3 and Nit-M) on the basis of the phenotype. Nit-1 mutants were the most frequent (63%), followed by Nit-M (31%) and nit-3 (6%). On the basis of their ability to form heterokaryons, all the lentil pathogenic isolates were grouped into a single VCG 0471. This is an indication of the homogeneity of the Algerian Fol population.