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.