Identification of Fusarium oxysporum f. sp. basilici isolated from soil, basil seed, and plants by RAPD analysis

Fifty-two isolates of Fusarium oxysporum, obtained from infected basil plants, seed, flower
residues, and soil from different growing areas in Italy and Israel, were analyzed by random
amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR), coupled to a DNA
extraction protocol from colonies grown on Fusarium-selective medium. In a pathogenicity
assay, 35 isolates caused 32 to 92% disease on seedlings of the highly susceptible basil cultivar
Fine verde, while 17 isolates were nonpathogenic on basil. Thirty of the F. oxysporum f. sp.
basilici isolates obtained from soil or wilted plants gave identical amplification patterns using
31 different random primers. All tested primers allowed clear differentiation of F. oxysporum f.
sp. basilici from representatives of other formae speciales and from nonpathogenic strains of F.
oxysporum. RAPD profiles obtained from DNA of isolates extracted directly from cultures
grown on Fusarium selective medium were identical to those obtained from DNA extracted
from lyophilized mycelia