RESISTANCE OF DIFFERENT ROCKET CULTIVARS TO WILT CAUSED BY STRAINS OF FUSARIUM OXYSPORUM UNDER ARTIFICIAL INOCULATION CONDITIONS

摘要

Serious losses occur in cultivated (Eruca vesicaria)and wild (Diplotaxis tenuifolia) rocket varieties infectedby Fusarium oxysporum f.sp. raphani in north-westernItaly. Forty-four varieties of cultivated and wild rocketwere chosen for resistance tests carried out under glassfrom June 2004 to June 2005, for the evaluation of resistance to Fusarium wilt. Roots of 30-day-old plantswere inoculated by dipping in a conidial suspension(106 CFU/ml) of the pathogen. Three trials were conducted using as inoculum strain Fus Rue 9A isolatedfrom a wild rocket variety and strain Fus Rue 13/03, isolated from cultivated rocket; both were strains of Fusarium oxysporum f.sp. raphani. Fus Rue 9A was found tobe the more virulent, and the majority of rocket varieties were susceptible or highly susceptible to it. Somerocket varieties showed resistance to Fus Rue 13/03. Inan overall disease index evaluation, varieties 7/02, 2/03,5/03, 6/03, 7/03, 11/03, 12/03, 20/03, 24/03, 6/04, and13/04 were at least partially resistant. The data obtainedindicate that only a few of the rocket varieties availablein Italy are resistant to Fusarium wilt. Moreover, differences in the host range of the two strains of F. oxysporum f.sp. raphani used suggest the presence of differentraces of the pathogen.