Selection methods for determining resistance of carnation cultivars to Fusarium oxysporum f.sp. dianthi

The level of resistance of carnation (Dianthus caryophyllus) cultivars to wilt caused by Fusarium oxysporum f.sp. dianthi was compared in root-dip-inoculated plants grown in pots (filled with tuff or sandy soil) in a greenhouse and plants grown in a field where the soil was artificially infested with the fungus. In the field, wilt symptoms appeared first in susceptible and subsequently in resistant cultivars; none was immune. Variations in the level of resistance were expressed either by different percentages of wilted plants (i.e. disease incidence) or by delayed disease progress as compared to a susceptible cultivar. The range of disease severity in the field, ranked on a scale from 0 to 4, was highly and significantly correlated with the percentage of diseased plants [...]