Vegetative compatibility in populations of Fusarium oxysporum from wild carnation

Wild carnation plants (Dianthus strictus) were collected from undisturbed, non-cultivated soils at four sites in Israel. Isolates of Fusarium oxysporum obtained from the roots of these plants were characterized by means of the vegetative-compatibility grouping method, using nitrate non-utilizing (nit) mutants to determine possible relationships among them and with the carnation wilt pathogen F. oxysporum f.sp. dianthi. No relatedness was evident between any of the isolates, except for five out of 26 combinations of isolates originating from the same plant. Wild populations are therefore diverse and do not constitute a distinct carnation-specific vegetative-compatibility group of F. oxysporum. None of 33 isolates originating from root tissues of wild carnation were vegetatively compatible with F. oxysporum f.sp. dianthi.