VEGETATIVE COMPATIBILITY GROUPS OF FUSARIUM-OXYSPORUM F-SP DIANTHI FROM PLANTS AND THE RHIZOSPHERE OF CARNATION IN GREECE

investigation was carried out into the vegetative compatibility patter ns of a collection of 100 Greek Fusarium isolates from carnation and s even Israeli isolates, members of vegetative compatibility group (VCG) 0021 of Fusarium oxysporum f.sp. dianthi (F.o.d.). Of these Greek iso lates, 95 were classified as F.o.d. based on pathogenicity on the cult ivar White Sim. These isolates were obtained from various carnation cu ltivars grown in plastic houses or from outdoor cultivation, originati ng from several parts of the country. Nitrate non-utilizing (nit) muta nts were generated from all isolates and used for complementation test s. Representative mutants were tested against nit mutants of isolates of F. oxysporum f.sp. dianthi from France, Germany, Italy, The Netherl ands and USA. All Greek F.o.d. isolates were found to belong to the pr eviously described VCG 0021. Non-pathogenic isolates of F. oxysporum, isolates belonging to other special forms of F. oxysporum, and one iso late of F. proliferatum were not compatible with any isolate in this c ompatibility group. Our data demonstrate homogeneity of the F.o.d. pop ulation in Greece; based on correlations found, VCG and race designati on, this population probably consists mainly or entirely of F. oxyspor um f.sp. dianthi race 2.