Vegetative Compatibility Among Races of Fusarium oxysporum f. sp. cubense. R. C. Ploetz, Trec, University of Florida, IFAS, 18905 S.W. 280th Street, Homestead 33031. J. C. Correll, Department of Plant Pathology, University of California, Berkeley 94720. Plant Dis. 72:325-328. Accepted for publication 30 October 1987. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0325.

Isolates of Fusarium oxysporum f. sp. cubense (incitant of Panama disease of Musa and Heliconia spp.), collected from Australia, the Canary Islands, the Comores Islands, Honduras, Jamaica, Malaysia, the Philippines, South Africa, Taiwan, and the United States were characterized for vegetative compatibility by using nitrogen metabolism mutants. Isolates belonged to race 1, 2, or 4 or were of unknown race. Eleven vegetative compatibility groups (VCGs) were identified among the 96 isolates in this collection. In general, there was a good correlation between VCG and race among isolates for which race was known. Six VCGs were composed of isolates of only a single race and five were composed of isolates representing two different races. Race 4 isolates belonged to at least three different VCGs, indicating genetic diversity among strains of this race. The use of representative strains from these VCGs is suggested when banana selections are screened for resistance to race 4 or other variants of this pathogen. The use of vegetative compatibility to characterize isolates of unknown race is discussed.

Keyword(s): Cavendish, Fusarium wilt of banana, nit mutants.