Studies on the interactions between Fusarium oxysporum f.sp. lycopersici, Verticillium dahliae and Meloidogyne spp. in resistant and susceptible tomatoes

Abstract

The interactions between Verticillium dahliae, Fusarium oxysporum f. sp. lycopersici Race 1, Meloidogyne javanica, M. incognita and M. hapla on four hybrid tomato cultivars H1, H2, H3, and H4, bred for resistance to all pathogcns, and the susceptible cultivar 'Rouge de Marmande' after 56 days were investigated. The resistance of the hybrids was confirmed with no appreciable difference between the hybrids. Galling in the hybrids was due to M. hapla, the hybrids being less resistant to this species. Galling was significantly (P = 0.05) decreased in the presence of F. oxysporum f. sp. lycopersici. Meloidogyne spp. did not increase infection by V. dahliae or F. oxysporum f. sp. lycopersici. Infection by F. oxysporum f. sp. lycopersici was significantly (P = 0.05) increased in the presence of V. dalzliae plus Meloidogyne spp. Infection by V. clahliae was low throughout the experiment. V. dahliae was isolated more frequently in the presence of F. oxysporum f. sp. lycopersici. The decrease in galling in the presence of F. oxysporum f. sp. lycopersici was countered by the presence of V. dahliae. In the susceptible cultlvar and after 77 days, the presence of V. dahliae decreased the frequency of isolation of F. oxysporum f. sp. lycopersici, but there was no effect of F. oxysporum f. sp. lycopersici on isolation frequency of V. dahliue.